diff --git a/CMakeLists.txt b/CMakeLists.txt
index 8dc46d710..aea012b61 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -27,29 +27,33 @@ endif ()
 #set(CRYPTOPP_INCLUDE_DIR "../cryptopp562" CACHE FILEPATH "" FORCE)
 #set(CRYPTOPP_LIBRARIES "../cryptopp562" CACHE FILEPATH "" FORCE)
 
+set(CRYPTOPP_INCLUDE_DIR CACHE FILEPATH "" FORCE)
+set(CRYPTOPP_LIBRARIES CACHE FILEPATH "" FORCE)
+
 # Look for availabe Crypto++ version and if it is >= 5.6.2
 #if(CRYPTOPP_INCLUDE_DIR AND CRYPTOPP_LIBRARIES)
 #	   set(CRYPTOPP_FOUND TRUE)
 #	   message(STATUS "Found Crypto++: ${CRYPTOPP_INCLUDE_DIR}, ${CRYPTOPP_LIBRARIES}")
 #else()
-       find_path(CRYPTOPP_INCLUDE_DIR cryptlib.h
-               /usr/include/cryptopp
-               /usr/include/crypto++
-               /usr/local/include/cryptopp
-               /usr/local/include/crypto++
-               /opt/local/include/cryptopp
-               /opt/local/include/crypto++
-               )
-       find_library(CRYPTOPP_LIBRARIES NAMES cryptoppeth cryptopp
-               PATHS
-               /usr/lib
-               /usr/local/lib
-               /opt/local/lib
-               )
-       if(CRYPTOPP_INCLUDE_DIR AND CRYPTOPP_LIBRARIES)
+	   find_path(ID cryptlib.h
+			   /usr/include/cryptopp
+			   /usr/include/crypto++
+			   /usr/local/include/cryptopp
+			   /usr/local/include/crypto++
+			   /opt/local/include/cryptopp
+			   /opt/local/include/crypto++
+			   )
+	   find_library(LS NAMES cryptoppeth cryptopp
+			   PATHS
+			   /usr/lib
+			   /usr/local/lib
+			   /opt/local/lib
+			   )
+
+	   if(ID AND LS)
                set(CRYPTOPP_FOUND TRUE)
-               message(STATUS "Found Crypto++: ${CRYPTOPP_INCLUDE_DIR}, ${CRYPTOPP_LIBRARIES}")
-               set(_CRYPTOPP_VERSION_HEADER ${CRYPTOPP_INCLUDE_DIR}/config.h)
+			   message(STATUS "Found Crypto++: ${ID}, ${LS}")
+			   set(_CRYPTOPP_VERSION_HEADER ${ID}/config.h)
                if(EXISTS ${_CRYPTOPP_VERSION_HEADER})
                        file(STRINGS ${_CRYPTOPP_VERSION_HEADER} _CRYPTOPP_VERSION REGEX "^#define CRYPTOPP_VERSION[ \t]+[0-9]+$")
                        string(REGEX REPLACE "^#define CRYPTOPP_VERSION[ \t]+([0-9]+)" "\\1" _CRYPTOPP_VERSION ${_CRYPTOPP_VERSION})
@@ -58,7 +62,9 @@ endif ()
                                set(CRYPTOPP_INCLUDE_DIR "../cryptopp562" CACHE FILEPATH "" FORCE)
                                set(CRYPTOPP_LIBRARIES "../cryptopp562" CACHE FILEPATH "" FORCE)
                        else()
-                               message(STATUS "Crypto++ found and version greater or equal to 5.6.2")
+								set(CRYPTOPP_INCLUDE_DIR ${ID}  CACHE FILEPATH "" FORCE)
+							   set(CRYPTOPP_LIBRARIES ${LS}  CACHE FILEPATH "" FORCE)
+							   message(STATUS "Crypto++ found and version greater or equal to 5.6.2")
                        endif()
                endif()
        else()
@@ -75,6 +81,7 @@ if(CRYPTOPP_FOUND)
 	link_directories(${CRYPTOPP_LIBRARIES})
 endif()
 
+add_subdirectory(secp256k1)
 add_subdirectory(libethereum)
 add_subdirectory(test)
 add_subdirectory(eth)
diff --git a/eth/CMakeLists.txt b/eth/CMakeLists.txt
index fd60633ad..0676b34fe 100644
--- a/eth/CMakeLists.txt
+++ b/eth/CMakeLists.txt
@@ -12,7 +12,6 @@ find_package(Threads REQUIRED)
 target_link_libraries(eth ethereum)
 target_link_libraries(eth miniupnpc)
 target_link_libraries(eth leveldb)
-target_link_libraries(eth secp256k1)
 target_link_libraries(eth ${CRYPTOPP_LIBRARIES})
 target_link_libraries(eth gmp)
 target_link_libraries(eth boost_system)
diff --git a/eth/main.cpp b/eth/main.cpp
index 864247280..db1bfc871 100644
--- a/eth/main.cpp
+++ b/eth/main.cpp
@@ -48,6 +48,16 @@ void writeFile(std::string const& _file, bytes const& _data)
 	ofstream(_file, ios::trunc).write((char const*)_data.data(), _data.size());
 }
 
+bool isTrue(std::string const& _m)
+{
+	return _m == "on" || _m == "yes" || _m == "true" || _m == "1";
+}
+
+bool isFalse(std::string const& _m)
+{
+	return _m == "off" || _m == "no" || _m == "false" || _m == "0";
+}
+
 int main(int argc, char** argv)
 {
 	short listenPort = 30303;
@@ -95,13 +105,13 @@ int main(int argc, char** argv)
 		else if ((arg == "-n" || arg == "--upnp") && i + 1 < argc)
 		{
 			string m = argv[++i];
-			if (m == "on")
+			if (isTrue(m))
 				upnp = true;
-			else if (m == "off")
+			else if (isFalse(m))
 				upnp = false;
 			else
 			{
-				cerr << "Invalid UPnP option: " << argv[i] << endl;
+				cerr << "Invalid UPnP option: " << m << endl;
 				return -1;
 			}
 		}
@@ -114,12 +124,20 @@ int main(int argc, char** argv)
 		else if ((arg == "-d" || arg == "--path" || arg == "--db-path") && i + 1 < argc)
 			dbPath = argv[++i];
 		else if ((arg == "-m" || arg == "--mining") && i + 1 < argc)
-			if (string(argv[++i]) == "on")
+		{
+			string m = argv[++i];
+			if (isTrue(m))
 				mining = ~(eth::uint)0;
-			else if (string(argv[i]) == "off")
+			else if (isFalse(m))
 				mining = 0;
+			else if (int i = stoi(m))
+				mining = i;
 			else
-				mining = atoi(argv[i]);
+			{
+				cerr << "Unknown mining option: " << m << endl;
+				return -1;
+			}
+		}
 		else if ((arg == "-v" || arg == "--verbosity") && i + 1 < argc)
 			verbosity = atoi(argv[++i]);
 		else if ((arg == "-x" || arg == "--peers") && i + 1 < argc)
diff --git a/libethereum/CMakeLists.txt b/libethereum/CMakeLists.txt
index 66ce33dfd..b8e568198 100644
--- a/libethereum/CMakeLists.txt
+++ b/libethereum/CMakeLists.txt
@@ -6,6 +6,8 @@ file(GLOB HEADERS "*.h")
 
 find_package(Threads REQUIRED)
 
+include_directories(../secp256k1)
+
 target_link_libraries(ethereum secp256k1)
 target_link_libraries(ethereum miniupnpc)
 target_link_libraries(ethereum leveldb)
diff --git a/libethereum/State.cpp b/libethereum/State.cpp
index 1865a18c3..00d2f33e8 100644
--- a/libethereum/State.cpp
+++ b/libethereum/State.cpp
@@ -96,6 +96,13 @@ State::State(Address _coinbaseAddress, Overlay const& _db): m_db(_db), m_state(&
 	cout << "State::State: state root initialised to " << m_state.root() << endl;
 
 	m_previousBlock = BlockInfo::genesis();
+	cnote << "Genesis headerhash-nononce:" << m_previousBlock.headerHashWithoutNonce();
+	{
+		RLPStream s;
+		m_previousBlock.fillStream(s, false);
+		cnote << RLP(s.out());
+		cnote << asHex(s.out());
+	}
 	resetCurrent();
 
 	assert(m_state.root() == m_previousBlock.stateRoot);
diff --git a/secp256k1/CMakeLists.txt b/secp256k1/CMakeLists.txt
new file mode 100644
index 000000000..4911990f9
--- /dev/null
+++ b/secp256k1/CMakeLists.txt
@@ -0,0 +1,13 @@
+cmake_policy(SET CMP0015 NEW)
+
+set(CMAKE_ASM_COMPILER "yasm")
+
+#aux_source_directory(. SRC_LIST)
+add_library(secp256k1 secp256k1.c field_5x52_asm.asm)
+
+#set(CMAKE_C_FLAGS "-DUSE_FIELD_5X52 -DUSE_FIELD_5X52_ASM -DUSE_NUM_OPENSSL -DUSE_FIELD_INV_BUILTIN")
+#target_link_libraries(secp256k1 crypto)
+set(CMAKE_C_FLAGS "-std=c99 -DUSE_FIELD_GMP -DUSE_NUM_GMP -DUSE_FIELD_INV_NUM")
+target_link_libraries(secp256k1 gmp)
+
+
diff --git a/secp256k1/COPYING b/secp256k1/COPYING
new file mode 100644
index 000000000..4522a5990
--- /dev/null
+++ b/secp256k1/COPYING
@@ -0,0 +1,19 @@
+Copyright (c) 2013 Pieter Wuille
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in
+all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+THE SOFTWARE.
diff --git a/secp256k1/ecdsa.h b/secp256k1/ecdsa.h
new file mode 100644
index 000000000..d9faaa3e8
--- /dev/null
+++ b/secp256k1/ecdsa.h
@@ -0,0 +1,28 @@
+// Copyright (c) 2013 Pieter Wuille
+// Distributed under the MIT/X11 software license, see the accompanying
+// file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
+#ifndef _SECP256K1_ECDSA_
+#define _SECP256K1_ECDSA_
+
+#include "num.h"
+
+typedef struct {
+    secp256k1_num_t r, s;
+} secp256k1_ecdsa_sig_t;
+
+void static secp256k1_ecdsa_sig_init(secp256k1_ecdsa_sig_t *r);
+void static secp256k1_ecdsa_sig_free(secp256k1_ecdsa_sig_t *r);
+
+int static secp256k1_ecdsa_pubkey_parse(secp256k1_ge_t *elem, const unsigned char *pub, int size);
+void static secp256k1_ecdsa_pubkey_serialize(secp256k1_ge_t *elem, unsigned char *pub, int *size, int compressed);
+int static secp256k1_ecdsa_sig_parse(secp256k1_ecdsa_sig_t *r, const unsigned char *sig, int size);
+int static secp256k1_ecdsa_sig_serialize(unsigned char *sig, int *size, const secp256k1_ecdsa_sig_t *a);
+int static secp256k1_ecdsa_sig_verify(const secp256k1_ecdsa_sig_t *sig, const secp256k1_ge_t *pubkey, const secp256k1_num_t *message);
+int static secp256k1_ecdsa_sig_sign(secp256k1_ecdsa_sig_t *sig, const secp256k1_num_t *seckey, const secp256k1_num_t *message, const secp256k1_num_t *nonce, int *recid);
+int static secp256k1_ecdsa_sig_recover(const secp256k1_ecdsa_sig_t *sig, secp256k1_ge_t *pubkey, const secp256k1_num_t *message, int recid);
+void static secp256k1_ecdsa_sig_set_rs(secp256k1_ecdsa_sig_t *sig, const secp256k1_num_t *r, const secp256k1_num_t *s);
+int static secp256k1_ecdsa_privkey_parse(secp256k1_num_t *key, const unsigned char *privkey, int privkeylen);
+int static secp256k1_ecdsa_privkey_serialize(unsigned char *privkey, int *privkeylen, const secp256k1_num_t *key, int compressed);
+
+#endif
diff --git a/secp256k1/ecmult.h b/secp256k1/ecmult.h
new file mode 100644
index 000000000..856bd284f
--- /dev/null
+++ b/secp256k1/ecmult.h
@@ -0,0 +1,19 @@
+// Copyright (c) 2013 Pieter Wuille
+// Distributed under the MIT/X11 software license, see the accompanying
+// file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
+#ifndef _SECP256K1_ECMULT_
+#define _SECP256K1_ECMULT_
+
+#include "num.h"
+#include "group.h"
+
+static void secp256k1_ecmult_start(void);
+static void secp256k1_ecmult_stop(void);
+
+/** Multiply with the generator: R = a*G */
+static void secp256k1_ecmult_gen(secp256k1_gej_t *r, const secp256k1_num_t *a);
+/** Double multiply: R = na*A + ng*G */
+static void secp256k1_ecmult(secp256k1_gej_t *r, const secp256k1_gej_t *a, const secp256k1_num_t *na, const secp256k1_num_t *ng);
+
+#endif
diff --git a/secp256k1/field.h b/secp256k1/field.h
new file mode 100644
index 000000000..7d187d02c
--- /dev/null
+++ b/secp256k1/field.h
@@ -0,0 +1,99 @@
+// Copyright (c) 2013 Pieter Wuille
+// Distributed under the MIT/X11 software license, see the accompanying
+// file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
+#ifndef _SECP256K1_FIELD_
+#define _SECP256K1_FIELD_
+
+/** Field element module.
+ *
+ *  Field elements can be represented in several ways, but code accessing
+ *  it (and implementations) need to take certain properaties into account:
+ *  - Each field element can be normalized or not.
+ *  - Each field element has a magnitude, which represents how far away
+ *    its representation is away from normalization. Normalized elements
+ *    always have a magnitude of 1, but a magnitude of 1 doesn't imply
+ *    normality.
+ */
+
+#if defined(USE_FIELD_GMP)
+#include "field_gmp.h"
+#elif defined(USE_FIELD_10X26)
+#include "field_10x26.h"
+#elif defined(USE_FIELD_5X52)
+#include "field_5x52.h"
+#else
+#error "Please select field implementation"
+#endif
+
+typedef struct {
+    secp256k1_num_t p;
+} secp256k1_fe_consts_t;
+
+static const secp256k1_fe_consts_t *secp256k1_fe_consts = NULL;
+
+/** Initialize field element precomputation data. */
+void static secp256k1_fe_start(void);
+
+/** Unload field element precomputation data. */
+void static secp256k1_fe_stop(void);
+
+/** Normalize a field element. */
+void static secp256k1_fe_normalize(secp256k1_fe_t *r);
+
+/** Set a field element equal to a small integer. Resulting field element is normalized. */
+void static secp256k1_fe_set_int(secp256k1_fe_t *r, int a);
+
+/** Verify whether a field element is zero. Requires the input to be normalized. */
+int  static secp256k1_fe_is_zero(const secp256k1_fe_t *a);
+
+/** Check the "oddness" of a field element. Requires the input to be normalized. */
+int  static secp256k1_fe_is_odd(const secp256k1_fe_t *a);
+
+/** Compare two field elements. Requires both inputs to be normalized */
+int  static secp256k1_fe_equal(const secp256k1_fe_t *a, const secp256k1_fe_t *b);
+
+/** Set a field element equal to 32-byte big endian value. Resulting field element is normalized. */
+void static secp256k1_fe_set_b32(secp256k1_fe_t *r, const unsigned char *a);
+
+/** Convert a field element to a 32-byte big endian value. Requires the input to be normalized */
+void static secp256k1_fe_get_b32(unsigned char *r, const secp256k1_fe_t *a);
+
+/** Set a field element equal to the additive inverse of another. Takes a maximum magnitude of the input
+ *  as an argument. The magnitude of the output is one higher. */
+void static secp256k1_fe_negate(secp256k1_fe_t *r, const secp256k1_fe_t *a, int m);
+
+/** Multiplies the passed field element with a small integer constant. Multiplies the magnitude by that
+ *  small integer. */
+void static secp256k1_fe_mul_int(secp256k1_fe_t *r, int a);
+
+/** Adds a field element to another. The result has the sum of the inputs' magnitudes as magnitude. */
+void static secp256k1_fe_add(secp256k1_fe_t *r, const secp256k1_fe_t *a);
+
+/** Sets a field element to be the product of two others. Requires the inputs' magnitudes to be at most 8.
+ *  The output magnitude is 1 (but not guaranteed to be normalized). */
+void static secp256k1_fe_mul(secp256k1_fe_t *r, const secp256k1_fe_t *a, const secp256k1_fe_t *b);
+
+/** Sets a field element to be the square of another. Requires the input's magnitude to be at most 8.
+ *  The output magnitude is 1 (but not guaranteed to be normalized). */
+void static secp256k1_fe_sqr(secp256k1_fe_t *r, const secp256k1_fe_t *a);
+
+/** Sets a field element to be the (modular) square root of another. Requires the inputs' magnitude to
+ *  be at most 8. The output magnitude is 1 (but not guaranteed to be normalized). */
+void static secp256k1_fe_sqrt(secp256k1_fe_t *r, const secp256k1_fe_t *a);
+
+/** Sets a field element to be the (modular) inverse of another. Requires the input's magnitude to be
+ *  at most 8. The output magnitude is 1 (but not guaranteed to be normalized). */
+void static secp256k1_fe_inv(secp256k1_fe_t *r, const secp256k1_fe_t *a);
+
+/** Potentially faster version of secp256k1_fe_inv, without constant-time guarantee. */
+void static secp256k1_fe_inv_var(secp256k1_fe_t *r, const secp256k1_fe_t *a);
+
+
+/** Convert a field element to a hexadecimal string. */
+void static secp256k1_fe_get_hex(char *r, int *rlen, const secp256k1_fe_t *a);
+
+/** Convert a hexadecimal string to a field element. */
+void static secp256k1_fe_set_hex(secp256k1_fe_t *r, const char *a, int alen);
+
+#endif
diff --git a/secp256k1/field_10x26.h b/secp256k1/field_10x26.h
new file mode 100644
index 000000000..d544139e8
--- /dev/null
+++ b/secp256k1/field_10x26.h
@@ -0,0 +1,19 @@
+// Copyright (c) 2013 Pieter Wuille
+// Distributed under the MIT/X11 software license, see the accompanying
+// file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
+#ifndef _SECP256K1_FIELD_REPR_
+#define _SECP256K1_FIELD_REPR_
+
+#include <stdint.h>
+
+typedef struct {
+    // X = sum(i=0..9, elem[i]*2^26) mod n
+    uint32_t n[10];
+#ifdef VERIFY
+    int magnitude;
+    int normalized;
+#endif
+} secp256k1_fe_t;
+
+#endif
diff --git a/secp256k1/field_5x52.h b/secp256k1/field_5x52.h
new file mode 100644
index 000000000..9d5de2cc4
--- /dev/null
+++ b/secp256k1/field_5x52.h
@@ -0,0 +1,19 @@
+// Copyright (c) 2013 Pieter Wuille
+// Distributed under the MIT/X11 software license, see the accompanying
+// file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
+#ifndef _SECP256K1_FIELD_REPR_
+#define _SECP256K1_FIELD_REPR_
+
+#include <stdint.h>
+
+typedef struct {
+    // X = sum(i=0..4, elem[i]*2^52) mod n
+    uint64_t n[5];
+#ifdef VERIFY
+    int magnitude;
+    int normalized;
+#endif
+} secp256k1_fe_t;
+
+#endif
diff --git a/secp256k1/field_5x52_asm.asm b/secp256k1/field_5x52_asm.asm
new file mode 100644
index 000000000..9237b3687
--- /dev/null
+++ b/secp256k1/field_5x52_asm.asm
@@ -0,0 +1,463 @@
+	;; Added by Diederik Huys, March 2013
+	;;
+	;; Provided public procedures:
+	;; 	secp256k1_fe_mul_inner
+	;; 	secp256k1_fe_sqr_inner
+	;;
+	;; Needed tools: YASM (http://yasm.tortall.net)
+	;;
+	;; 
+
+	BITS 64
+
+	;;  Procedure ExSetMult
+	;;  Register Layout:
+	;;  INPUT: 	rdi	= a->n
+	;; 	   	rsi  	= b->n
+	;; 	   	rdx  	= r->a
+	;; 
+	;;  INTERNAL:	rdx:rax  = multiplication accumulator
+	;; 		r9:r8    = c
+	;; 		r10-r13  = t0-t3
+	;; 		r14	 = b.n[0] / t4
+	;; 		r15	 = b.n[1] / t5
+	;; 		rbx	 = b.n[2] / t6
+	;; 		rcx	 = b.n[3] / t7
+	;; 		rbp	 = Constant 0FFFFFFFFFFFFFh / t8
+	;; 		rsi	 = b.n / b.n[4] / t9
+
+	GLOBAL secp256k1_fe_mul_inner
+	ALIGN 32
+secp256k1_fe_mul_inner:
+	push rbp
+	push rbx
+	push r12
+	push r13
+	push r14
+	push r15
+	push rdx
+	mov r14,[rsi+8*0]	; preload b.n[0]. This will be the case until
+				; b.n[0] is no longer needed, then we reassign
+				; r14 to t4
+	;; c=a.n[0] * b.n[0]
+   	mov rax,[rdi+0*8]	; load a.n[0]
+	mov rbp,0FFFFFFFFFFFFFh
+	mul r14			; rdx:rax=a.n[0]*b.n[0]
+	mov r15,[rsi+1*8]
+	mov r10,rbp		; load modulus into target register for t0
+	mov r8,rax
+	and r10,rax		; only need lower qword of c
+	shrd r8,rdx,52
+	xor r9,r9		; c < 2^64, so we ditch the HO part 
+
+	;; c+=a.n[0] * b.n[1] + a.n[1] * b.n[0]
+	mov rax,[rdi+0*8]
+	mul r15			
+	add r8,rax
+	adc r9,rdx
+
+	mov rax,[rdi+1*8]
+	mul r14			
+	mov r11,rbp
+	mov rbx,[rsi+2*8]
+	add r8,rax
+	adc r9,rdx
+	and r11,r8
+	shrd r8,r9,52
+	xor r9,r9
+	
+	;; c+=a.n[0 1 2] * b.n[2 1 0]
+	mov rax,[rdi+0*8]
+	mul rbx			
+	add r8,rax
+	adc r9,rdx
+
+	mov rax,[rdi+1*8]
+	mul r15			
+	add r8,rax
+	adc r9,rdx
+
+	mov rax,[rdi+2*8]
+	mul r14
+	mov r12,rbp		
+	mov rcx,[rsi+3*8]
+	add r8,rax
+	adc r9,rdx
+	and r12,r8		
+	shrd r8,r9,52
+	xor r9,r9		
+
+	;; c+=a.n[0 1 2 3] * b.n[3 2 1 0]
+	mov rax,[rdi+0*8]
+	mul rcx			
+	add r8,rax
+	adc r9,rdx
+
+	mov rax,[rdi+1*8]
+	mul rbx			
+	add r8,rax
+	adc r9,rdx
+
+	mov rax,[rdi+2*8]
+	mul r15			
+	add r8,rax
+	adc r9,rdx
+	
+	mov rax,[rdi+3*8]
+	mul r14			
+	mov r13,rbp             
+	mov rsi,[rsi+4*8]	; load b.n[4] and destroy pointer
+	add r8,rax
+	adc r9,rdx
+	and r13,r8
+
+	shrd r8,r9,52
+	xor r9,r9		
+
+
+	;; c+=a.n[0 1 2 3 4] * b.n[4 3 2 1 0]
+	mov rax,[rdi+0*8]
+	mul rsi
+	add r8,rax
+	adc r9,rdx
+
+	mov rax,[rdi+1*8]
+	mul rcx
+	add r8,rax
+	adc r9,rdx
+
+	mov rax,[rdi+2*8]
+	mul rbx			
+	add r8,rax
+	adc r9,rdx
+
+	mov rax,[rdi+3*8]
+	mul r15			
+	add r8,rax
+	adc r9,rdx
+
+	mov rax,[rdi+4*8]
+	mul r14			
+	mov r14,rbp             ; load modulus into t4 and destroy a.n[0]
+	add r8,rax
+	adc r9,rdx
+	and r14,r8
+	shrd r8,r9,52
+	xor r9,r9		
+
+	;; c+=a.n[1 2 3 4] * b.n[4 3 2 1]
+	mov rax,[rdi+1*8]
+	mul rsi
+	add r8,rax
+	adc r9,rdx
+
+	mov rax,[rdi+2*8]
+	mul rcx
+	add r8,rax
+	adc r9,rdx
+
+	mov rax,[rdi+3*8]
+	mul rbx
+	add r8,rax
+	adc r9,rdx
+
+	mov rax,[rdi+4*8]
+	mul r15
+	mov r15,rbp		
+	add r8,rax
+	adc r9,rdx
+
+	and r15,r8
+	shrd r8,r9,52
+	xor r9,r9		
+
+	;; c+=a.n[2 3 4] * b.n[4 3 2]
+	mov rax,[rdi+2*8]
+	mul rsi
+	add r8,rax
+	adc r9,rdx
+
+	mov rax,[rdi+3*8]
+	mul rcx
+	add r8,rax
+	adc r9,rdx
+
+	mov rax,[rdi+4*8]
+	mul rbx
+	mov rbx,rbp		
+	add r8,rax
+	adc r9,rdx
+
+	and rbx,r8		
+	shrd r8,r9,52
+	xor r9,r9		
+
+	;; c+=a.n[3 4] * b.n[4 3]
+	mov rax,[rdi+3*8]
+	mul rsi
+	add r8,rax
+	adc r9,rdx
+
+	mov rax,[rdi+4*8]
+	mul rcx
+	mov rcx,rbp		
+	add r8,rax
+	adc r9,rdx
+	and rcx,r8		
+	shrd r8,r9,52
+	xor r9,r9		
+
+	;; c+=a.n[4] * b.n[4]
+	mov rax,[rdi+4*8]
+	mul rsi
+	;; mov rbp,rbp		; modulus already there!
+	add r8,rax
+	adc r9,rdx
+	and rbp,r8 
+	shrd r8,r9,52
+	xor r9,r9		
+
+	mov rsi,r8		; load c into t9 and destroy b.n[4]
+
+	;; *******************************************************
+common_exit_norm:
+	mov rdi,01000003D10h	; load constant
+
+	mov rax,r15		; get t5
+	mul rdi
+	add rax,r10    		; +t0
+	adc rdx,0
+	mov r10,0FFFFFFFFFFFFFh ; modulus. Sadly, we ran out of registers!
+	mov r8,rax		; +c
+	and r10,rax
+	shrd r8,rdx,52
+	xor r9,r9
+
+	mov rax,rbx		; get t6
+	mul rdi
+	add rax,r11		; +t1
+	adc rdx,0
+	mov r11,0FFFFFFFFFFFFFh ; modulus
+	add r8,rax		; +c
+	adc r9,rdx
+	and r11,r8
+	shrd r8,r9,52
+	xor r9,r9
+
+	mov rax,rcx    		; get t7
+	mul rdi
+	add rax,r12		; +t2
+	adc rdx,0
+	pop rbx			; retrieve pointer to this.n	
+	mov r12,0FFFFFFFFFFFFFh ; modulus
+	add r8,rax		; +c
+	adc r9,rdx
+	and r12,r8
+	mov [rbx+2*8],r12	; mov into this.n[2]
+	shrd r8,r9,52
+	xor r9,r9
+	
+	mov rax,rbp    		; get t8
+	mul rdi
+	add rax,r13    		; +t3
+	adc rdx,0
+	mov r13,0FFFFFFFFFFFFFh ; modulus
+	add r8,rax		; +c
+	adc r9,rdx
+	and r13,r8
+	mov [rbx+3*8],r13	; -> this.n[3]
+	shrd r8,r9,52
+	xor r9,r9
+	
+	mov rax,rsi    		; get t9
+	mul rdi
+	add rax,r14    		; +t4
+	adc rdx,0
+	mov r14,0FFFFFFFFFFFFh	; !!!
+	add r8,rax		; +c
+	adc r9,rdx
+	and r14,r8
+	mov [rbx+4*8],r14	; -> this.n[4]
+	shrd r8,r9,48		; !!!
+	xor r9,r9
+	
+	mov rax,01000003D1h
+	mul r8		
+	add rax,r10
+	adc rdx,0
+	mov r10,0FFFFFFFFFFFFFh ; modulus
+	mov r8,rax
+	and rax,r10
+	shrd r8,rdx,52
+	mov [rbx+0*8],rax	; -> this.n[0]
+	add r8,r11
+	mov [rbx+1*8],r8	; -> this.n[1]
+
+	pop r15
+	pop r14
+	pop r13
+	pop r12
+	pop rbx
+	pop rbp
+	ret
+
+	
+	;;  PROC ExSetSquare
+	;;  Register Layout:
+	;;  INPUT: 	rdi	 = a.n
+	;; 	   	rsi  	 = this.a
+	;;  INTERNAL:	rdx:rax  = multiplication accumulator
+	;; 		r9:r8    = c
+	;; 		r10-r13  = t0-t3
+	;; 		r14	 = a.n[0] / t4
+	;; 		r15	 = a.n[1] / t5
+	;; 		rbx	 = a.n[2] / t6
+	;; 		rcx	 = a.n[3] / t7
+	;; 		rbp	 = 0FFFFFFFFFFFFFh / t8
+	;; 		rsi	 = a.n[4] / t9
+	GLOBAL secp256k1_fe_sqr_inner
+	ALIGN 32
+secp256k1_fe_sqr_inner:
+	push rbp
+	push rbx
+	push r12
+	push r13
+	push r14
+	push r15
+	push rsi
+	mov rbp,0FFFFFFFFFFFFFh
+	
+	;; c=a.n[0] * a.n[0]
+   	mov r14,[rdi+0*8]	; r14=a.n[0]
+	mov r10,rbp		; modulus 
+	mov rax,r14
+	mul rax
+	mov r15,[rdi+1*8]	; a.n[1]
+	add r14,r14		; r14=2*a.n[0]
+	mov r8,rax
+	and r10,rax		; only need lower qword
+	shrd r8,rdx,52
+	xor r9,r9
+
+	;; c+=2*a.n[0] * a.n[1]
+	mov rax,r14		; r14=2*a.n[0]
+	mul r15
+	mov rbx,[rdi+2*8]	; rbx=a.n[2]
+	mov r11,rbp 		; modulus
+	add r8,rax
+	adc r9,rdx
+	and r11,r8
+	shrd r8,r9,52
+	xor r9,r9
+	
+	;; c+=2*a.n[0]*a.n[2]+a.n[1]*a.n[1]
+	mov rax,r14
+	mul rbx
+	add r8,rax
+	adc r9,rdx
+
+	mov rax,r15
+	mov r12,rbp		; modulus
+	mul rax
+	mov rcx,[rdi+3*8]	; rcx=a.n[3]
+	add r15,r15		; r15=a.n[1]*2
+	add r8,rax
+	adc r9,rdx
+	and r12,r8		; only need lower dword
+	shrd r8,r9,52
+	xor r9,r9		
+
+	;; c+=2*a.n[0]*a.n[3]+2*a.n[1]*a.n[2]
+	mov rax,r14
+	mul rcx
+	add r8,rax
+	adc r9,rdx
+
+	mov rax,r15		; rax=2*a.n[1]
+	mov r13,rbp		; modulus
+	mul rbx
+	mov rsi,[rdi+4*8]	; rsi=a.n[4]
+	add r8,rax
+	adc r9,rdx
+	and r13,r8
+	shrd r8,r9,52
+	xor r9,r9		
+
+	;; c+=2*a.n[0]*a.n[4]+2*a.n[1]*a.n[3]+a.n[2]*a.n[2]
+	mov rax,r14		; last time we need 2*a.n[0]
+	mul rsi
+	add r8,rax
+	adc r9,rdx
+
+	mov rax,r15
+	mul rcx
+	mov r14,rbp		; modulus
+	add r8,rax
+	adc r9,rdx
+
+	mov rax,rbx
+	mul rax
+	add rbx,rbx		; rcx=2*a.n[2]
+	add r8,rax
+	adc r9,rdx
+	and r14,r8
+	shrd r8,r9,52
+	xor r9,r9		
+
+	;; c+=2*a.n[1]*a.n[4]+2*a.n[2]*a.n[3]
+	mov rax,r15		; last time we need 2*a.n[1]
+	mul rsi
+	add r8,rax
+	adc r9,rdx
+
+	mov rax,rbx
+	mul rcx
+	mov r15,rbp		; modulus
+	add r8,rax
+	adc r9,rdx
+	and r15,r8
+	shrd r8,r9,52
+	xor r9,r9		
+
+	;; c+=2*a.n[2]*a.n[4]+a.n[3]*a.n[3]
+	mov rax,rbx		; last time we need 2*a.n[2]
+	mul rsi
+	add r8,rax
+	adc r9,rdx
+
+	mov rax,rcx		; a.n[3]
+	mul rax
+	mov rbx,rbp		; modulus
+	add r8,rax
+	adc r9,rdx
+	and rbx,r8		; only need lower dword
+	lea rax,[2*rcx]
+	shrd r8,r9,52
+	xor r9,r9		
+
+	;; c+=2*a.n[3]*a.n[4]
+	mul rsi
+	mov rcx,rbp		; modulus
+	add r8,rax
+	adc r9,rdx
+	and rcx,r8		; only need lower dword
+	shrd r8,r9,52
+	xor r9,r9		
+
+	;; c+=a.n[4]*a.n[4]
+	mov rax,rsi
+	mul rax
+	;; mov rbp,rbp		; modulus is already there!
+	add r8,rax
+	adc r9,rdx
+	and rbp,r8 
+	shrd r8,r9,52
+	xor r9,r9		
+
+	mov rsi,r8
+
+	;; *******************************************************
+	jmp common_exit_norm
+	end
+
+	
diff --git a/secp256k1/field_gmp.h b/secp256k1/field_gmp.h
new file mode 100644
index 000000000..d51dea0af
--- /dev/null
+++ b/secp256k1/field_gmp.h
@@ -0,0 +1,16 @@
+// Copyright (c) 2013 Pieter Wuille
+// Distributed under the MIT/X11 software license, see the accompanying
+// file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
+#ifndef _SECP256K1_FIELD_REPR_
+#define _SECP256K1_FIELD_REPR_
+
+#include <gmp.h>
+
+#define FIELD_LIMBS ((256 + GMP_NUMB_BITS - 1) / GMP_NUMB_BITS)
+
+typedef struct {
+    mp_limb_t n[FIELD_LIMBS+1];
+} secp256k1_fe_t;
+
+#endif
diff --git a/secp256k1/group.h b/secp256k1/group.h
new file mode 100644
index 000000000..fc02a4249
--- /dev/null
+++ b/secp256k1/group.h
@@ -0,0 +1,110 @@
+// Copyright (c) 2013 Pieter Wuille
+// Distributed under the MIT/X11 software license, see the accompanying
+// file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
+#ifndef _SECP256K1_GROUP_
+#define _SECP256K1_GROUP_
+
+#include "num.h"
+#include "field.h"
+
+/** A group element of the secp256k1 curve, in affine coordinates. */
+typedef struct {
+    secp256k1_fe_t x;
+    secp256k1_fe_t y;
+    int infinity; // whether this represents the point at infinity
+} secp256k1_ge_t;
+
+/** A group element of the secp256k1 curve, in jacobian coordinates. */
+typedef struct {
+    secp256k1_fe_t x; // actual X: x/z^2
+    secp256k1_fe_t y; // actual Y: y/z^3
+    secp256k1_fe_t z;
+    int infinity; // whether this represents the point at infinity
+} secp256k1_gej_t;
+
+/** Global constants related to the group */
+typedef struct {
+    secp256k1_num_t order; // the order of the curve (= order of its generator)
+    secp256k1_num_t half_order; // half the order of the curve (= order of its generator)
+    secp256k1_ge_t g; // the generator point
+
+    // constants related to secp256k1's efficiently computable endomorphism
+    secp256k1_fe_t beta;
+    secp256k1_num_t lambda, a1b2, b1, a2;
+} secp256k1_ge_consts_t;
+
+static const secp256k1_ge_consts_t *secp256k1_ge_consts = NULL;
+
+/** Initialize the group module. */
+void static secp256k1_ge_start(void);
+
+/** De-initialize the group module. */
+void static secp256k1_ge_stop(void);
+
+/** Set a group element equal to the point at infinity */
+void static secp256k1_ge_set_infinity(secp256k1_ge_t *r);
+
+/** Set a group element equal to the point with given X and Y coordinates */
+void static secp256k1_ge_set_xy(secp256k1_ge_t *r, const secp256k1_fe_t *x, const secp256k1_fe_t *y);
+
+/** Set a group element (jacobian) equal to the point with given X coordinate, and given oddness for Y.
+    The result is not guaranteed to be valid. */
+void static secp256k1_ge_set_xo(secp256k1_ge_t *r, const secp256k1_fe_t *x, int odd);
+
+/** Check whether a group element is the point at infinity. */
+int  static secp256k1_ge_is_infinity(const secp256k1_ge_t *a);
+
+/** Check whether a group element is valid (i.e., on the curve). */
+int  static secp256k1_ge_is_valid(const secp256k1_ge_t *a);
+
+void static secp256k1_ge_neg(secp256k1_ge_t *r, const secp256k1_ge_t *a);
+
+/** Get a hex representation of a point. *rlen will be overwritten with the real length. */
+void static secp256k1_ge_get_hex(char *r, int *rlen, const secp256k1_ge_t *a);
+
+/** Set a group element equal to another which is given in jacobian coordinates */
+void static secp256k1_ge_set_gej(secp256k1_ge_t *r, secp256k1_gej_t *a);
+
+
+/** Set a group element (jacobian) equal to the point at infinity. */
+void static secp256k1_gej_set_infinity(secp256k1_gej_t *r);
+
+/** Set a group element (jacobian) equal to the point with given X and Y coordinates. */
+void static secp256k1_gej_set_xy(secp256k1_gej_t *r, const secp256k1_fe_t *x, const secp256k1_fe_t *y);
+
+/** Set a group element (jacobian) equal to another which is given in affine coordinates. */
+void static secp256k1_gej_set_ge(secp256k1_gej_t *r, const secp256k1_ge_t *a);
+
+/** Get the X coordinate of a group element (jacobian). */
+void static secp256k1_gej_get_x(secp256k1_fe_t *r, const secp256k1_gej_t *a);
+
+/** Set r equal to the inverse of a (i.e., mirrored around the X axis) */
+void static secp256k1_gej_neg(secp256k1_gej_t *r, const secp256k1_gej_t *a);
+
+/** Check whether a group element is the point at infinity. */
+int  static secp256k1_gej_is_infinity(const secp256k1_gej_t *a);
+
+/** Set r equal to the double of a. */
+void static secp256k1_gej_double(secp256k1_gej_t *r, const secp256k1_gej_t *a);
+
+/** Set r equal to the sum of a and b. */
+void static secp256k1_gej_add(secp256k1_gej_t *r, const secp256k1_gej_t *a, const secp256k1_gej_t *b);
+
+/** Set r equal to the sum of a and b (with b given in jacobian coordinates). This is more efficient
+    than secp256k1_gej_add. */
+void static secp256k1_gej_add_ge(secp256k1_gej_t *r, const secp256k1_gej_t *a, const secp256k1_ge_t *b);
+
+/** Get a hex representation of a point. *rlen will be overwritten with the real length. */
+void static secp256k1_gej_get_hex(char *r, int *rlen, const secp256k1_gej_t *a);
+
+#ifdef USE_ENDOMORPHISM
+/** Set r to be equal to lambda times a, where lambda is chosen in a way such that this is very fast. */
+void static secp256k1_gej_mul_lambda(secp256k1_gej_t *r, const secp256k1_gej_t *a);
+
+/** Find r1 and r2 such that r1+r2*lambda = a, and r1 and r2 are maximum 128 bits long (given that a is
+    not more than 256 bits). */
+void static secp256k1_gej_split_exp(secp256k1_num_t *r1, secp256k1_num_t *r2, const secp256k1_num_t *a);
+#endif
+
+#endif
diff --git a/secp256k1/impl/ecdsa.h b/secp256k1/impl/ecdsa.h
new file mode 100644
index 000000000..b001e263f
--- /dev/null
+++ b/secp256k1/impl/ecdsa.h
@@ -0,0 +1,307 @@
+// Copyright (c) 2013 Pieter Wuille
+// Distributed under the MIT/X11 software license, see the accompanying
+// file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
+#ifndef _SECP256K1_ECDSA_IMPL_H_
+#define _SECP256K1_ECDSA_IMPL_H_
+
+#include "../num.h"
+#include "../field.h"
+#include "../group.h"
+#include "../ecmult.h"
+#include "../ecdsa.h"
+
+void static secp256k1_ecdsa_sig_init(secp256k1_ecdsa_sig_t *r) {
+    secp256k1_num_init(&r->r);
+    secp256k1_num_init(&r->s);
+}
+
+void static secp256k1_ecdsa_sig_free(secp256k1_ecdsa_sig_t *r) {
+    secp256k1_num_free(&r->r);
+    secp256k1_num_free(&r->s);
+}
+
+int static secp256k1_ecdsa_pubkey_parse(secp256k1_ge_t *elem, const unsigned char *pub, int size) {
+    if (size == 33 && (pub[0] == 0x02 || pub[0] == 0x03)) {
+        secp256k1_fe_t x;
+        secp256k1_fe_set_b32(&x, pub+1);
+        secp256k1_ge_set_xo(elem, &x, pub[0] == 0x03);
+    } else if (size == 65 && (pub[0] == 0x04 || pub[0] == 0x06 || pub[0] == 0x07)) {
+        secp256k1_fe_t x, y;
+        secp256k1_fe_set_b32(&x, pub+1);
+        secp256k1_fe_set_b32(&y, pub+33);
+        secp256k1_ge_set_xy(elem, &x, &y);
+        if ((pub[0] == 0x06 || pub[0] == 0x07) && secp256k1_fe_is_odd(&y) != (pub[0] == 0x07))
+            return 0;
+    } else {
+        return 0;
+    }
+    return secp256k1_ge_is_valid(elem);
+}
+
+int static secp256k1_ecdsa_sig_parse(secp256k1_ecdsa_sig_t *r, const unsigned char *sig, int size) {
+    if (sig[0] != 0x30) return 0;
+    int lenr = sig[3];
+    if (5+lenr >= size) return 0;
+    int lens = sig[lenr+5];
+    if (sig[1] != lenr+lens+4) return 0;
+    if (lenr+lens+6 > size) return 0;
+    if (sig[2] != 0x02) return 0;
+    if (lenr == 0) return 0;
+    if (sig[lenr+4] != 0x02) return 0;
+    if (lens == 0) return 0;
+    secp256k1_num_set_bin(&r->r, sig+4, lenr);
+    secp256k1_num_set_bin(&r->s, sig+6+lenr, lens);
+    return 1;
+}
+
+int static secp256k1_ecdsa_sig_serialize(unsigned char *sig, int *size, const secp256k1_ecdsa_sig_t *a) {
+    int lenR = (secp256k1_num_bits(&a->r) + 7)/8;
+    if (lenR == 0 || secp256k1_num_get_bit(&a->r, lenR*8-1))
+        lenR++;
+    int lenS = (secp256k1_num_bits(&a->s) + 7)/8;
+    if (lenS == 0 || secp256k1_num_get_bit(&a->s, lenS*8-1))
+        lenS++;
+    if (*size < 6+lenS+lenR)
+        return 0;
+    *size = 6 + lenS + lenR;
+    sig[0] = 0x30;
+    sig[1] = 4 + lenS + lenR;
+    sig[2] = 0x02;
+    sig[3] = lenR;
+    secp256k1_num_get_bin(sig+4, lenR, &a->r);
+    sig[4+lenR] = 0x02;
+    sig[5+lenR] = lenS;
+    secp256k1_num_get_bin(sig+lenR+6, lenS, &a->s);
+    return 1;
+}
+
+int static secp256k1_ecdsa_sig_recompute(secp256k1_num_t *r2, const secp256k1_ecdsa_sig_t *sig, const secp256k1_ge_t *pubkey, const secp256k1_num_t *message) {
+    const secp256k1_ge_consts_t *c = secp256k1_ge_consts;
+
+    if (secp256k1_num_is_neg(&sig->r) || secp256k1_num_is_neg(&sig->s))
+        return 0;
+    if (secp256k1_num_is_zero(&sig->r) || secp256k1_num_is_zero(&sig->s))
+        return 0;
+    if (secp256k1_num_cmp(&sig->r, &c->order) >= 0 || secp256k1_num_cmp(&sig->s, &c->order) >= 0)
+        return 0;
+
+    int ret = 0;
+    secp256k1_num_t sn, u1, u2;
+    secp256k1_num_init(&sn);
+    secp256k1_num_init(&u1);
+    secp256k1_num_init(&u2);
+    secp256k1_num_mod_inverse(&sn, &sig->s, &c->order);
+    secp256k1_num_mod_mul(&u1, &sn, message, &c->order);
+    secp256k1_num_mod_mul(&u2, &sn, &sig->r, &c->order);
+    secp256k1_gej_t pubkeyj; secp256k1_gej_set_ge(&pubkeyj, pubkey);
+    secp256k1_gej_t pr; secp256k1_ecmult(&pr, &pubkeyj, &u2, &u1);
+    if (!secp256k1_gej_is_infinity(&pr)) {
+        secp256k1_fe_t xr; secp256k1_gej_get_x(&xr, &pr);
+        secp256k1_fe_normalize(&xr);
+        unsigned char xrb[32]; secp256k1_fe_get_b32(xrb, &xr);
+        secp256k1_num_set_bin(r2, xrb, 32);
+        secp256k1_num_mod(r2, &c->order);
+        ret = 1;
+    }
+    secp256k1_num_free(&sn);
+    secp256k1_num_free(&u1);
+    secp256k1_num_free(&u2);
+    return ret;
+}
+
+int static secp256k1_ecdsa_sig_recover(const secp256k1_ecdsa_sig_t *sig, secp256k1_ge_t *pubkey, const secp256k1_num_t *message, int recid) {
+    const secp256k1_ge_consts_t *c = secp256k1_ge_consts;
+
+    if (secp256k1_num_is_neg(&sig->r) || secp256k1_num_is_neg(&sig->s))
+        return 0;
+    if (secp256k1_num_is_zero(&sig->r) || secp256k1_num_is_zero(&sig->s))
+        return 0;
+    if (secp256k1_num_cmp(&sig->r, &c->order) >= 0 || secp256k1_num_cmp(&sig->s, &c->order) >= 0)
+        return 0;
+
+    secp256k1_num_t rx;
+    secp256k1_num_init(&rx);
+    secp256k1_num_copy(&rx, &sig->r);
+    if (recid & 2) {
+        secp256k1_num_add(&rx, &rx, &c->order);
+        if (secp256k1_num_cmp(&rx, &secp256k1_fe_consts->p) >= 0)
+            return 0;
+    }
+    unsigned char brx[32];
+    secp256k1_num_get_bin(brx, 32, &rx);
+    secp256k1_num_free(&rx);
+    secp256k1_fe_t fx;
+    secp256k1_fe_set_b32(&fx, brx);
+    secp256k1_ge_t x;
+    secp256k1_ge_set_xo(&x, &fx, recid & 1);
+    if (!secp256k1_ge_is_valid(&x))
+        return 0;
+    secp256k1_gej_t xj;
+    secp256k1_gej_set_ge(&xj, &x);
+    secp256k1_num_t rn, u1, u2;
+    secp256k1_num_init(&rn);
+    secp256k1_num_init(&u1);
+    secp256k1_num_init(&u2);
+    secp256k1_num_mod_inverse(&rn, &sig->r, &c->order);
+    secp256k1_num_mod_mul(&u1, &rn, message, &c->order);
+    secp256k1_num_sub(&u1, &c->order, &u1);
+    secp256k1_num_mod_mul(&u2, &rn, &sig->s, &c->order);
+    secp256k1_gej_t qj;
+    secp256k1_ecmult(&qj, &xj, &u2, &u1);
+    secp256k1_ge_set_gej(pubkey, &qj);
+    secp256k1_num_free(&rn);
+    secp256k1_num_free(&u1);
+    secp256k1_num_free(&u2);
+    return 1;
+}
+
+int static secp256k1_ecdsa_sig_verify(const secp256k1_ecdsa_sig_t *sig, const secp256k1_ge_t *pubkey, const secp256k1_num_t *message) {
+    secp256k1_num_t r2;
+    secp256k1_num_init(&r2);
+    int ret = 0;
+    ret = secp256k1_ecdsa_sig_recompute(&r2, sig, pubkey, message) && secp256k1_num_cmp(&sig->r, &r2) == 0;
+    secp256k1_num_free(&r2);
+    return ret;
+}
+
+int static secp256k1_ecdsa_sig_sign(secp256k1_ecdsa_sig_t *sig, const secp256k1_num_t *seckey, const secp256k1_num_t *message, const secp256k1_num_t *nonce, int *recid) {
+    const secp256k1_ge_consts_t *c = secp256k1_ge_consts;
+
+    secp256k1_gej_t rp;
+    secp256k1_ecmult_gen(&rp, nonce);
+    secp256k1_ge_t r;
+    secp256k1_ge_set_gej(&r, &rp);
+    unsigned char b[32];
+    secp256k1_fe_normalize(&r.x);
+    secp256k1_fe_normalize(&r.y);
+    secp256k1_fe_get_b32(b, &r.x);
+    secp256k1_num_set_bin(&sig->r, b, 32);
+    if (recid)
+        *recid = (secp256k1_num_cmp(&sig->r, &c->order) >= 0 ? 2 : 0) | (secp256k1_fe_is_odd(&r.y) ? 1 : 0);
+    secp256k1_num_mod(&sig->r, &c->order);
+    secp256k1_num_t n;
+    secp256k1_num_init(&n);
+    secp256k1_num_mod_mul(&n, &sig->r, seckey, &c->order);
+    secp256k1_num_add(&n, &n, message);
+    secp256k1_num_mod(&n, &c->order);
+    secp256k1_num_mod_inverse(&sig->s, nonce, &c->order);
+    secp256k1_num_mod_mul(&sig->s, &sig->s, &n, &c->order);
+    secp256k1_num_free(&n);
+    if (secp256k1_num_is_zero(&sig->s))
+        return 0;
+    if (secp256k1_num_cmp(&sig->s, &c->half_order) > 0) {
+        secp256k1_num_sub(&sig->s, &c->order, &sig->s);
+        if (recid)
+            *recid ^= 1;
+    }
+    return 1;
+}
+
+void static secp256k1_ecdsa_sig_set_rs(secp256k1_ecdsa_sig_t *sig, const secp256k1_num_t *r, const secp256k1_num_t *s) {
+    secp256k1_num_copy(&sig->r, r);
+    secp256k1_num_copy(&sig->s, s);
+}
+
+void static secp256k1_ecdsa_pubkey_serialize(secp256k1_ge_t *elem, unsigned char *pub, int *size, int compressed) {
+    secp256k1_fe_normalize(&elem->x);
+    secp256k1_fe_normalize(&elem->y);
+    secp256k1_fe_get_b32(&pub[1], &elem->x);
+    if (compressed) {
+        *size = 33;
+        pub[0] = 0x02 | (secp256k1_fe_is_odd(&elem->y) ? 0x01 : 0x00);
+    } else {
+        *size = 65;
+        pub[0] = 0x04;
+        secp256k1_fe_get_b32(&pub[33], &elem->y);
+    }
+}
+
+int static secp256k1_ecdsa_privkey_parse(secp256k1_num_t *key, const unsigned char *privkey, int privkeylen) {
+    const unsigned char *end = privkey + privkeylen;
+    // sequence header
+    if (end < privkey+1 || *privkey != 0x30)
+        return 0;
+    privkey++;
+    // sequence length constructor
+    int lenb = 0;
+    if (end < privkey+1 || !(*privkey & 0x80))
+        return 0;
+    lenb = *privkey & ~0x80; privkey++;
+    if (lenb < 1 || lenb > 2)
+        return 0;
+    if (end < privkey+lenb)
+        return 0;
+    // sequence length
+    int len = 0;
+    len = privkey[lenb-1] | (lenb > 1 ? privkey[lenb-2] << 8 : 0);
+    privkey += lenb;
+    if (end < privkey+len)
+        return 0;
+    // sequence element 0: version number (=1)
+    if (end < privkey+3 || privkey[0] != 0x02 || privkey[1] != 0x01 || privkey[2] != 0x01)
+        return 0;
+    privkey += 3;
+    // sequence element 1: octet string, up to 32 bytes
+    if (end < privkey+2 || privkey[0] != 0x04 || privkey[1] > 0x20 || end < privkey+2+privkey[1])
+        return 0;
+    secp256k1_num_set_bin(key, privkey+2, privkey[1]);
+    return 1;
+}
+
+int static secp256k1_ecdsa_privkey_serialize(unsigned char *privkey, int *privkeylen, const secp256k1_num_t *key, int compressed) {
+    secp256k1_gej_t rp;
+    secp256k1_ecmult_gen(&rp, key);
+    secp256k1_ge_t r;
+    secp256k1_ge_set_gej(&r, &rp);
+    if (compressed) {
+        static const unsigned char begin[] = {
+            0x30,0x81,0xD3,0x02,0x01,0x01,0x04,0x20
+        };
+        static const unsigned char middle[] = {
+            0xA0,0x81,0x85,0x30,0x81,0x82,0x02,0x01,0x01,0x30,0x2C,0x06,0x07,0x2A,0x86,0x48,
+            0xCE,0x3D,0x01,0x01,0x02,0x21,0x00,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,
+            0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,
+            0xFF,0xFF,0xFE,0xFF,0xFF,0xFC,0x2F,0x30,0x06,0x04,0x01,0x00,0x04,0x01,0x07,0x04,
+            0x21,0x02,0x79,0xBE,0x66,0x7E,0xF9,0xDC,0xBB,0xAC,0x55,0xA0,0x62,0x95,0xCE,0x87,
+            0x0B,0x07,0x02,0x9B,0xFC,0xDB,0x2D,0xCE,0x28,0xD9,0x59,0xF2,0x81,0x5B,0x16,0xF8,
+            0x17,0x98,0x02,0x21,0x00,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,
+            0xFF,0xFF,0xFF,0xFF,0xFE,0xBA,0xAE,0xDC,0xE6,0xAF,0x48,0xA0,0x3B,0xBF,0xD2,0x5E,
+            0x8C,0xD0,0x36,0x41,0x41,0x02,0x01,0x01,0xA1,0x24,0x03,0x22,0x00
+        };
+        unsigned char *ptr = privkey;
+        memcpy(ptr, begin, sizeof(begin)); ptr += sizeof(begin);
+        secp256k1_num_get_bin(ptr, 32, key); ptr += 32;
+        memcpy(ptr, middle, sizeof(middle)); ptr += sizeof(middle);
+        int pubkeylen = 0;
+        secp256k1_ecdsa_pubkey_serialize(&r, ptr, &pubkeylen, 1); ptr += pubkeylen;
+        *privkeylen = ptr - privkey;
+    } else {
+        static const unsigned char begin[] = {
+            0x30,0x82,0x01,0x13,0x02,0x01,0x01,0x04,0x20
+        };
+        static const unsigned char middle[] = {
+            0xA0,0x81,0xA5,0x30,0x81,0xA2,0x02,0x01,0x01,0x30,0x2C,0x06,0x07,0x2A,0x86,0x48,
+            0xCE,0x3D,0x01,0x01,0x02,0x21,0x00,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,
+            0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,
+            0xFF,0xFF,0xFE,0xFF,0xFF,0xFC,0x2F,0x30,0x06,0x04,0x01,0x00,0x04,0x01,0x07,0x04,
+            0x41,0x04,0x79,0xBE,0x66,0x7E,0xF9,0xDC,0xBB,0xAC,0x55,0xA0,0x62,0x95,0xCE,0x87,
+            0x0B,0x07,0x02,0x9B,0xFC,0xDB,0x2D,0xCE,0x28,0xD9,0x59,0xF2,0x81,0x5B,0x16,0xF8,
+            0x17,0x98,0x48,0x3A,0xDA,0x77,0x26,0xA3,0xC4,0x65,0x5D,0xA4,0xFB,0xFC,0x0E,0x11,
+            0x08,0xA8,0xFD,0x17,0xB4,0x48,0xA6,0x85,0x54,0x19,0x9C,0x47,0xD0,0x8F,0xFB,0x10,
+            0xD4,0xB8,0x02,0x21,0x00,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,
+            0xFF,0xFF,0xFF,0xFF,0xFE,0xBA,0xAE,0xDC,0xE6,0xAF,0x48,0xA0,0x3B,0xBF,0xD2,0x5E,
+            0x8C,0xD0,0x36,0x41,0x41,0x02,0x01,0x01,0xA1,0x44,0x03,0x42,0x00
+        };
+        unsigned char *ptr = privkey;
+        memcpy(ptr, begin, sizeof(begin)); ptr += sizeof(begin);
+        secp256k1_num_get_bin(ptr, 32, key); ptr += 32;
+        memcpy(ptr, middle, sizeof(middle)); ptr += sizeof(middle);
+        int pubkeylen = 0;
+        secp256k1_ecdsa_pubkey_serialize(&r, ptr, &pubkeylen, 0); ptr += pubkeylen;
+        *privkeylen = ptr - privkey;
+    }
+    return 1;
+}
+
+#endif
diff --git a/secp256k1/impl/ecmult.h b/secp256k1/impl/ecmult.h
new file mode 100644
index 000000000..c6711ac4c
--- /dev/null
+++ b/secp256k1/impl/ecmult.h
@@ -0,0 +1,259 @@
+// Copyright (c) 2013 Pieter Wuille
+// Distributed under the MIT/X11 software license, see the accompanying
+// file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
+#ifndef _SECP256K1_ECMULT_IMPL_H_
+#define _SECP256K1_ECMULT_IMPL_H_
+
+#include "../num.h"
+#include "../group.h"
+#include "../ecmult.h"
+
+// optimal for 128-bit and 256-bit exponents.
+#define WINDOW_A 5
+
+// larger numbers may result in slightly better performance, at the cost of
+// exponentially larger precomputed tables. WINDOW_G == 14 results in 640 KiB.
+#define WINDOW_G 14
+
+/** Fill a table 'pre' with precomputed odd multiples of a. W determines the size of the table.
+ *  pre will contains the values [1*a,3*a,5*a,...,(2^(w-1)-1)*a], so it needs place for
+ *  2^(w-2) entries.
+ *
+ *  There are two versions of this function:
+ *  - secp256k1_ecmult_precomp_wnaf_gej, which operates on group elements in jacobian notation,
+ *    fast to precompute, but slower to use in later additions.
+ *  - secp256k1_ecmult_precomp_wnaf_ge, which operates on group elements in affine notations,
+ *    (much) slower to precompute, but a bit faster to use in later additions.
+ *  To compute a*P + b*G, we use the jacobian version for P, and the affine version for G, as
+ *  G is constant, so it only needs to be done once in advance.
+ */
+void static secp256k1_ecmult_table_precomp_gej(secp256k1_gej_t *pre, const secp256k1_gej_t *a, int w) {
+    pre[0] = *a;
+    secp256k1_gej_t d; secp256k1_gej_double(&d, &pre[0]);
+    for (int i=1; i<(1 << (w-2)); i++)
+        secp256k1_gej_add(&pre[i], &d, &pre[i-1]);
+}
+
+void static secp256k1_ecmult_table_precomp_ge(secp256k1_ge_t *pre, const secp256k1_ge_t *a, int w) {
+    pre[0] = *a;
+    secp256k1_gej_t x; secp256k1_gej_set_ge(&x, a);
+    secp256k1_gej_t d; secp256k1_gej_double(&d, &x);
+    for (int i=1; i<(1 << (w-2)); i++) {
+        secp256k1_gej_add_ge(&x, &d, &pre[i-1]);
+        secp256k1_ge_set_gej(&pre[i], &x);
+    }
+}
+
+/** The number of entries a table with precomputed multiples needs to have. */
+#define ECMULT_TABLE_SIZE(w) (1 << ((w)-2))
+
+/** The following two macro retrieves a particular odd multiple from a table
+ *  of precomputed multiples. */
+#define ECMULT_TABLE_GET(r,pre,n,w,neg) do { \
+    assert(((n) & 1) == 1); \
+    assert((n) >= -((1 << ((w)-1)) - 1)); \
+    assert((n) <=  ((1 << ((w)-1)) - 1)); \
+    if ((n) > 0) \
+        *(r) = (pre)[((n)-1)/2]; \
+    else \
+        (neg)((r), &(pre)[(-(n)-1)/2]); \
+} while(0)
+
+#define ECMULT_TABLE_GET_GEJ(r,pre,n,w) ECMULT_TABLE_GET((r),(pre),(n),(w),secp256k1_gej_neg)
+#define ECMULT_TABLE_GET_GE(r,pre,n,w)  ECMULT_TABLE_GET((r),(pre),(n),(w),secp256k1_ge_neg)
+
+typedef struct {
+    secp256k1_ge_t pre_g[ECMULT_TABLE_SIZE(WINDOW_G)];    // odd multiples of the generator
+    secp256k1_ge_t pre_g_128[ECMULT_TABLE_SIZE(WINDOW_G)]; // odd multiples of 2^128*generator
+    secp256k1_ge_t prec[64][16]; // prec[j][i] = 16^j * (i+1) * G
+    secp256k1_ge_t fin; // -(sum(prec[j][0], j=0..63))
+} secp256k1_ecmult_consts_t;
+
+static const secp256k1_ecmult_consts_t *secp256k1_ecmult_consts = NULL;
+
+static void secp256k1_ecmult_start(void) {
+    if (secp256k1_ecmult_consts != NULL)
+        return;
+
+    secp256k1_ecmult_consts_t *ret = (secp256k1_ecmult_consts_t*)malloc(sizeof(secp256k1_ecmult_consts_t));
+    secp256k1_ecmult_consts = ret;
+
+    // get the generator
+    const secp256k1_ge_t *g = &secp256k1_ge_consts->g;
+
+    // calculate 2^128*generator
+    secp256k1_gej_t g_128j; secp256k1_gej_set_ge(&g_128j, g);
+    for (int i=0; i<128; i++)
+        secp256k1_gej_double(&g_128j, &g_128j);
+    secp256k1_ge_t g_128; secp256k1_ge_set_gej(&g_128, &g_128j);
+
+    // precompute the tables with odd multiples
+    secp256k1_ecmult_table_precomp_ge(ret->pre_g, g, WINDOW_G);
+    secp256k1_ecmult_table_precomp_ge(ret->pre_g_128, &g_128, WINDOW_G);
+
+    // compute prec and fin
+    secp256k1_gej_t gg; secp256k1_gej_set_ge(&gg, g);
+    secp256k1_ge_t ad = *g;
+    secp256k1_gej_t fn; secp256k1_gej_set_infinity(&fn);
+    for (int j=0; j<64; j++) {
+        secp256k1_ge_set_gej(&ret->prec[j][0], &gg);
+        secp256k1_gej_add(&fn, &fn, &gg);
+        for (int i=1; i<16; i++) {
+            secp256k1_gej_add_ge(&gg, &gg, &ad);
+            secp256k1_ge_set_gej(&ret->prec[j][i], &gg);
+        }
+        ad = ret->prec[j][15];
+    }
+    secp256k1_ge_set_gej(&ret->fin, &fn);
+    secp256k1_ge_neg(&ret->fin, &ret->fin);
+}
+
+static void secp256k1_ecmult_stop(void) {
+    if (secp256k1_ecmult_consts == NULL)
+        return;
+
+    secp256k1_ecmult_consts_t *c = (secp256k1_ecmult_consts_t*)secp256k1_ecmult_consts;
+    free(c);
+    secp256k1_ecmult_consts = NULL;
+}
+
+/** Convert a number to WNAF notation. The number becomes represented by sum(2^i * wnaf[i], i=0..bits),
+ *  with the following guarantees:
+ *  - each wnaf[i] is either 0, or an odd integer between -(1<<(w-1) - 1) and (1<<(w-1) - 1)
+ *  - two non-zero entries in wnaf are separated by at least w-1 zeroes.
+ *  - the index of the highest non-zero entry in wnaf (=return value-1) is at most bits, where
+ *    bits is the number of bits necessary to represent the absolute value of the input.
+ */
+static int secp256k1_ecmult_wnaf(int *wnaf, const secp256k1_num_t *a, int w) {
+    int ret = 0;
+    int zeroes = 0;
+    secp256k1_num_t x;
+    secp256k1_num_init(&x);
+    secp256k1_num_copy(&x, a);
+    int sign = 1;
+    if (secp256k1_num_is_neg(&x)) {
+        sign = -1;
+        secp256k1_num_negate(&x);
+    }
+    while (!secp256k1_num_is_zero(&x)) {
+        while (!secp256k1_num_is_odd(&x)) {
+            zeroes++;
+            secp256k1_num_shift(&x, 1);
+        }
+        int word = secp256k1_num_shift(&x, w);
+        while (zeroes) {
+            wnaf[ret++] = 0;
+            zeroes--;
+        }
+        if (word & (1 << (w-1))) {
+            secp256k1_num_inc(&x);
+            wnaf[ret++] = sign * (word - (1 << w));
+        } else {
+            wnaf[ret++] = sign * word;
+        }
+        zeroes = w-1;
+    }
+    secp256k1_num_free(&x);
+    return ret;
+}
+
+void static secp256k1_ecmult_gen(secp256k1_gej_t *r, const secp256k1_num_t *gn) {
+    secp256k1_num_t n;
+    secp256k1_num_init(&n);
+    secp256k1_num_copy(&n, gn);
+    const secp256k1_ecmult_consts_t *c = secp256k1_ecmult_consts;
+    secp256k1_gej_set_ge(r, &c->prec[0][secp256k1_num_shift(&n, 4)]);
+    for (int j=1; j<64; j++)
+        secp256k1_gej_add_ge(r, r, &c->prec[j][secp256k1_num_shift(&n, 4)]);
+    secp256k1_num_free(&n);
+    secp256k1_gej_add_ge(r, r, &c->fin);
+}
+
+void static secp256k1_ecmult(secp256k1_gej_t *r, const secp256k1_gej_t *a, const secp256k1_num_t *na, const secp256k1_num_t *ng) {
+    const secp256k1_ecmult_consts_t *c = secp256k1_ecmult_consts;
+
+#ifdef USE_ENDOMORPHISM
+    secp256k1_num_t na_1, na_lam;
+    secp256k1_num_init(&na_1);
+    secp256k1_num_init(&na_lam);
+    // split na into na_1 and na_lam (where na = na_1 + na_lam*lambda, and na_1 and na_lam are ~128 bit)
+    secp256k1_gej_split_exp(&na_1, &na_lam, na);
+
+    // build wnaf representation for na_1 and na_lam.
+    int wnaf_na_1[129];   int bits_na_1   = secp256k1_ecmult_wnaf(wnaf_na_1,   &na_1,   WINDOW_A);
+    int wnaf_na_lam[129]; int bits_na_lam = secp256k1_ecmult_wnaf(wnaf_na_lam, &na_lam, WINDOW_A);
+    int bits = bits_na_1;
+    if (bits_na_lam > bits) bits = bits_na_lam;
+
+    // calculate a_lam = a*lambda
+    secp256k1_gej_t a_lam; secp256k1_gej_mul_lambda(&a_lam, a);
+
+    // calculate odd multiples of a_lam
+    secp256k1_gej_t pre_a_lam[ECMULT_TABLE_SIZE(WINDOW_A)];
+    secp256k1_ecmult_table_precomp_gej(pre_a_lam, &a_lam, WINDOW_A);
+#else
+    // build wnaf representation for na.
+    int wnaf_na[257];     int bits_na     = secp256k1_ecmult_wnaf(wnaf_na,     na,      WINDOW_A);
+    int bits = bits_na;
+#endif
+
+    // calculate odd multiples of a
+    secp256k1_gej_t pre_a[ECMULT_TABLE_SIZE(WINDOW_A)];
+    secp256k1_ecmult_table_precomp_gej(pre_a, a, WINDOW_A);
+
+    // Splitted G factors.
+    secp256k1_num_t ng_1, ng_128;
+    secp256k1_num_init(&ng_1);
+    secp256k1_num_init(&ng_128);
+
+    // split ng into ng_1 and ng_128 (where gn = gn_1 + gn_128*2^128, and gn_1 and gn_128 are ~128 bit)
+    secp256k1_num_split(&ng_1, &ng_128, ng, 128);
+
+    // Build wnaf representation for ng_1 and ng_128
+    int wnaf_ng_1[129];   int bits_ng_1   = secp256k1_ecmult_wnaf(wnaf_ng_1,   &ng_1,   WINDOW_G);
+    int wnaf_ng_128[129]; int bits_ng_128 = secp256k1_ecmult_wnaf(wnaf_ng_128, &ng_128, WINDOW_G);
+    if (bits_ng_1 > bits) bits = bits_ng_1;
+    if (bits_ng_128 > bits) bits = bits_ng_128;
+
+    secp256k1_gej_set_infinity(r);
+    secp256k1_gej_t tmpj;
+    secp256k1_ge_t tmpa;
+
+    for (int i=bits-1; i>=0; i--) {
+        secp256k1_gej_double(r, r);
+        int n;
+#ifdef USE_ENDOMORPHISM
+        if (i < bits_na_1 && (n = wnaf_na_1[i])) {
+            ECMULT_TABLE_GET_GEJ(&tmpj, pre_a, n, WINDOW_A);
+            secp256k1_gej_add(r, r, &tmpj);
+        }
+        if (i < bits_na_lam && (n = wnaf_na_lam[i])) {
+            ECMULT_TABLE_GET_GEJ(&tmpj, pre_a_lam, n, WINDOW_A);
+            secp256k1_gej_add(r, r, &tmpj);
+        }
+#else
+        if (i < bits_na && (n = wnaf_na[i])) {
+            ECMULT_TABLE_GET_GEJ(&tmpj, pre_a, n, WINDOW_A);
+            secp256k1_gej_add(r, r, &tmpj);
+        }
+#endif
+        if (i < bits_ng_1 && (n = wnaf_ng_1[i])) {
+            ECMULT_TABLE_GET_GE(&tmpa, c->pre_g, n, WINDOW_G);
+            secp256k1_gej_add_ge(r, r, &tmpa);
+        }
+        if (i < bits_ng_128 && (n = wnaf_ng_128[i])) {
+            ECMULT_TABLE_GET_GE(&tmpa, c->pre_g_128, n, WINDOW_G);
+            secp256k1_gej_add_ge(r, r, &tmpa);
+        }
+    }
+
+#ifdef USE_ENDOMORPHISM
+    secp256k1_num_free(&na_1);
+    secp256k1_num_free(&na_lam);
+#endif
+    secp256k1_num_free(&ng_1);
+    secp256k1_num_free(&ng_128);
+}
+
+#endif
diff --git a/secp256k1/impl/field.h b/secp256k1/impl/field.h
new file mode 100644
index 000000000..c43188adc
--- /dev/null
+++ b/secp256k1/impl/field.h
@@ -0,0 +1,173 @@
+// Copyright (c) 2013 Pieter Wuille
+// Distributed under the MIT/X11 software license, see the accompanying
+// file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
+#ifndef _SECP256K1_FIELD_IMPL_H_
+#define _SECP256K1_FIELD_IMPL_H_
+
+#if defined(USE_FIELD_GMP)
+#include "field_gmp.h"
+#elif defined(USE_FIELD_10X26)
+#include "field_10x26.h"
+#elif defined(USE_FIELD_5X52)
+#include "field_5x52.h"
+#else
+#error "Please select field implementation"
+#endif
+
+void static secp256k1_fe_get_hex(char *r, int *rlen, const secp256k1_fe_t *a) {
+    if (*rlen < 65) {
+        *rlen = 65;
+        return;
+    }
+    *rlen = 65;
+    unsigned char tmp[32];
+    secp256k1_fe_t b = *a;
+    secp256k1_fe_normalize(&b);
+    secp256k1_fe_get_b32(tmp, &b);
+    for (int i=0; i<32; i++) {
+        static const char *c = "0123456789ABCDEF";
+        r[2*i]   = c[(tmp[i] >> 4) & 0xF];
+        r[2*i+1] = c[(tmp[i]) & 0xF];
+    }
+    r[64] = 0x00;
+}
+
+void static secp256k1_fe_set_hex(secp256k1_fe_t *r, const char *a, int alen) {
+    unsigned char tmp[32] = {};
+    static const int cvt[256] = {0, 0, 0, 0, 0, 0, 0,0,0,0,0,0,0,0,0,0,
+                                 0, 0, 0, 0, 0, 0, 0,0,0,0,0,0,0,0,0,0,
+                                 0, 0, 0, 0, 0, 0, 0,0,0,0,0,0,0,0,0,0,
+                                 0, 1, 2, 3, 4, 5, 6,7,8,9,0,0,0,0,0,0,
+                                 0,10,11,12,13,14,15,0,0,0,0,0,0,0,0,0,
+                                 0, 0, 0, 0, 0, 0, 0,0,0,0,0,0,0,0,0,0,
+                                 0,10,11,12,13,14,15,0,0,0,0,0,0,0,0,0,
+                                 0, 0, 0, 0, 0, 0, 0,0,0,0,0,0,0,0,0,0,
+                                 0, 0, 0, 0, 0, 0, 0,0,0,0,0,0,0,0,0,0,
+                                 0, 0, 0, 0, 0, 0, 0,0,0,0,0,0,0,0,0,0,
+                                 0, 0, 0, 0, 0, 0, 0,0,0,0,0,0,0,0,0,0,
+                                 0, 0, 0, 0, 0, 0, 0,0,0,0,0,0,0,0,0,0,
+                                 0, 0, 0, 0, 0, 0, 0,0,0,0,0,0,0,0,0,0,
+                                 0, 0, 0, 0, 0, 0, 0,0,0,0,0,0,0,0,0,0,
+                                 0, 0, 0, 0, 0, 0, 0,0,0,0,0,0,0,0,0,0,
+                                 0, 0, 0, 0, 0, 0, 0,0,0,0,0,0,0,0,0,0};
+    for (int i=0; i<32; i++) {
+        if (alen > i*2)
+            tmp[32 - alen/2 + i] = (cvt[(unsigned char)a[2*i]] << 4) + cvt[(unsigned char)a[2*i+1]];
+    }
+    secp256k1_fe_set_b32(r, tmp);
+}
+
+void static secp256k1_fe_sqrt(secp256k1_fe_t *r, const secp256k1_fe_t *a) {
+    // calculate a^p, with p={15,780,1022,1023}
+    secp256k1_fe_t a2; secp256k1_fe_sqr(&a2, a);
+    secp256k1_fe_t a3; secp256k1_fe_mul(&a3, &a2, a);
+    secp256k1_fe_t a6; secp256k1_fe_sqr(&a6, &a3);
+    secp256k1_fe_t a12; secp256k1_fe_sqr(&a12, &a6);
+    secp256k1_fe_t a15; secp256k1_fe_mul(&a15, &a12, &a3);
+    secp256k1_fe_t a30; secp256k1_fe_sqr(&a30, &a15);
+    secp256k1_fe_t a60; secp256k1_fe_sqr(&a60, &a30);
+    secp256k1_fe_t a120; secp256k1_fe_sqr(&a120, &a60);
+    secp256k1_fe_t a240; secp256k1_fe_sqr(&a240, &a120);
+    secp256k1_fe_t a255; secp256k1_fe_mul(&a255, &a240, &a15);
+    secp256k1_fe_t a510; secp256k1_fe_sqr(&a510, &a255);
+    secp256k1_fe_t a750; secp256k1_fe_mul(&a750, &a510, &a240);
+    secp256k1_fe_t a780; secp256k1_fe_mul(&a780, &a750, &a30);
+    secp256k1_fe_t a1020; secp256k1_fe_sqr(&a1020, &a510);
+    secp256k1_fe_t a1022; secp256k1_fe_mul(&a1022, &a1020, &a2);
+    secp256k1_fe_t a1023; secp256k1_fe_mul(&a1023, &a1022, a);
+    secp256k1_fe_t x = a15;
+    for (int i=0; i<21; i++) {
+        for (int j=0; j<10; j++) secp256k1_fe_sqr(&x, &x);
+        secp256k1_fe_mul(&x, &x, &a1023);
+    }
+    for (int j=0; j<10; j++) secp256k1_fe_sqr(&x, &x);
+    secp256k1_fe_mul(&x, &x, &a1022);
+    for (int i=0; i<2; i++) {
+        for (int j=0; j<10; j++) secp256k1_fe_sqr(&x, &x);
+        secp256k1_fe_mul(&x, &x, &a1023);
+    }
+    for (int j=0; j<10; j++) secp256k1_fe_sqr(&x, &x);
+    secp256k1_fe_mul(r, &x, &a780);
+}
+
+void static secp256k1_fe_inv(secp256k1_fe_t *r, const secp256k1_fe_t *a) {
+    // calculate a^p, with p={45,63,1019,1023}
+    secp256k1_fe_t a2; secp256k1_fe_sqr(&a2, a);
+    secp256k1_fe_t a3; secp256k1_fe_mul(&a3, &a2, a);
+    secp256k1_fe_t a4; secp256k1_fe_sqr(&a4, &a2);
+    secp256k1_fe_t a5; secp256k1_fe_mul(&a5, &a4, a);
+    secp256k1_fe_t a10; secp256k1_fe_sqr(&a10, &a5);
+    secp256k1_fe_t a11; secp256k1_fe_mul(&a11, &a10, a);
+    secp256k1_fe_t a21; secp256k1_fe_mul(&a21, &a11, &a10);
+    secp256k1_fe_t a42; secp256k1_fe_sqr(&a42, &a21);
+    secp256k1_fe_t a45; secp256k1_fe_mul(&a45, &a42, &a3);
+    secp256k1_fe_t a63; secp256k1_fe_mul(&a63, &a42, &a21);
+    secp256k1_fe_t a126; secp256k1_fe_sqr(&a126, &a63);
+    secp256k1_fe_t a252; secp256k1_fe_sqr(&a252, &a126);
+    secp256k1_fe_t a504; secp256k1_fe_sqr(&a504, &a252);
+    secp256k1_fe_t a1008; secp256k1_fe_sqr(&a1008, &a504);
+    secp256k1_fe_t a1019; secp256k1_fe_mul(&a1019, &a1008, &a11);
+    secp256k1_fe_t a1023; secp256k1_fe_mul(&a1023, &a1019, &a4);
+    secp256k1_fe_t x = a63;
+    for (int i=0; i<21; i++) {
+        for (int j=0; j<10; j++) secp256k1_fe_sqr(&x, &x);
+        secp256k1_fe_mul(&x, &x, &a1023);
+    }
+    for (int j=0; j<10; j++) secp256k1_fe_sqr(&x, &x);
+    secp256k1_fe_mul(&x, &x, &a1019);
+    for (int i=0; i<2; i++) {
+        for (int j=0; j<10; j++) secp256k1_fe_sqr(&x, &x);
+        secp256k1_fe_mul(&x, &x, &a1023);
+    }
+    for (int j=0; j<10; j++) secp256k1_fe_sqr(&x, &x);
+    secp256k1_fe_mul(r, &x, &a45);
+}
+
+void static secp256k1_fe_inv_var(secp256k1_fe_t *r, const secp256k1_fe_t *a) {
+#if defined(USE_FIELD_INV_BUILTIN)
+    secp256k1_fe_inv(r, a);
+#elif defined(USE_FIELD_INV_NUM)
+    unsigned char b[32];
+    secp256k1_fe_t c = *a;
+    secp256k1_fe_normalize(&c);
+    secp256k1_fe_get_b32(b, &c);
+    secp256k1_num_t n; 
+    secp256k1_num_init(&n);
+    secp256k1_num_set_bin(&n, b, 32);
+    secp256k1_num_mod_inverse(&n, &n, &secp256k1_fe_consts->p);
+    secp256k1_num_get_bin(b, 32, &n);
+    secp256k1_num_free(&n);
+    secp256k1_fe_set_b32(r, b);
+#else
+#error "Please select field inverse implementation"
+#endif
+}
+
+void static secp256k1_fe_start(void) {
+    static const unsigned char secp256k1_fe_consts_p[] = {
+        0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,
+        0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,
+        0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,
+        0xFF,0xFF,0xFF,0xFE,0xFF,0xFF,0xFC,0x2F
+    };
+    if (secp256k1_fe_consts == NULL) {
+        secp256k1_fe_inner_start();
+        secp256k1_fe_consts_t *ret = (secp256k1_fe_consts_t*)malloc(sizeof(secp256k1_fe_consts_t));
+        secp256k1_num_init(&ret->p);
+        secp256k1_num_set_bin(&ret->p, secp256k1_fe_consts_p, sizeof(secp256k1_fe_consts_p));
+        secp256k1_fe_consts = ret;
+    }
+}
+
+void static secp256k1_fe_stop(void) {
+    if (secp256k1_fe_consts != NULL) {
+        secp256k1_fe_consts_t *c = (secp256k1_fe_consts_t*)secp256k1_fe_consts;
+        secp256k1_num_free(&c->p);
+        free((void*)c);
+        secp256k1_fe_consts = NULL;
+        secp256k1_fe_inner_stop();
+    }
+}
+
+#endif
diff --git a/secp256k1/impl/field_10x26.h b/secp256k1/impl/field_10x26.h
new file mode 100644
index 000000000..449769254
--- /dev/null
+++ b/secp256k1/impl/field_10x26.h
@@ -0,0 +1,487 @@
+// Copyright (c) 2013 Pieter Wuille
+// Distributed under the MIT/X11 software license, see the accompanying
+// file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
+#ifndef _SECP256K1_FIELD_REPR_IMPL_H_
+#define _SECP256K1_FIELD_REPR_IMPL_H_
+
+#include <stdio.h>
+#include <assert.h>
+#include <string.h>
+#include "../num.h"
+#include "../field.h"
+
+void static secp256k1_fe_inner_start(void) {}
+void static secp256k1_fe_inner_stop(void) {}
+
+void static secp256k1_fe_normalize(secp256k1_fe_t *r) {
+//    fog("normalize in: ", r);
+    uint32_t c;
+    c = r->n[0];
+    uint32_t t0 = c & 0x3FFFFFFUL;
+    c = (c >> 26) + r->n[1];
+    uint32_t t1 = c & 0x3FFFFFFUL;
+    c = (c >> 26) + r->n[2];
+    uint32_t t2 = c & 0x3FFFFFFUL;
+    c = (c >> 26) + r->n[3];
+    uint32_t t3 = c & 0x3FFFFFFUL;
+    c = (c >> 26) + r->n[4];
+    uint32_t t4 = c & 0x3FFFFFFUL;
+    c = (c >> 26) + r->n[5];
+    uint32_t t5 = c & 0x3FFFFFFUL;
+    c = (c >> 26) + r->n[6];
+    uint32_t t6 = c & 0x3FFFFFFUL;
+    c = (c >> 26) + r->n[7];
+    uint32_t t7 = c & 0x3FFFFFFUL;
+    c = (c >> 26) + r->n[8];
+    uint32_t t8 = c & 0x3FFFFFFUL;
+    c = (c >> 26) + r->n[9];
+    uint32_t t9 = c & 0x03FFFFFUL;
+    c >>= 22;
+/*    r->n[0] = t0; r->n[1] = t1; r->n[2] = t2; r->n[3] = t3; r->n[4] = t4;
+    r->n[5] = t5; r->n[6] = t6; r->n[7] = t7; r->n[8] = t8; r->n[9] = t9;
+    fog("         tm1: ", r);
+    fprintf(stderr, "out c= %08lx\n", (unsigned long)c);*/
+
+    // The following code will not modify the t's if c is initially 0.
+    uint32_t d = c * 0x3D1UL + t0;
+    t0 = d & 0x3FFFFFFULL;
+    d = (d >> 26) + t1 + c*0x40;
+    t1 = d & 0x3FFFFFFULL;
+    d = (d >> 26) + t2;
+    t2 = d & 0x3FFFFFFULL;
+    d = (d >> 26) + t3;
+    t3 = d & 0x3FFFFFFULL;
+    d = (d >> 26) + t4;
+    t4 = d & 0x3FFFFFFULL;
+    d = (d >> 26) + t5;
+    t5 = d & 0x3FFFFFFULL;
+    d = (d >> 26) + t6;
+    t6 = d & 0x3FFFFFFULL;
+    d = (d >> 26) + t7;
+    t7 = d & 0x3FFFFFFULL;
+    d = (d >> 26) + t8;
+    t8 = d & 0x3FFFFFFULL;
+    d = (d >> 26) + t9;
+    t9 = d & 0x03FFFFFULL;
+    assert((d >> 22) == 0);
+/*    r->n[0] = t0; r->n[1] = t1; r->n[2] = t2; r->n[3] = t3; r->n[4] = t4;
+    r->n[5] = t5; r->n[6] = t6; r->n[7] = t7; r->n[8] = t8; r->n[9] = t9;
+    fog("         tm2: ", r); */
+
+    // Subtract p if result >= p
+    uint64_t low = ((uint64_t)t1 << 26) | t0;
+    uint64_t mask = -(int64_t)((t9 < 0x03FFFFFUL) | (t8 < 0x3FFFFFFUL) | (t7 < 0x3FFFFFFUL) | (t6 < 0x3FFFFFFUL) | (t5 < 0x3FFFFFFUL) | (t4 < 0x3FFFFFFUL) | (t3 < 0x3FFFFFFUL) | (t2 < 0x3FFFFFFUL) | (low < 0xFFFFEFFFFFC2FULL));
+    t9 &= mask;
+    t8 &= mask;
+    t7 &= mask;
+    t6 &= mask;
+    t5 &= mask;
+    t4 &= mask;
+    t3 &= mask;
+    t2 &= mask;
+    low -= (~mask & 0xFFFFEFFFFFC2FULL);
+
+    // push internal variables back
+    r->n[0] = low & 0x3FFFFFFUL; r->n[1] = (low >> 26) & 0x3FFFFFFUL; r->n[2] = t2; r->n[3] = t3; r->n[4] = t4;
+    r->n[5] = t5; r->n[6] = t6; r->n[7] = t7; r->n[8] = t8; r->n[9] = t9;
+/*    fog("         out: ", r);*/
+
+#ifdef VERIFY
+    r->magnitude = 1;
+    r->normalized = 1;
+#endif
+}
+
+void static inline secp256k1_fe_set_int(secp256k1_fe_t *r, int a) {
+    r->n[0] = a;
+    r->n[1] = r->n[2] = r->n[3] = r->n[4] = r->n[5] = r->n[6] = r->n[7] = r->n[8] = r->n[9] = 0;
+#ifdef VERIFY
+    r->magnitude = 1;
+    r->normalized = 1;
+#endif
+}
+
+// TODO: not constant time!
+int static inline secp256k1_fe_is_zero(const secp256k1_fe_t *a) {
+#ifdef VERIFY
+    assert(a->normalized);
+#endif
+    return (a->n[0] == 0 && a->n[1] == 0 && a->n[2] == 0 && a->n[3] == 0 && a->n[4] == 0 && a->n[5] == 0 && a->n[6] == 0 && a->n[7] == 0 && a->n[8] == 0 && a->n[9] == 0);
+}
+
+int static inline secp256k1_fe_is_odd(const secp256k1_fe_t *a) {
+#ifdef VERIFY
+    assert(a->normalized);
+#endif
+    return a->n[0] & 1;
+}
+
+// TODO: not constant time!
+int static inline secp256k1_fe_equal(const secp256k1_fe_t *a, const secp256k1_fe_t *b) {
+#ifdef VERIFY
+    assert(a->normalized);
+    assert(b->normalized);
+#endif
+    return (a->n[0] == b->n[0] && a->n[1] == b->n[1] && a->n[2] == b->n[2] && a->n[3] == b->n[3] && a->n[4] == b->n[4] &&
+            a->n[5] == b->n[5] && a->n[6] == b->n[6] && a->n[7] == b->n[7] && a->n[8] == b->n[8] && a->n[9] == b->n[9]);
+}
+
+void static secp256k1_fe_set_b32(secp256k1_fe_t *r, const unsigned char *a) {
+    r->n[0] = r->n[1] = r->n[2] = r->n[3] = r->n[4] = 0;
+    r->n[5] = r->n[6] = r->n[7] = r->n[8] = r->n[9] = 0;
+    for (int i=0; i<32; i++) {
+        for (int j=0; j<4; j++) {
+            int limb = (8*i+2*j)/26;
+            int shift = (8*i+2*j)%26;
+            r->n[limb] |= (uint32_t)((a[31-i] >> (2*j)) & 0x3) << shift;
+        }
+    }
+#ifdef VERIFY
+    r->magnitude = 1;
+    r->normalized = 1;
+#endif
+}
+
+/** Convert a field element to a 32-byte big endian value. Requires the input to be normalized */
+void static secp256k1_fe_get_b32(unsigned char *r, const secp256k1_fe_t *a) {
+#ifdef VERIFY
+    assert(a->normalized);
+#endif
+    for (int i=0; i<32; i++) {
+        int c = 0;
+        for (int j=0; j<4; j++) {
+            int limb = (8*i+2*j)/26;
+            int shift = (8*i+2*j)%26;
+            c |= ((a->n[limb] >> shift) & 0x3) << (2 * j);
+        }
+        r[31-i] = c;
+    }
+}
+
+void static inline secp256k1_fe_negate(secp256k1_fe_t *r, const secp256k1_fe_t *a, int m) {
+#ifdef VERIFY
+    assert(a->magnitude <= m);
+    r->magnitude = m + 1;
+    r->normalized = 0;
+#endif
+    r->n[0] = 0x3FFFC2FUL * (m + 1) - a->n[0];
+    r->n[1] = 0x3FFFFBFUL * (m + 1) - a->n[1];
+    r->n[2] = 0x3FFFFFFUL * (m + 1) - a->n[2];
+    r->n[3] = 0x3FFFFFFUL * (m + 1) - a->n[3];
+    r->n[4] = 0x3FFFFFFUL * (m + 1) - a->n[4];
+    r->n[5] = 0x3FFFFFFUL * (m + 1) - a->n[5];
+    r->n[6] = 0x3FFFFFFUL * (m + 1) - a->n[6];
+    r->n[7] = 0x3FFFFFFUL * (m + 1) - a->n[7];
+    r->n[8] = 0x3FFFFFFUL * (m + 1) - a->n[8];
+    r->n[9] = 0x03FFFFFUL * (m + 1) - a->n[9];
+}
+
+void static inline secp256k1_fe_mul_int(secp256k1_fe_t *r, int a) {
+#ifdef VERIFY
+    r->magnitude *= a;
+    r->normalized = 0;
+#endif
+    r->n[0] *= a;
+    r->n[1] *= a;
+    r->n[2] *= a;
+    r->n[3] *= a;
+    r->n[4] *= a;
+    r->n[5] *= a;
+    r->n[6] *= a;
+    r->n[7] *= a;
+    r->n[8] *= a;
+    r->n[9] *= a;
+}
+
+void static inline secp256k1_fe_add(secp256k1_fe_t *r, const secp256k1_fe_t *a) {
+#ifdef VERIFY
+    r->magnitude += a->magnitude;
+    r->normalized = 0;
+#endif
+    r->n[0] += a->n[0];
+    r->n[1] += a->n[1];
+    r->n[2] += a->n[2];
+    r->n[3] += a->n[3];
+    r->n[4] += a->n[4];
+    r->n[5] += a->n[5];
+    r->n[6] += a->n[6];
+    r->n[7] += a->n[7];
+    r->n[8] += a->n[8];
+    r->n[9] += a->n[9];
+}
+
+void static inline secp256k1_fe_mul_inner(const uint32_t *a, const uint32_t *b, uint32_t *r) {
+    uint64_t c = (uint64_t)a[0] * b[0];
+    uint32_t t0 = c & 0x3FFFFFFUL; c = c >> 26;
+    c = c + (uint64_t)a[0] * b[1] +
+            (uint64_t)a[1] * b[0];
+    uint32_t t1 = c & 0x3FFFFFFUL; c = c >> 26;
+    c = c + (uint64_t)a[0] * b[2] +
+            (uint64_t)a[1] * b[1] +
+            (uint64_t)a[2] * b[0];
+    uint32_t t2 = c & 0x3FFFFFFUL; c = c >> 26;
+    c = c + (uint64_t)a[0] * b[3] +
+            (uint64_t)a[1] * b[2] +
+            (uint64_t)a[2] * b[1] +
+            (uint64_t)a[3] * b[0];
+    uint32_t t3 = c & 0x3FFFFFFUL; c = c >> 26;
+    c = c + (uint64_t)a[0] * b[4] +
+            (uint64_t)a[1] * b[3] +
+            (uint64_t)a[2] * b[2] +
+            (uint64_t)a[3] * b[1] +
+            (uint64_t)a[4] * b[0];
+    uint32_t t4 = c & 0x3FFFFFFUL; c = c >> 26;
+    c = c + (uint64_t)a[0] * b[5] +
+            (uint64_t)a[1] * b[4] +
+            (uint64_t)a[2] * b[3] +
+            (uint64_t)a[3] * b[2] +
+            (uint64_t)a[4] * b[1] +
+            (uint64_t)a[5] * b[0];
+    uint32_t t5 = c & 0x3FFFFFFUL; c = c >> 26;
+    c = c + (uint64_t)a[0] * b[6] +
+            (uint64_t)a[1] * b[5] +
+            (uint64_t)a[2] * b[4] +
+            (uint64_t)a[3] * b[3] +
+            (uint64_t)a[4] * b[2] +
+            (uint64_t)a[5] * b[1] +
+            (uint64_t)a[6] * b[0];
+    uint32_t t6 = c & 0x3FFFFFFUL; c = c >> 26;
+    c = c + (uint64_t)a[0] * b[7] +
+            (uint64_t)a[1] * b[6] +
+            (uint64_t)a[2] * b[5] +
+            (uint64_t)a[3] * b[4] +
+            (uint64_t)a[4] * b[3] +
+            (uint64_t)a[5] * b[2] +
+            (uint64_t)a[6] * b[1] +
+            (uint64_t)a[7] * b[0];
+    uint32_t t7 = c & 0x3FFFFFFUL; c = c >> 26;
+    c = c + (uint64_t)a[0] * b[8] +
+            (uint64_t)a[1] * b[7] +
+            (uint64_t)a[2] * b[6] +
+            (uint64_t)a[3] * b[5] +
+            (uint64_t)a[4] * b[4] +
+            (uint64_t)a[5] * b[3] +
+            (uint64_t)a[6] * b[2] +
+            (uint64_t)a[7] * b[1] +
+            (uint64_t)a[8] * b[0];
+    uint32_t t8 = c & 0x3FFFFFFUL; c = c >> 26;
+    c = c + (uint64_t)a[0] * b[9] +
+            (uint64_t)a[1] * b[8] +
+            (uint64_t)a[2] * b[7] +
+            (uint64_t)a[3] * b[6] +
+            (uint64_t)a[4] * b[5] +
+            (uint64_t)a[5] * b[4] +
+            (uint64_t)a[6] * b[3] +
+            (uint64_t)a[7] * b[2] +
+            (uint64_t)a[8] * b[1] +
+            (uint64_t)a[9] * b[0];
+    uint32_t t9 = c & 0x3FFFFFFUL; c = c >> 26;
+    c = c + (uint64_t)a[1] * b[9] +
+            (uint64_t)a[2] * b[8] +
+            (uint64_t)a[3] * b[7] +
+            (uint64_t)a[4] * b[6] +
+            (uint64_t)a[5] * b[5] +
+            (uint64_t)a[6] * b[4] +
+            (uint64_t)a[7] * b[3] +
+            (uint64_t)a[8] * b[2] +
+            (uint64_t)a[9] * b[1];
+    uint32_t t10 = c & 0x3FFFFFFUL; c = c >> 26;
+    c = c + (uint64_t)a[2] * b[9] +
+            (uint64_t)a[3] * b[8] +
+            (uint64_t)a[4] * b[7] +
+            (uint64_t)a[5] * b[6] +
+            (uint64_t)a[6] * b[5] +
+            (uint64_t)a[7] * b[4] +
+            (uint64_t)a[8] * b[3] +
+            (uint64_t)a[9] * b[2];
+    uint32_t t11 = c & 0x3FFFFFFUL; c = c >> 26;
+    c = c + (uint64_t)a[3] * b[9] +
+            (uint64_t)a[4] * b[8] +
+            (uint64_t)a[5] * b[7] +
+            (uint64_t)a[6] * b[6] +
+            (uint64_t)a[7] * b[5] +
+            (uint64_t)a[8] * b[4] +
+            (uint64_t)a[9] * b[3];
+    uint32_t t12 = c & 0x3FFFFFFUL; c = c >> 26;
+    c = c + (uint64_t)a[4] * b[9] +
+            (uint64_t)a[5] * b[8] +
+            (uint64_t)a[6] * b[7] +
+            (uint64_t)a[7] * b[6] +
+            (uint64_t)a[8] * b[5] +
+            (uint64_t)a[9] * b[4];
+    uint32_t t13 = c & 0x3FFFFFFUL; c = c >> 26;
+    c = c + (uint64_t)a[5] * b[9] +
+            (uint64_t)a[6] * b[8] +
+            (uint64_t)a[7] * b[7] +
+            (uint64_t)a[8] * b[6] +
+            (uint64_t)a[9] * b[5];
+    uint32_t t14 = c & 0x3FFFFFFUL; c = c >> 26;
+    c = c + (uint64_t)a[6] * b[9] +
+            (uint64_t)a[7] * b[8] +
+            (uint64_t)a[8] * b[7] +
+            (uint64_t)a[9] * b[6];
+    uint32_t t15 = c & 0x3FFFFFFUL; c = c >> 26;
+    c = c + (uint64_t)a[7] * b[9] +
+            (uint64_t)a[8] * b[8] +
+            (uint64_t)a[9] * b[7];
+    uint32_t t16 = c & 0x3FFFFFFUL; c = c >> 26;
+    c = c + (uint64_t)a[8] * b[9] +
+            (uint64_t)a[9] * b[8];
+    uint32_t t17 = c & 0x3FFFFFFUL; c = c >> 26;
+    c = c + (uint64_t)a[9] * b[9];
+    uint32_t t18 = c & 0x3FFFFFFUL; c = c >> 26;
+    uint32_t t19 = c;
+
+    c = t0 + (uint64_t)t10 * 0x3D10UL;
+    t0 = c & 0x3FFFFFFUL; c = c >> 26;
+    c = c + t1 + (uint64_t)t10*0x400UL + (uint64_t)t11 * 0x3D10UL;
+    t1 = c & 0x3FFFFFFUL; c = c >> 26;
+    c = c + t2 + (uint64_t)t11*0x400UL + (uint64_t)t12 * 0x3D10UL;
+    t2 = c & 0x3FFFFFFUL; c = c >> 26;
+    c = c + t3 + (uint64_t)t12*0x400UL + (uint64_t)t13 * 0x3D10UL;
+    r[3] = c & 0x3FFFFFFUL; c = c >> 26;
+    c = c + t4 + (uint64_t)t13*0x400UL + (uint64_t)t14 * 0x3D10UL;
+    r[4] = c & 0x3FFFFFFUL; c = c >> 26;
+    c = c + t5 + (uint64_t)t14*0x400UL + (uint64_t)t15 * 0x3D10UL;
+    r[5] = c & 0x3FFFFFFUL; c = c >> 26;
+    c = c + t6 + (uint64_t)t15*0x400UL + (uint64_t)t16 * 0x3D10UL;
+    r[6] = c & 0x3FFFFFFUL; c = c >> 26;
+    c = c + t7 + (uint64_t)t16*0x400UL + (uint64_t)t17 * 0x3D10UL;
+    r[7] = c & 0x3FFFFFFUL; c = c >> 26;
+    c = c + t8 + (uint64_t)t17*0x400UL + (uint64_t)t18 * 0x3D10UL;
+    r[8] = c & 0x3FFFFFFUL; c = c >> 26;
+    c = c + t9 + (uint64_t)t18*0x400UL + (uint64_t)t19 * 0x1000003D10ULL;
+    r[9] = c & 0x03FFFFFUL; c = c >> 22;
+    uint64_t d = t0 + c * 0x3D1UL;
+    r[0] = d & 0x3FFFFFFUL; d = d >> 26;
+    d = d + t1 + c*0x40;
+    r[1] = d & 0x3FFFFFFUL; d = d >> 26;
+    r[2] = t2 + d;
+}
+
+void static inline secp256k1_fe_sqr_inner(const uint32_t *a, uint32_t *r) {
+    uint64_t c = (uint64_t)a[0] * a[0];
+    uint32_t t0 = c & 0x3FFFFFFUL; c = c >> 26;
+    c = c + (uint64_t)(a[0]*2) * a[1];
+    uint32_t t1 = c & 0x3FFFFFFUL; c = c >> 26;
+    c = c + (uint64_t)(a[0]*2) * a[2] +
+            (uint64_t)a[1] * a[1];
+    uint32_t t2 = c & 0x3FFFFFFUL; c = c >> 26;
+    c = c + (uint64_t)(a[0]*2) * a[3] +
+            (uint64_t)(a[1]*2) * a[2];
+    uint32_t t3 = c & 0x3FFFFFFUL; c = c >> 26;
+    c = c + (uint64_t)(a[0]*2) * a[4] +
+            (uint64_t)(a[1]*2) * a[3] +
+            (uint64_t)a[2] * a[2];
+    uint32_t t4 = c & 0x3FFFFFFUL; c = c >> 26;
+    c = c + (uint64_t)(a[0]*2) * a[5] +
+            (uint64_t)(a[1]*2) * a[4] +
+            (uint64_t)(a[2]*2) * a[3];
+    uint32_t t5 = c & 0x3FFFFFFUL; c = c >> 26;
+    c = c + (uint64_t)(a[0]*2) * a[6] +
+            (uint64_t)(a[1]*2) * a[5] +
+            (uint64_t)(a[2]*2) * a[4] +
+            (uint64_t)a[3] * a[3];
+    uint32_t t6 = c & 0x3FFFFFFUL; c = c >> 26;
+    c = c + (uint64_t)(a[0]*2) * a[7] +
+            (uint64_t)(a[1]*2) * a[6] +
+            (uint64_t)(a[2]*2) * a[5] +
+            (uint64_t)(a[3]*2) * a[4];
+    uint32_t t7 = c & 0x3FFFFFFUL; c = c >> 26;
+    c = c + (uint64_t)(a[0]*2) * a[8] +
+            (uint64_t)(a[1]*2) * a[7] +
+            (uint64_t)(a[2]*2) * a[6] +
+            (uint64_t)(a[3]*2) * a[5] +
+            (uint64_t)a[4] * a[4];
+    uint32_t t8 = c & 0x3FFFFFFUL; c = c >> 26;
+    c = c + (uint64_t)(a[0]*2) * a[9] +
+            (uint64_t)(a[1]*2) * a[8] +
+            (uint64_t)(a[2]*2) * a[7] +
+            (uint64_t)(a[3]*2) * a[6] +
+            (uint64_t)(a[4]*2) * a[5];
+    uint32_t t9 = c & 0x3FFFFFFUL; c = c >> 26;
+    c = c + (uint64_t)(a[1]*2) * a[9] +
+            (uint64_t)(a[2]*2) * a[8] +
+            (uint64_t)(a[3]*2) * a[7] +
+            (uint64_t)(a[4]*2) * a[6] +
+            (uint64_t)a[5] * a[5];
+    uint32_t t10 = c & 0x3FFFFFFUL; c = c >> 26;
+    c = c + (uint64_t)(a[2]*2) * a[9] +
+            (uint64_t)(a[3]*2) * a[8] +
+            (uint64_t)(a[4]*2) * a[7] +
+            (uint64_t)(a[5]*2) * a[6];
+    uint32_t t11 = c & 0x3FFFFFFUL; c = c >> 26;
+    c = c + (uint64_t)(a[3]*2) * a[9] +
+            (uint64_t)(a[4]*2) * a[8] +
+            (uint64_t)(a[5]*2) * a[7] +
+            (uint64_t)a[6] * a[6];
+    uint32_t t12 = c & 0x3FFFFFFUL; c = c >> 26;
+    c = c + (uint64_t)(a[4]*2) * a[9] +
+            (uint64_t)(a[5]*2) * a[8] +
+            (uint64_t)(a[6]*2) * a[7];
+    uint32_t t13 = c & 0x3FFFFFFUL; c = c >> 26;
+    c = c + (uint64_t)(a[5]*2) * a[9] +
+            (uint64_t)(a[6]*2) * a[8] +
+            (uint64_t)a[7] * a[7];
+    uint32_t t14 = c & 0x3FFFFFFUL; c = c >> 26;
+    c = c + (uint64_t)(a[6]*2) * a[9] +
+            (uint64_t)(a[7]*2) * a[8];
+    uint32_t t15 = c & 0x3FFFFFFUL; c = c >> 26;
+    c = c + (uint64_t)(a[7]*2) * a[9] +
+            (uint64_t)a[8] * a[8];
+    uint32_t t16 = c & 0x3FFFFFFUL; c = c >> 26;
+    c = c + (uint64_t)(a[8]*2) * a[9];
+    uint32_t t17 = c & 0x3FFFFFFUL; c = c >> 26;
+    c = c + (uint64_t)a[9] * a[9];
+    uint32_t t18 = c & 0x3FFFFFFUL; c = c >> 26;
+    uint32_t t19 = c;
+
+    c = t0 + (uint64_t)t10 * 0x3D10UL;
+    t0 = c & 0x3FFFFFFUL; c = c >> 26;
+    c = c + t1 + (uint64_t)t10*0x400UL + (uint64_t)t11 * 0x3D10UL;
+    t1 = c & 0x3FFFFFFUL; c = c >> 26;
+    c = c + t2 + (uint64_t)t11*0x400UL + (uint64_t)t12 * 0x3D10UL;
+    t2 = c & 0x3FFFFFFUL; c = c >> 26;
+    c = c + t3 + (uint64_t)t12*0x400UL + (uint64_t)t13 * 0x3D10UL;
+    r[3] = c & 0x3FFFFFFUL; c = c >> 26;
+    c = c + t4 + (uint64_t)t13*0x400UL + (uint64_t)t14 * 0x3D10UL;
+    r[4] = c & 0x3FFFFFFUL; c = c >> 26;
+    c = c + t5 + (uint64_t)t14*0x400UL + (uint64_t)t15 * 0x3D10UL;
+    r[5] = c & 0x3FFFFFFUL; c = c >> 26;
+    c = c + t6 + (uint64_t)t15*0x400UL + (uint64_t)t16 * 0x3D10UL;
+    r[6] = c & 0x3FFFFFFUL; c = c >> 26;
+    c = c + t7 + (uint64_t)t16*0x400UL + (uint64_t)t17 * 0x3D10UL;
+    r[7] = c & 0x3FFFFFFUL; c = c >> 26;
+    c = c + t8 + (uint64_t)t17*0x400UL + (uint64_t)t18 * 0x3D10UL;
+    r[8] = c & 0x3FFFFFFUL; c = c >> 26;
+    c = c + t9 + (uint64_t)t18*0x400UL + (uint64_t)t19 * 0x1000003D10ULL;
+    r[9] = c & 0x03FFFFFUL; c = c >> 22;
+    uint64_t d = t0 + c * 0x3D1UL;
+    r[0] = d & 0x3FFFFFFUL; d = d >> 26;
+    d = d + t1 + c*0x40;
+    r[1] = d & 0x3FFFFFFUL; d = d >> 26;
+    r[2] = t2 + d;
+}
+
+
+void static secp256k1_fe_mul(secp256k1_fe_t *r, const secp256k1_fe_t *a, const secp256k1_fe_t *b) {
+#ifdef VERIFY
+    assert(a->magnitude <= 8);
+    assert(b->magnitude <= 8);
+    r->magnitude = 1;
+    r->normalized = 0;
+#endif
+    secp256k1_fe_mul_inner(a->n, b->n, r->n);
+}
+
+void static secp256k1_fe_sqr(secp256k1_fe_t *r, const secp256k1_fe_t *a) {
+#ifdef VERIFY
+    assert(a->magnitude <= 8);
+    r->magnitude = 1;
+    r->normalized = 0;
+#endif
+    secp256k1_fe_sqr_inner(a->n, r->n);
+}
+
+#endif
diff --git a/secp256k1/impl/field_5x52.h b/secp256k1/impl/field_5x52.h
new file mode 100644
index 000000000..5347189f1
--- /dev/null
+++ b/secp256k1/impl/field_5x52.h
@@ -0,0 +1,196 @@
+// Copyright (c) 2013 Pieter Wuille
+// Distributed under the MIT/X11 software license, see the accompanying
+// file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
+#ifndef _SECP256K1_FIELD_REPR_IMPL_H_
+#define _SECP256K1_FIELD_REPR_IMPL_H_
+
+#include <assert.h>
+#include <string.h>
+#include "../num.h"
+#include "../field.h"
+
+#if defined(USE_FIELD_5X52_ASM)
+#include "field_5x52_asm.h"
+#elif defined(USE_FIELD_5X52_INT128)
+#include "field_5x52_int128.h"
+#else
+#error "Please select field_5x52 implementation"
+#endif
+
+/** Implements arithmetic modulo FFFFFFFF FFFFFFFF FFFFFFFF FFFFFFFF FFFFFFFF FFFFFFFF FFFFFFFE FFFFFC2F,
+ *  represented as 5 uint64_t's in base 2^52. The values are allowed to contain >52 each. In particular,
+ *  each FieldElem has a 'magnitude' associated with it. Internally, a magnitude M means each element
+ *  is at most M*(2^53-1), except the most significant one, which is limited to M*(2^49-1). All operations
+ *  accept any input with magnitude at most M, and have different rules for propagating magnitude to their
+ *  output.
+ */
+
+void static secp256k1_fe_inner_start(void) {}
+void static secp256k1_fe_inner_stop(void) {}
+
+void static secp256k1_fe_normalize(secp256k1_fe_t *r) {
+    uint64_t c;
+    c = r->n[0];
+    uint64_t t0 = c & 0xFFFFFFFFFFFFFULL;
+    c = (c >> 52) + r->n[1];
+    uint64_t t1 = c & 0xFFFFFFFFFFFFFULL;
+    c = (c >> 52) + r->n[2];
+    uint64_t t2 = c & 0xFFFFFFFFFFFFFULL;
+    c = (c >> 52) + r->n[3];
+    uint64_t t3 = c & 0xFFFFFFFFFFFFFULL;
+    c = (c >> 52) + r->n[4];
+    uint64_t t4 = c & 0x0FFFFFFFFFFFFULL;
+    c >>= 48;
+
+    // The following code will not modify the t's if c is initially 0.
+    c = c * 0x1000003D1ULL + t0;
+    t0 = c & 0xFFFFFFFFFFFFFULL;
+    c = (c >> 52) + t1;
+    t1 = c & 0xFFFFFFFFFFFFFULL;
+    c = (c >> 52) + t2;
+    t2 = c & 0xFFFFFFFFFFFFFULL;
+    c = (c >> 52) + t3;
+    t3 = c & 0xFFFFFFFFFFFFFULL;
+    c = (c >> 52) + t4;
+    t4 = c & 0x0FFFFFFFFFFFFULL;
+    assert((c >> 48) == 0);
+
+    // Subtract p if result >= p
+    uint64_t mask = -(int64_t)((t4 < 0xFFFFFFFFFFFFULL) | (t3 < 0xFFFFFFFFFFFFFULL) | (t2 < 0xFFFFFFFFFFFFFULL) | (t1 < 0xFFFFFFFFFFFFFULL) | (t0 < 0xFFFFEFFFFFC2FULL));
+    t4 &= mask;
+    t3 &= mask;
+    t2 &= mask;
+    t1 &= mask;
+    t0 -= (~mask & 0xFFFFEFFFFFC2FULL);
+
+    // push internal variables back
+    r->n[0] = t0; r->n[1] = t1; r->n[2] = t2; r->n[3] = t3; r->n[4] = t4;
+
+#ifdef VERIFY
+    r->magnitude = 1;
+    r->normalized = 1;
+#endif
+}
+
+void static inline secp256k1_fe_set_int(secp256k1_fe_t *r, int a) {
+    r->n[0] = a;
+    r->n[1] = r->n[2] = r->n[3] = r->n[4] = 0;
+#ifdef VERIFY
+    r->magnitude = 1;
+    r->normalized = 1;
+#endif
+}
+
+// TODO: not constant time!
+int static inline secp256k1_fe_is_zero(const secp256k1_fe_t *a) {
+#ifdef VERIFY
+    assert(a->normalized);
+#endif
+    return (a->n[0] == 0 && a->n[1] == 0 && a->n[2] == 0 && a->n[3] == 0 && a->n[4] == 0);
+}
+
+int static inline secp256k1_fe_is_odd(const secp256k1_fe_t *a) {
+#ifdef VERIFY
+    assert(a->normalized);
+#endif
+    return a->n[0] & 1;
+}
+
+// TODO: not constant time!
+int static inline secp256k1_fe_equal(const secp256k1_fe_t *a, const secp256k1_fe_t *b) {
+#ifdef VERIFY
+    assert(a->normalized);
+    assert(b->normalized);
+#endif
+    return (a->n[0] == b->n[0] && a->n[1] == b->n[1] && a->n[2] == b->n[2] && a->n[3] == b->n[3] && a->n[4] == b->n[4]);
+}
+
+void static secp256k1_fe_set_b32(secp256k1_fe_t *r, const unsigned char *a) {
+    r->n[0] = r->n[1] = r->n[2] = r->n[3] = r->n[4] = 0;
+    for (int i=0; i<32; i++) {
+        for (int j=0; j<2; j++) {
+            int limb = (8*i+4*j)/52;
+            int shift = (8*i+4*j)%52;
+            r->n[limb] |= (uint64_t)((a[31-i] >> (4*j)) & 0xF) << shift;
+        }
+    }
+#ifdef VERIFY
+    r->magnitude = 1;
+    r->normalized = 1;
+#endif
+}
+
+/** Convert a field element to a 32-byte big endian value. Requires the input to be normalized */
+void static secp256k1_fe_get_b32(unsigned char *r, const secp256k1_fe_t *a) {
+#ifdef VERIFY
+    assert(a->normalized);
+#endif
+    for (int i=0; i<32; i++) {
+        int c = 0;
+        for (int j=0; j<2; j++) {
+            int limb = (8*i+4*j)/52;
+            int shift = (8*i+4*j)%52;
+            c |= ((a->n[limb] >> shift) & 0xF) << (4 * j);
+        }
+        r[31-i] = c;
+    }
+}
+
+void static inline secp256k1_fe_negate(secp256k1_fe_t *r, const secp256k1_fe_t *a, int m) {
+#ifdef VERIFY
+    assert(a->magnitude <= m);
+    r->magnitude = m + 1;
+    r->normalized = 0;
+#endif
+    r->n[0] = 0xFFFFEFFFFFC2FULL * (m + 1) - a->n[0];
+    r->n[1] = 0xFFFFFFFFFFFFFULL * (m + 1) - a->n[1];
+    r->n[2] = 0xFFFFFFFFFFFFFULL * (m + 1) - a->n[2];
+    r->n[3] = 0xFFFFFFFFFFFFFULL * (m + 1) - a->n[3];
+    r->n[4] = 0x0FFFFFFFFFFFFULL * (m + 1) - a->n[4];
+}
+
+void static inline secp256k1_fe_mul_int(secp256k1_fe_t *r, int a) {
+#ifdef VERIFY
+    r->magnitude *= a;
+    r->normalized = 0;
+#endif
+    r->n[0] *= a;
+    r->n[1] *= a;
+    r->n[2] *= a;
+    r->n[3] *= a;
+    r->n[4] *= a;
+}
+
+void static inline secp256k1_fe_add(secp256k1_fe_t *r, const secp256k1_fe_t *a) {
+#ifdef VERIFY
+    r->magnitude += a->magnitude;
+    r->normalized = 0;
+#endif
+    r->n[0] += a->n[0];
+    r->n[1] += a->n[1];
+    r->n[2] += a->n[2];
+    r->n[3] += a->n[3];
+    r->n[4] += a->n[4];
+}
+
+void static secp256k1_fe_mul(secp256k1_fe_t *r, const secp256k1_fe_t *a, const secp256k1_fe_t *b) {
+#ifdef VERIFY
+    assert(a->magnitude <= 8);
+    assert(b->magnitude <= 8);
+    r->magnitude = 1;
+    r->normalized = 0;
+#endif
+    secp256k1_fe_mul_inner(a->n, b->n, r->n);
+}
+
+void static secp256k1_fe_sqr(secp256k1_fe_t *r, const secp256k1_fe_t *a) {
+#ifdef VERIFY
+    assert(a->magnitude <= 8);
+    r->magnitude = 1;
+    r->normalized = 0;
+#endif
+    secp256k1_fe_sqr_inner(a->n, r->n);
+}
+
+#endif
diff --git a/secp256k1/impl/field_5x52_asm.h b/secp256k1/impl/field_5x52_asm.h
new file mode 100644
index 000000000..93c6ab6b5
--- /dev/null
+++ b/secp256k1/impl/field_5x52_asm.h
@@ -0,0 +1,11 @@
+// Copyright (c) 2013 Pieter Wuille
+// Distributed under the MIT/X11 software license, see the accompanying
+// file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
+#ifndef _SECP256K1_FIELD_INNER5X52_IMPL_H_
+#define _SECP256K1_FIELD_INNER5X52_IMPL_H_
+
+void __attribute__ ((sysv_abi)) secp256k1_fe_mul_inner(const uint64_t *a, const uint64_t *b, uint64_t *r);
+void __attribute__ ((sysv_abi)) secp256k1_fe_sqr_inner(const uint64_t *a, uint64_t *r);
+
+#endif
diff --git a/secp256k1/impl/field_5x52_int128.h b/secp256k1/impl/field_5x52_int128.h
new file mode 100644
index 000000000..23cb13462
--- /dev/null
+++ b/secp256k1/impl/field_5x52_int128.h
@@ -0,0 +1,105 @@
+// Copyright (c) 2013 Pieter Wuille
+// Distributed under the MIT/X11 software license, see the accompanying
+// file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
+#ifndef _SECP256K1_FIELD_INNER5X52_IMPL_H_
+#define _SECP256K1_FIELD_INNER5X52_IMPL_H_
+
+#include <stdint.h>
+
+void static inline secp256k1_fe_mul_inner(const uint64_t *a, const uint64_t *b, uint64_t *r) {
+    __int128 c = (__int128)a[0] * b[0];
+    uint64_t t0 = c & 0xFFFFFFFFFFFFFULL; c = c >> 52; // c max 0FFFFFFFFFFFFFE0
+    c = c + (__int128)a[0] * b[1] +
+            (__int128)a[1] * b[0];
+    uint64_t t1 = c & 0xFFFFFFFFFFFFFULL; c = c >> 52; // c max 20000000000000BF
+    c = c + (__int128)a[0] * b[2] +
+            (__int128)a[1] * b[1] +
+            (__int128)a[2] * b[0];
+    uint64_t t2 = c & 0xFFFFFFFFFFFFFULL; c = c >> 52; // c max 30000000000001A0
+    c = c + (__int128)a[0] * b[3] +
+            (__int128)a[1] * b[2] +
+            (__int128)a[2] * b[1] +
+            (__int128)a[3] * b[0];
+    uint64_t t3 = c & 0xFFFFFFFFFFFFFULL; c = c >> 52; // c max 4000000000000280
+    c = c + (__int128)a[0] * b[4] +
+            (__int128)a[1] * b[3] +
+            (__int128)a[2] * b[2] +
+            (__int128)a[3] * b[1] +
+            (__int128)a[4] * b[0];
+    uint64_t t4 = c & 0xFFFFFFFFFFFFFULL; c = c >> 52; // c max 320000000000037E
+    c = c + (__int128)a[1] * b[4] +
+            (__int128)a[2] * b[3] +
+            (__int128)a[3] * b[2] +
+            (__int128)a[4] * b[1];
+    uint64_t t5 = c & 0xFFFFFFFFFFFFFULL; c = c >> 52; // c max 22000000000002BE
+    c = c + (__int128)a[2] * b[4] +
+            (__int128)a[3] * b[3] +
+            (__int128)a[4] * b[2];
+    uint64_t t6 = c & 0xFFFFFFFFFFFFFULL; c = c >> 52; // c max 12000000000001DE
+    c = c + (__int128)a[3] * b[4] +
+            (__int128)a[4] * b[3];
+    uint64_t t7 = c & 0xFFFFFFFFFFFFFULL; c = c >> 52; // c max 02000000000000FE
+    c = c + (__int128)a[4] * b[4];
+    uint64_t t8 = c & 0xFFFFFFFFFFFFFULL; c = c >> 52; // c max 001000000000001E
+    uint64_t t9 = c;
+
+    c = t0 + (__int128)t5 * 0x1000003D10ULL;
+    t0 = c & 0xFFFFFFFFFFFFFULL; c = c >> 52; // c max 0000001000003D10
+    c = c + t1 + (__int128)t6 * 0x1000003D10ULL;
+    t1 = c & 0xFFFFFFFFFFFFFULL; c = c >> 52; // c max 0000001000003D10
+    c = c + t2 + (__int128)t7 * 0x1000003D10ULL;
+    r[2] = c & 0xFFFFFFFFFFFFFULL; c = c >> 52; // c max 0000001000003D10
+    c = c + t3 + (__int128)t8 * 0x1000003D10ULL;
+    r[3] = c & 0xFFFFFFFFFFFFFULL; c = c >> 52; // c max 0000001000003D10
+    c = c + t4 + (__int128)t9 * 0x1000003D10ULL;
+    r[4] = c & 0x0FFFFFFFFFFFFULL; c = c >> 48; // c max 000001000003D110
+    c = t0 + (__int128)c * 0x1000003D1ULL;
+    r[0] = c & 0xFFFFFFFFFFFFFULL; c = c >> 52; // c max 1000008
+    r[1] = t1 + c;
+
+}
+
+void static inline secp256k1_fe_sqr_inner(const uint64_t *a, uint64_t *r) {
+    __int128 c = (__int128)a[0] * a[0];
+    uint64_t t0 = c & 0xFFFFFFFFFFFFFULL; c = c >> 52; // c max 0FFFFFFFFFFFFFE0
+    c = c + (__int128)(a[0]*2) * a[1];
+    uint64_t t1 = c & 0xFFFFFFFFFFFFFULL; c = c >> 52; // c max 20000000000000BF
+    c = c + (__int128)(a[0]*2) * a[2] +
+            (__int128)a[1] * a[1];
+    uint64_t t2 = c & 0xFFFFFFFFFFFFFULL; c = c >> 52; // c max 30000000000001A0
+    c = c + (__int128)(a[0]*2) * a[3] +
+            (__int128)(a[1]*2) * a[2];
+    uint64_t t3 = c & 0xFFFFFFFFFFFFFULL; c = c >> 52; // c max 4000000000000280
+    c = c + (__int128)(a[0]*2) * a[4] +
+            (__int128)(a[1]*2) * a[3] +
+            (__int128)a[2] * a[2];
+    uint64_t t4 = c & 0xFFFFFFFFFFFFFULL; c = c >> 52; // c max 320000000000037E
+    c = c + (__int128)(a[1]*2) * a[4] +
+            (__int128)(a[2]*2) * a[3];
+    uint64_t t5 = c & 0xFFFFFFFFFFFFFULL; c = c >> 52; // c max 22000000000002BE
+    c = c + (__int128)(a[2]*2) * a[4] +
+            (__int128)a[3] * a[3];
+    uint64_t t6 = c & 0xFFFFFFFFFFFFFULL; c = c >> 52; // c max 12000000000001DE
+    c = c + (__int128)(a[3]*2) * a[4];
+    uint64_t t7 = c & 0xFFFFFFFFFFFFFULL; c = c >> 52; // c max 02000000000000FE
+    c = c + (__int128)a[4] * a[4];
+    uint64_t t8 = c & 0xFFFFFFFFFFFFFULL; c = c >> 52; // c max 001000000000001E
+    uint64_t t9 = c;
+    c = t0 + (__int128)t5 * 0x1000003D10ULL;
+    t0 = c & 0xFFFFFFFFFFFFFULL; c = c >> 52; // c max 0000001000003D10
+    c = c + t1 + (__int128)t6 * 0x1000003D10ULL;
+    t1 = c & 0xFFFFFFFFFFFFFULL; c = c >> 52; // c max 0000001000003D10
+    c = c + t2 + (__int128)t7 * 0x1000003D10ULL;
+    r[2] = c & 0xFFFFFFFFFFFFFULL; c = c >> 52; // c max 0000001000003D10
+    c = c + t3 + (__int128)t8 * 0x1000003D10ULL;
+    r[3] = c & 0xFFFFFFFFFFFFFULL; c = c >> 52; // c max 0000001000003D10
+    c = c + t4 + (__int128)t9 * 0x1000003D10ULL;
+    r[4] = c & 0x0FFFFFFFFFFFFULL; c = c >> 48; // c max 000001000003D110
+    c = t0 + (__int128)c * 0x1000003D1ULL;
+    r[0] = c & 0xFFFFFFFFFFFFFULL; c = c >> 52; // c max 1000008
+    r[1] = t1 + c;
+
+}
+
+#endif
diff --git a/secp256k1/impl/field_gmp.h b/secp256k1/impl/field_gmp.h
new file mode 100644
index 000000000..6172ef48e
--- /dev/null
+++ b/secp256k1/impl/field_gmp.h
@@ -0,0 +1,155 @@
+// Copyright (c) 2013 Pieter Wuille
+// Distributed under the MIT/X11 software license, see the accompanying
+// file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
+#ifndef _SECP256K1_FIELD_REPR_IMPL_H_
+#define _SECP256K1_FIELD_REPR_IMPL_H_
+
+#include <stdio.h>
+#include <assert.h>
+#include <string.h>
+#include "../num.h"
+#include "../field.h"
+
+static mp_limb_t secp256k1_field_p[FIELD_LIMBS];
+static mp_limb_t secp256k1_field_pc[(33+GMP_NUMB_BITS-1)/GMP_NUMB_BITS];
+
+void static secp256k1_fe_inner_start(void) {
+    for (int i=0; i<(33+GMP_NUMB_BITS-1)/GMP_NUMB_BITS; i++)
+        secp256k1_field_pc[i] = 0;
+    secp256k1_field_pc[0] += 0x3D1UL;
+    secp256k1_field_pc[32/GMP_NUMB_BITS] += (1UL << (32 % GMP_NUMB_BITS));
+    for (int i=0; i<FIELD_LIMBS; i++) {
+        secp256k1_field_p[i] = 0;
+    }
+    mpn_sub(secp256k1_field_p, secp256k1_field_p, FIELD_LIMBS, secp256k1_field_pc, (33+GMP_NUMB_BITS-1)/GMP_NUMB_BITS);
+}
+
+void static secp256k1_fe_inner_stop(void) {
+}
+
+void static secp256k1_fe_normalize(secp256k1_fe_t *r) {
+    if (r->n[FIELD_LIMBS] != 0) {
+#if (GMP_NUMB_BITS >= 40)
+        mp_limb_t carry = mpn_add_1(r->n, r->n, FIELD_LIMBS, 0x1000003D1ULL * r->n[FIELD_LIMBS]);
+        mpn_add_1(r->n, r->n, FIELD_LIMBS, 0x1000003D1ULL * carry);
+#else
+        mp_limb_t carry = mpn_add_1(r->n, r->n, FIELD_LIMBS, 0x3D1UL * r->n[FIELD_LIMBS]) + 
+                          mpn_add_1(r->n+(32/GMP_NUMB_BITS), r->n+(32/GMP_NUMB_BITS), FIELD_LIMBS-(32/GMP_NUMB_BITS), r->n[FIELD_LIMBS] << (32 % GMP_NUMB_BITS));
+        mpn_add_1(r->n, r->n, FIELD_LIMBS, 0x3D1UL * carry);
+        mpn_add_1(r->n+(32/GMP_NUMB_BITS), r->n+(32/GMP_NUMB_BITS), FIELD_LIMBS-(32/GMP_NUMB_BITS), carry << (32%GMP_NUMB_BITS));
+#endif
+        r->n[FIELD_LIMBS] = 0;
+    }
+    if (mpn_cmp(r->n, secp256k1_field_p, FIELD_LIMBS) >= 0)
+        mpn_sub(r->n, r->n, FIELD_LIMBS, secp256k1_field_p, FIELD_LIMBS);
+}
+
+void static inline secp256k1_fe_set_int(secp256k1_fe_t *r, int a) {
+    r->n[0] = a;
+    for (int i=1; i<FIELD_LIMBS+1; i++)
+        r->n[i] = 0;
+}
+
+int static inline secp256k1_fe_is_zero(const secp256k1_fe_t *a) {
+    int ret = 1;
+    for (int i=0; i<FIELD_LIMBS+1; i++)
+        ret &= (a->n[i] == 0);
+    return ret;
+}
+
+int static inline secp256k1_fe_is_odd(const secp256k1_fe_t *a) {
+    return a->n[0] & 1;
+}
+
+int static inline secp256k1_fe_equal(const secp256k1_fe_t *a, const secp256k1_fe_t *b) {
+    int ret = 1;
+    for (int i=0; i<FIELD_LIMBS+1; i++)
+        ret &= (a->n[i] == b->n[i]);
+    return ret;
+}
+
+void static secp256k1_fe_set_b32(secp256k1_fe_t *r, const unsigned char *a) {
+    for (int i=0; i<FIELD_LIMBS+1; i++)
+        r->n[i] = 0;
+    for (int i=0; i<256; i++) {
+        int limb = i/GMP_NUMB_BITS;
+        int shift = i%GMP_NUMB_BITS;
+        r->n[limb] |= (mp_limb_t)((a[31-i/8] >> (i%8)) & 0x1) << shift;
+    }
+}
+
+/** Convert a field element to a 32-byte big endian value. Requires the input to be normalized */
+void static secp256k1_fe_get_b32(unsigned char *r, const secp256k1_fe_t *a) {
+    for (int i=0; i<32; i++) {
+        int c = 0;
+        for (int j=0; j<8; j++) {
+            int limb = (8*i+j)/GMP_NUMB_BITS;
+            int shift = (8*i+j)%GMP_NUMB_BITS;
+            c |= ((a->n[limb] >> shift) & 0x1) << j;
+        }
+        r[31-i] = c;
+    }
+}
+
+void static inline secp256k1_fe_negate(secp256k1_fe_t *r, const secp256k1_fe_t *a, int m) {
+    *r = *a;
+    secp256k1_fe_normalize(r);
+    for (int i=0; i<FIELD_LIMBS; i++)
+        r->n[i] = ~(r->n[i]);
+#if (GMP_NUMB_BITS >= 33)
+    mpn_sub_1(r->n, r->n, FIELD_LIMBS, 0x1000003D0ULL);
+#else
+    mpn_sub_1(r->n, r->n, FIELD_LIMBS, 0x3D0UL);
+    mpn_sub_1(r->n+(32/GMP_NUMB_BITS), r->n+(32/GMP_NUMB_BITS), FIELD_LIMBS-(32/GMP_NUMB_BITS), 0x1UL << (32%GMP_NUMB_BITS));
+#endif
+}
+
+void static inline secp256k1_fe_mul_int(secp256k1_fe_t *r, int a) {
+    mpn_mul_1(r->n, r->n, FIELD_LIMBS+1, a);
+}
+
+void static inline secp256k1_fe_add(secp256k1_fe_t *r, const secp256k1_fe_t *a) {
+    mpn_add(r->n, r->n, FIELD_LIMBS+1, a->n, FIELD_LIMBS+1);
+}
+
+void static secp256k1_fe_reduce(secp256k1_fe_t *r, mp_limb_t *tmp) {
+    // <A1 A2 A3 A4> <B1 B2 B3 B4>
+    //       B1 B2 B3 B4
+    // + C * A1 A2 A3 A4
+    // +  A1 A2 A3 A4
+
+#if (GMP_NUMB_BITS >= 33)
+    mp_limb_t o = mpn_addmul_1(tmp, tmp+FIELD_LIMBS, FIELD_LIMBS, 0x1000003D1ULL);
+#else
+    mp_limb_t o = mpn_addmul_1(tmp, tmp+FIELD_LIMBS, FIELD_LIMBS, 0x3D1UL) +
+                  mpn_addmul_1(tmp+(32/GMP_NUMB_BITS), tmp+FIELD_LIMBS, FIELD_LIMBS-(32/GMP_NUMB_BITS), 0x1UL << (32%GMP_NUMB_BITS));
+#endif
+    mp_limb_t q[1+(33+GMP_NUMB_BITS-1)/GMP_NUMB_BITS];
+    q[(33+GMP_NUMB_BITS-1)/GMP_NUMB_BITS] = mpn_mul_1(q, secp256k1_field_pc, (33+GMP_NUMB_BITS-1)/GMP_NUMB_BITS, o);
+#if (GMP_NUMB_BITS <= 32)
+    mp_limb_t o2 = tmp[2*FIELD_LIMBS-(32/GMP_NUMB_BITS)] << (32%GMP_NUMB_BITS);
+    q[(33+GMP_NUMB_BITS-1)/GMP_NUMB_BITS] += mpn_addmul_1(q, secp256k1_field_pc, (33+GMP_NUMB_BITS-1)/GMP_NUMB_BITS, o2);
+#endif
+    r->n[FIELD_LIMBS] = mpn_add(r->n, tmp, FIELD_LIMBS, q, 1+(33+GMP_NUMB_BITS-1)/GMP_NUMB_BITS);
+}
+
+void static secp256k1_fe_mul(secp256k1_fe_t *r, const secp256k1_fe_t *a, const secp256k1_fe_t *b) {
+    secp256k1_fe_t ac = *a;
+    secp256k1_fe_t bc = *b;
+    secp256k1_fe_normalize(&ac);
+    secp256k1_fe_normalize(&bc);
+    mp_limb_t tmp[2*FIELD_LIMBS];
+    mpn_mul_n(tmp, ac.n, bc.n, FIELD_LIMBS);
+    secp256k1_fe_reduce(r, tmp);
+}
+
+void static secp256k1_fe_sqr(secp256k1_fe_t *r, const secp256k1_fe_t *a) {
+    secp256k1_fe_t ac = *a;
+    secp256k1_fe_normalize(&ac);
+    mp_limb_t tmp[2*FIELD_LIMBS];
+    mpn_sqr(tmp, ac.n, FIELD_LIMBS);
+    secp256k1_fe_reduce(r, tmp);
+}
+
+#endif
diff --git a/secp256k1/impl/group.h b/secp256k1/impl/group.h
new file mode 100644
index 000000000..cfbe80081
--- /dev/null
+++ b/secp256k1/impl/group.h
@@ -0,0 +1,403 @@
+// Copyright (c) 2013 Pieter Wuille
+// Distributed under the MIT/X11 software license, see the accompanying
+// file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
+#ifndef _SECP256K1_GROUP_IMPL_H_
+#define _SECP256K1_GROUP_IMPL_H_
+
+#include <string.h>
+
+#include "../num.h"
+#include "../field.h"
+#include "../group.h"
+
+void static secp256k1_ge_set_infinity(secp256k1_ge_t *r) {
+    r->infinity = 1;
+}
+
+void static secp256k1_ge_set_xy(secp256k1_ge_t *r, const secp256k1_fe_t *x, const secp256k1_fe_t *y) {
+    r->infinity = 0;
+    r->x = *x;
+    r->y = *y;
+}
+
+int static secp256k1_ge_is_infinity(const secp256k1_ge_t *a) {
+    return a->infinity;
+}
+
+void static secp256k1_ge_neg(secp256k1_ge_t *r, const secp256k1_ge_t *a) {
+    r->infinity = a->infinity;
+    r->x = a->x;
+    r->y = a->y;
+    secp256k1_fe_normalize(&r->y);
+    secp256k1_fe_negate(&r->y, &r->y, 1);
+}
+
+void static secp256k1_ge_get_hex(char *r, int *rlen, const secp256k1_ge_t *a) {
+    char cx[65]; int lx=65;
+    char cy[65]; int ly=65;
+    secp256k1_fe_get_hex(cx, &lx, &a->x);
+    secp256k1_fe_get_hex(cy, &ly, &a->y);
+    lx = strlen(cx);
+    ly = strlen(cy);
+    int len = lx + ly + 3 + 1;
+    if (*rlen < len) {
+        *rlen = len;
+        return;
+    }
+    *rlen = len;
+    r[0] = '(';
+    memcpy(r+1, cx, lx);
+    r[1+lx] = ',';
+    memcpy(r+2+lx, cy, ly);
+    r[2+lx+ly] = ')';
+    r[3+lx+ly] = 0;
+}
+
+void static secp256k1_ge_set_gej(secp256k1_ge_t *r, secp256k1_gej_t *a) {
+    secp256k1_fe_inv_var(&a->z, &a->z);
+    secp256k1_fe_t z2; secp256k1_fe_sqr(&z2, &a->z);
+    secp256k1_fe_t z3; secp256k1_fe_mul(&z3, &a->z, &z2);
+    secp256k1_fe_mul(&a->x, &a->x, &z2);
+    secp256k1_fe_mul(&a->y, &a->y, &z3);
+    secp256k1_fe_set_int(&a->z, 1);
+    r->infinity = a->infinity;
+    r->x = a->x;
+    r->y = a->y;
+}
+
+void static secp256k1_gej_set_infinity(secp256k1_gej_t *r) {
+    r->infinity = 1;
+}
+
+void static secp256k1_gej_set_xy(secp256k1_gej_t *r, const secp256k1_fe_t *x, const secp256k1_fe_t *y) {
+    r->infinity = 0;
+    r->x = *x;
+    r->y = *y;
+    secp256k1_fe_set_int(&r->z, 1);
+}
+
+void static secp256k1_ge_set_xo(secp256k1_ge_t *r, const secp256k1_fe_t *x, int odd) {
+    r->x = *x;
+    secp256k1_fe_t x2; secp256k1_fe_sqr(&x2, x);
+    secp256k1_fe_t x3; secp256k1_fe_mul(&x3, x, &x2);
+    r->infinity = 0;
+    secp256k1_fe_t c; secp256k1_fe_set_int(&c, 7);
+    secp256k1_fe_add(&c, &x3);
+    secp256k1_fe_sqrt(&r->y, &c);
+    secp256k1_fe_normalize(&r->y);
+    if (secp256k1_fe_is_odd(&r->y) != odd)
+        secp256k1_fe_negate(&r->y, &r->y, 1);
+}
+
+void static secp256k1_gej_set_ge(secp256k1_gej_t *r, const secp256k1_ge_t *a) {
+   r->infinity = a->infinity;
+   r->x = a->x;
+   r->y = a->y;
+   secp256k1_fe_set_int(&r->z, 1);
+}
+
+void static secp256k1_gej_get_x(secp256k1_fe_t *r, const secp256k1_gej_t *a) {
+    secp256k1_fe_t zi2; secp256k1_fe_inv_var(&zi2, &a->z); secp256k1_fe_sqr(&zi2, &zi2);
+    secp256k1_fe_mul(r, &a->x, &zi2);
+}
+
+void static secp256k1_gej_neg(secp256k1_gej_t *r, const secp256k1_gej_t *a) {
+    r->infinity = a->infinity;
+    r->x = a->x;
+    r->y = a->y;
+    r->z = a->z;
+    secp256k1_fe_normalize(&r->y);
+    secp256k1_fe_negate(&r->y, &r->y, 1);
+}
+
+int static secp256k1_gej_is_infinity(const secp256k1_gej_t *a) {
+    return a->infinity;
+}
+
+int static secp256k1_gej_is_valid(const secp256k1_gej_t *a) {
+    if (a->infinity)
+        return 0;
+    // y^2 = x^3 + 7
+    // (Y/Z^3)^2 = (X/Z^2)^3 + 7
+    // Y^2 / Z^6 = X^3 / Z^6 + 7
+    // Y^2 = X^3 + 7*Z^6
+    secp256k1_fe_t y2; secp256k1_fe_sqr(&y2, &a->y);
+    secp256k1_fe_t x3; secp256k1_fe_sqr(&x3, &a->x); secp256k1_fe_mul(&x3, &x3, &a->x);
+    secp256k1_fe_t z2; secp256k1_fe_sqr(&z2, &a->z);
+    secp256k1_fe_t z6; secp256k1_fe_sqr(&z6, &z2); secp256k1_fe_mul(&z6, &z6, &z2);
+    secp256k1_fe_mul_int(&z6, 7);
+    secp256k1_fe_add(&x3, &z6);
+    secp256k1_fe_normalize(&y2);
+    secp256k1_fe_normalize(&x3);
+    return secp256k1_fe_equal(&y2, &x3);
+}
+
+int static secp256k1_ge_is_valid(const secp256k1_ge_t *a) {
+    if (a->infinity)
+        return 0;
+    // y^2 = x^3 + 7
+    secp256k1_fe_t y2; secp256k1_fe_sqr(&y2, &a->y);
+    secp256k1_fe_t x3; secp256k1_fe_sqr(&x3, &a->x); secp256k1_fe_mul(&x3, &x3, &a->x);
+    secp256k1_fe_t c; secp256k1_fe_set_int(&c, 7);
+    secp256k1_fe_add(&x3, &c);
+    secp256k1_fe_normalize(&y2);
+    secp256k1_fe_normalize(&x3);
+    return secp256k1_fe_equal(&y2, &x3);
+}
+
+void static secp256k1_gej_double(secp256k1_gej_t *r, const secp256k1_gej_t *a) {
+    secp256k1_fe_t t5 = a->y;
+    secp256k1_fe_normalize(&t5);
+    if (a->infinity || secp256k1_fe_is_zero(&t5)) {
+        r->infinity = 1;
+        return;
+    }
+
+    secp256k1_fe_t t1,t2,t3,t4;
+    secp256k1_fe_mul(&r->z, &t5, &a->z);
+    secp256k1_fe_mul_int(&r->z, 2);       // Z' = 2*Y*Z (2)
+    secp256k1_fe_sqr(&t1, &a->x);
+    secp256k1_fe_mul_int(&t1, 3);         // T1 = 3*X^2 (3)
+    secp256k1_fe_sqr(&t2, &t1);           // T2 = 9*X^4 (1)
+    secp256k1_fe_sqr(&t3, &t5);
+    secp256k1_fe_mul_int(&t3, 2);         // T3 = 2*Y^2 (2)
+    secp256k1_fe_sqr(&t4, &t3);
+    secp256k1_fe_mul_int(&t4, 2);         // T4 = 8*Y^4 (2)
+    secp256k1_fe_mul(&t3, &a->x, &t3);    // T3 = 2*X*Y^2 (1)
+    r->x = t3;
+    secp256k1_fe_mul_int(&r->x, 4);       // X' = 8*X*Y^2 (4)
+    secp256k1_fe_negate(&r->x, &r->x, 4); // X' = -8*X*Y^2 (5)
+    secp256k1_fe_add(&r->x, &t2);         // X' = 9*X^4 - 8*X*Y^2 (6)
+    secp256k1_fe_negate(&t2, &t2, 1);     // T2 = -9*X^4 (2)
+    secp256k1_fe_mul_int(&t3, 6);         // T3 = 12*X*Y^2 (6)
+    secp256k1_fe_add(&t3, &t2);           // T3 = 12*X*Y^2 - 9*X^4 (8)
+    secp256k1_fe_mul(&r->y, &t1, &t3);    // Y' = 36*X^3*Y^2 - 27*X^6 (1)
+    secp256k1_fe_negate(&t2, &t4, 2);     // T2 = -8*Y^4 (3)
+    secp256k1_fe_add(&r->y, &t2);         // Y' = 36*X^3*Y^2 - 27*X^6 - 8*Y^4 (4)
+    r->infinity = 0;
+}
+
+void static secp256k1_gej_add(secp256k1_gej_t *r, const secp256k1_gej_t *a, const secp256k1_gej_t *b) {
+    if (a->infinity) {
+        *r = *b;
+        return;
+    }
+    if (b->infinity) {
+        *r = *a;
+        return;
+    }
+    r->infinity = 0;
+    secp256k1_fe_t z22; secp256k1_fe_sqr(&z22, &b->z);
+    secp256k1_fe_t z12; secp256k1_fe_sqr(&z12, &a->z);
+    secp256k1_fe_t u1; secp256k1_fe_mul(&u1, &a->x, &z22);
+    secp256k1_fe_t u2; secp256k1_fe_mul(&u2, &b->x, &z12);
+    secp256k1_fe_t s1; secp256k1_fe_mul(&s1, &a->y, &z22); secp256k1_fe_mul(&s1, &s1, &b->z);
+    secp256k1_fe_t s2; secp256k1_fe_mul(&s2, &b->y, &z12); secp256k1_fe_mul(&s2, &s2, &a->z);
+    secp256k1_fe_normalize(&u1);
+    secp256k1_fe_normalize(&u2);
+    if (secp256k1_fe_equal(&u1, &u2)) {
+        secp256k1_fe_normalize(&s1);
+        secp256k1_fe_normalize(&s2);
+        if (secp256k1_fe_equal(&s1, &s2)) {
+            secp256k1_gej_double(r, a);
+        } else {
+            r->infinity = 1;
+        }
+        return;
+    }
+    secp256k1_fe_t h; secp256k1_fe_negate(&h, &u1, 1); secp256k1_fe_add(&h, &u2);
+    secp256k1_fe_t i; secp256k1_fe_negate(&i, &s1, 1); secp256k1_fe_add(&i, &s2);
+    secp256k1_fe_t i2; secp256k1_fe_sqr(&i2, &i);
+    secp256k1_fe_t h2; secp256k1_fe_sqr(&h2, &h);
+    secp256k1_fe_t h3; secp256k1_fe_mul(&h3, &h, &h2);
+    secp256k1_fe_mul(&r->z, &a->z, &b->z); secp256k1_fe_mul(&r->z, &r->z, &h);
+    secp256k1_fe_t t; secp256k1_fe_mul(&t, &u1, &h2);
+    r->x = t; secp256k1_fe_mul_int(&r->x, 2); secp256k1_fe_add(&r->x, &h3); secp256k1_fe_negate(&r->x, &r->x, 3); secp256k1_fe_add(&r->x, &i2);
+    secp256k1_fe_negate(&r->y, &r->x, 5); secp256k1_fe_add(&r->y, &t); secp256k1_fe_mul(&r->y, &r->y, &i);
+    secp256k1_fe_mul(&h3, &h3, &s1); secp256k1_fe_negate(&h3, &h3, 1);
+    secp256k1_fe_add(&r->y, &h3);
+}
+
+void static secp256k1_gej_add_ge(secp256k1_gej_t *r, const secp256k1_gej_t *a, const secp256k1_ge_t *b) {
+    if (a->infinity) {
+        r->infinity = b->infinity;
+        r->x = b->x;
+        r->y = b->y;
+        secp256k1_fe_set_int(&r->z, 1);
+        return;
+    }
+    if (b->infinity) {
+        *r = *a;
+        return;
+    }
+    r->infinity = 0;
+    secp256k1_fe_t z12; secp256k1_fe_sqr(&z12, &a->z);
+    secp256k1_fe_t u1 = a->x; secp256k1_fe_normalize(&u1);
+    secp256k1_fe_t u2; secp256k1_fe_mul(&u2, &b->x, &z12);
+    secp256k1_fe_t s1 = a->y; secp256k1_fe_normalize(&s1);
+    secp256k1_fe_t s2; secp256k1_fe_mul(&s2, &b->y, &z12); secp256k1_fe_mul(&s2, &s2, &a->z);
+    secp256k1_fe_normalize(&u1);
+    secp256k1_fe_normalize(&u2);
+    if (secp256k1_fe_equal(&u1, &u2)) {
+        secp256k1_fe_normalize(&s1);
+        secp256k1_fe_normalize(&s2);
+        if (secp256k1_fe_equal(&s1, &s2)) {
+            secp256k1_gej_double(r, a);
+        } else {
+            r->infinity = 1;
+        }
+        return;
+    }
+    secp256k1_fe_t h; secp256k1_fe_negate(&h, &u1, 1); secp256k1_fe_add(&h, &u2);
+    secp256k1_fe_t i; secp256k1_fe_negate(&i, &s1, 1); secp256k1_fe_add(&i, &s2);
+    secp256k1_fe_t i2; secp256k1_fe_sqr(&i2, &i);
+    secp256k1_fe_t h2; secp256k1_fe_sqr(&h2, &h);
+    secp256k1_fe_t h3; secp256k1_fe_mul(&h3, &h, &h2);
+    r->z = a->z; secp256k1_fe_mul(&r->z, &r->z, &h);
+    secp256k1_fe_t t; secp256k1_fe_mul(&t, &u1, &h2);
+    r->x = t; secp256k1_fe_mul_int(&r->x, 2); secp256k1_fe_add(&r->x, &h3); secp256k1_fe_negate(&r->x, &r->x, 3); secp256k1_fe_add(&r->x, &i2);
+    secp256k1_fe_negate(&r->y, &r->x, 5); secp256k1_fe_add(&r->y, &t); secp256k1_fe_mul(&r->y, &r->y, &i);
+    secp256k1_fe_mul(&h3, &h3, &s1); secp256k1_fe_negate(&h3, &h3, 1);
+    secp256k1_fe_add(&r->y, &h3);
+}
+
+void static secp256k1_gej_get_hex(char *r, int *rlen, const secp256k1_gej_t *a) {
+    secp256k1_gej_t c = *a;
+    secp256k1_ge_t t; secp256k1_ge_set_gej(&t, &c);
+    secp256k1_ge_get_hex(r, rlen, &t);
+}
+
+#ifdef USE_ENDOMORPHISM
+void static secp256k1_gej_mul_lambda(secp256k1_gej_t *r, const secp256k1_gej_t *a) {
+    const secp256k1_fe_t *beta = &secp256k1_ge_consts->beta;
+    *r = *a;
+    secp256k1_fe_mul(&r->x, &r->x, beta);
+}
+
+void static secp256k1_gej_split_exp(secp256k1_num_t *r1, secp256k1_num_t *r2, const secp256k1_num_t *a) {
+    const secp256k1_ge_consts_t *c = secp256k1_ge_consts;
+    secp256k1_num_t bnc1, bnc2, bnt1, bnt2, bnn2;
+
+    secp256k1_num_init(&bnc1);
+    secp256k1_num_init(&bnc2);
+    secp256k1_num_init(&bnt1);
+    secp256k1_num_init(&bnt2);
+    secp256k1_num_init(&bnn2);
+
+    secp256k1_num_copy(&bnn2, &c->order);
+    secp256k1_num_shift(&bnn2, 1);
+
+    secp256k1_num_mul(&bnc1, a, &c->a1b2);
+    secp256k1_num_add(&bnc1, &bnc1, &bnn2);
+    secp256k1_num_div(&bnc1, &bnc1, &c->order);
+
+    secp256k1_num_mul(&bnc2, a, &c->b1);
+    secp256k1_num_add(&bnc2, &bnc2, &bnn2);
+    secp256k1_num_div(&bnc2, &bnc2, &c->order);
+
+    secp256k1_num_mul(&bnt1, &bnc1, &c->a1b2);
+    secp256k1_num_mul(&bnt2, &bnc2, &c->a2);
+    secp256k1_num_add(&bnt1, &bnt1, &bnt2);
+    secp256k1_num_sub(r1, a, &bnt1);
+    secp256k1_num_mul(&bnt1, &bnc1, &c->b1);
+    secp256k1_num_mul(&bnt2, &bnc2, &c->a1b2);
+    secp256k1_num_sub(r2, &bnt1, &bnt2);
+
+    secp256k1_num_free(&bnc1);
+    secp256k1_num_free(&bnc2);
+    secp256k1_num_free(&bnt1);
+    secp256k1_num_free(&bnt2);
+    secp256k1_num_free(&bnn2);
+}
+#endif
+
+
+void static secp256k1_ge_start(void) {
+    static const unsigned char secp256k1_ge_consts_order[] = {
+        0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,
+        0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFE,
+        0xBA,0xAE,0xDC,0xE6,0xAF,0x48,0xA0,0x3B,
+        0xBF,0xD2,0x5E,0x8C,0xD0,0x36,0x41,0x41
+    };
+    static const unsigned char secp256k1_ge_consts_g_x[] = {
+        0x79,0xBE,0x66,0x7E,0xF9,0xDC,0xBB,0xAC,
+        0x55,0xA0,0x62,0x95,0xCE,0x87,0x0B,0x07,
+        0x02,0x9B,0xFC,0xDB,0x2D,0xCE,0x28,0xD9,
+        0x59,0xF2,0x81,0x5B,0x16,0xF8,0x17,0x98
+    };
+    static const unsigned char secp256k1_ge_consts_g_y[] = {
+        0x48,0x3A,0xDA,0x77,0x26,0xA3,0xC4,0x65,
+        0x5D,0xA4,0xFB,0xFC,0x0E,0x11,0x08,0xA8,
+        0xFD,0x17,0xB4,0x48,0xA6,0x85,0x54,0x19,
+        0x9C,0x47,0xD0,0x8F,0xFB,0x10,0xD4,0xB8
+    };
+#ifdef USE_ENDOMORPHISM
+    // properties of secp256k1's efficiently computable endomorphism
+    static const unsigned char secp256k1_ge_consts_lambda[] = {
+        0x53,0x63,0xad,0x4c,0xc0,0x5c,0x30,0xe0,
+        0xa5,0x26,0x1c,0x02,0x88,0x12,0x64,0x5a,
+        0x12,0x2e,0x22,0xea,0x20,0x81,0x66,0x78,
+        0xdf,0x02,0x96,0x7c,0x1b,0x23,0xbd,0x72
+    };
+    static const unsigned char secp256k1_ge_consts_beta[] = {
+        0x7a,0xe9,0x6a,0x2b,0x65,0x7c,0x07,0x10,
+        0x6e,0x64,0x47,0x9e,0xac,0x34,0x34,0xe9,
+        0x9c,0xf0,0x49,0x75,0x12,0xf5,0x89,0x95,
+        0xc1,0x39,0x6c,0x28,0x71,0x95,0x01,0xee
+    };
+    static const unsigned char secp256k1_ge_consts_a1b2[] = {
+        0x30,0x86,0xd2,0x21,0xa7,0xd4,0x6b,0xcd,
+        0xe8,0x6c,0x90,0xe4,0x92,0x84,0xeb,0x15
+    };
+    static const unsigned char secp256k1_ge_consts_b1[] = {
+        0xe4,0x43,0x7e,0xd6,0x01,0x0e,0x88,0x28,
+        0x6f,0x54,0x7f,0xa9,0x0a,0xbf,0xe4,0xc3
+    };
+    static const unsigned char secp256k1_ge_consts_a2[] = {
+        0x01,
+        0x14,0xca,0x50,0xf7,0xa8,0xe2,0xf3,0xf6,
+        0x57,0xc1,0x10,0x8d,0x9d,0x44,0xcf,0xd8
+    };
+#endif
+    if (secp256k1_ge_consts == NULL) {
+        secp256k1_ge_consts_t *ret = (secp256k1_ge_consts_t*)malloc(sizeof(secp256k1_ge_consts_t));
+        secp256k1_num_init(&ret->order);
+        secp256k1_num_init(&ret->half_order);
+        secp256k1_num_set_bin(&ret->order,  secp256k1_ge_consts_order,  sizeof(secp256k1_ge_consts_order));
+        secp256k1_num_copy(&ret->half_order, &ret->order);
+        secp256k1_num_shift(&ret->half_order, 1);
+#ifdef USE_ENDOMORPHISM
+        secp256k1_num_init(&ret->lambda);
+        secp256k1_num_init(&ret->a1b2);
+        secp256k1_num_init(&ret->a2);
+        secp256k1_num_init(&ret->b1);
+        secp256k1_num_set_bin(&ret->lambda, secp256k1_ge_consts_lambda, sizeof(secp256k1_ge_consts_lambda));
+        secp256k1_num_set_bin(&ret->a1b2,   secp256k1_ge_consts_a1b2,   sizeof(secp256k1_ge_consts_a1b2));
+        secp256k1_num_set_bin(&ret->a2,     secp256k1_ge_consts_a2,     sizeof(secp256k1_ge_consts_a2));
+        secp256k1_num_set_bin(&ret->b1,     secp256k1_ge_consts_b1,     sizeof(secp256k1_ge_consts_b1));
+        secp256k1_fe_set_b32(&ret->beta, secp256k1_ge_consts_beta);
+#endif
+        secp256k1_fe_t g_x, g_y;
+        secp256k1_fe_set_b32(&g_x, secp256k1_ge_consts_g_x);
+        secp256k1_fe_set_b32(&g_y, secp256k1_ge_consts_g_y);
+        secp256k1_ge_set_xy(&ret->g, &g_x, &g_y);
+        secp256k1_ge_consts = ret;
+    }
+}
+
+void static secp256k1_ge_stop(void) {
+    if (secp256k1_ge_consts != NULL) {
+        secp256k1_ge_consts_t *c = (secp256k1_ge_consts_t*)secp256k1_ge_consts;
+        secp256k1_num_free(&c->order);
+        secp256k1_num_free(&c->half_order);
+        secp256k1_num_free(&c->lambda);
+        secp256k1_num_free(&c->a1b2);
+        secp256k1_num_free(&c->a2);
+        secp256k1_num_free(&c->b1);
+        free((void*)c);
+        secp256k1_ge_consts = NULL;
+    }
+}
+
+#endif
diff --git a/secp256k1/impl/num.h b/secp256k1/impl/num.h
new file mode 100644
index 000000000..fc6d05c3d
--- /dev/null
+++ b/secp256k1/impl/num.h
@@ -0,0 +1,18 @@
+// Copyright (c) 2013 Pieter Wuille
+// Distributed under the MIT/X11 software license, see the accompanying
+// file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
+#ifndef _SECP256K1_NUM_IMPL_H_
+#define _SECP256K1_NUM_IMPL_H_
+
+#include "../num.h"
+
+#if defined(USE_NUM_GMP)
+#include "num_gmp.h"
+#elif defined(USE_NUM_OPENSSL)
+#include "num_openssl.h"
+#else
+#error "Please select num implementation"
+#endif
+
+#endif
diff --git a/secp256k1/impl/num_gmp.h b/secp256k1/impl/num_gmp.h
new file mode 100644
index 000000000..75ef9dcf6
--- /dev/null
+++ b/secp256k1/impl/num_gmp.h
@@ -0,0 +1,346 @@
+// Copyright (c) 2013 Pieter Wuille
+// Distributed under the MIT/X11 software license, see the accompanying
+// file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
+#ifndef _SECP256K1_NUM_REPR_IMPL_H_
+#define _SECP256K1_NUM_REPR_IMPL_H_
+
+#include <assert.h>
+#include <string.h>
+#include <stdlib.h>
+#include <gmp.h>
+
+#include "num.h"
+
+#ifdef VERIFY
+void static secp256k1_num_sanity(const secp256k1_num_t *a) {
+    assert(a->limbs == 1 || (a->limbs > 1 && a->data[a->limbs-1] != 0));
+}
+#else
+#define secp256k1_num_sanity(a) do { } while(0)
+#endif
+
+void static secp256k1_num_init(secp256k1_num_t *r) {
+    r->neg = 0;
+    r->limbs = 1;
+    r->data[0] = 0;
+}
+
+void static secp256k1_num_free(secp256k1_num_t *r) {
+}
+
+void static secp256k1_num_copy(secp256k1_num_t *r, const secp256k1_num_t *a) {
+    *r = *a;
+}
+
+int static secp256k1_num_bits(const secp256k1_num_t *a) {
+    int ret=(a->limbs-1)*GMP_NUMB_BITS;
+    mp_limb_t x=a->data[a->limbs-1];
+    while (x) {
+        x >>= 1;
+        ret++;
+    }
+    return ret;
+}
+
+
+void static secp256k1_num_get_bin(unsigned char *r, unsigned int rlen, const secp256k1_num_t *a) {
+    unsigned char tmp[65];
+    int len = 0;
+    if (a->limbs>1 || a->data[0] != 0) {
+        len = mpn_get_str(tmp, 256, (mp_limb_t*)a->data, a->limbs);
+    }
+    int shift = 0;
+    while (shift < len && tmp[shift] == 0) shift++;
+    assert(len-shift <= rlen);
+    memset(r, 0, rlen - len + shift);
+    if (len > shift)
+        memcpy(r + rlen - len + shift, tmp + shift, len - shift);
+}
+
+void static secp256k1_num_set_bin(secp256k1_num_t *r, const unsigned char *a, unsigned int alen) {
+    assert(alen > 0);
+    assert(alen <= 64);
+    int len = mpn_set_str(r->data, a, alen, 256);
+    assert(len <= NUM_LIMBS*2);
+    r->limbs = len;
+    r->neg = 0;
+    while (r->limbs > 1 && r->data[r->limbs-1]==0) r->limbs--;
+}
+
+void static secp256k1_num_set_int(secp256k1_num_t *r, int a) {
+    r->limbs = 1;
+    r->neg = (a < 0);
+    r->data[0] = (a < 0) ? -a : a;
+}
+
+void static secp256k1_num_add_abs(secp256k1_num_t *r, const secp256k1_num_t *a, const secp256k1_num_t *b) {
+    mp_limb_t c = mpn_add(r->data, a->data, a->limbs, b->data, b->limbs);
+    r->limbs = a->limbs;
+    if (c != 0) {
+        assert(r->limbs < 2*NUM_LIMBS);
+        r->data[r->limbs++] = c;
+    }
+}
+
+void static secp256k1_num_sub_abs(secp256k1_num_t *r, const secp256k1_num_t *a, const secp256k1_num_t *b) {
+    mp_limb_t c = mpn_sub(r->data, a->data, a->limbs, b->data, b->limbs);
+    assert(c == 0);
+    r->limbs = a->limbs;
+    while (r->limbs > 1 && r->data[r->limbs-1]==0) r->limbs--;
+}
+
+void static secp256k1_num_mod(secp256k1_num_t *r, const secp256k1_num_t *m) {
+    secp256k1_num_sanity(r);
+    secp256k1_num_sanity(m);
+
+    if (r->limbs >= m->limbs) {
+        mp_limb_t t[2*NUM_LIMBS];
+        mpn_tdiv_qr(t, r->data, 0, r->data, r->limbs, m->data, m->limbs);
+        r->limbs = m->limbs;
+        while (r->limbs > 1 && r->data[r->limbs-1]==0) r->limbs--;
+    }
+
+    if (r->neg && (r->limbs > 1 || r->data[0] != 0)) {
+        secp256k1_num_sub_abs(r, m, r);
+        r->neg = 0;
+    }
+}
+
+void static secp256k1_num_mod_inverse(secp256k1_num_t *r, const secp256k1_num_t *a, const secp256k1_num_t *m) {
+    secp256k1_num_sanity(a);
+    secp256k1_num_sanity(m);
+
+    // mpn_gcdext computes: (G,S) = gcdext(U,V), where
+    // * G = gcd(U,V)
+    // * G = U*S + V*T
+    // * U has equal or more limbs than V, and V has no padding
+    // If we set U to be (a padded version of) a, and V = m:
+    //   G = a*S + m*T
+    //   G = a*S mod m
+    // Assuming G=1:
+    //   S = 1/a mod m
+    assert(m->limbs <= NUM_LIMBS);
+    assert(m->data[m->limbs-1] != 0);
+    mp_limb_t g[NUM_LIMBS+1];
+    mp_limb_t u[NUM_LIMBS+1];
+    mp_limb_t v[NUM_LIMBS+1];
+    for (int i=0; i < m->limbs; i++) {
+        u[i] = (i < a->limbs) ? a->data[i] : 0;
+        v[i] = m->data[i];
+    }
+    mp_size_t sn = NUM_LIMBS+1;
+    mp_size_t gn = mpn_gcdext(g, r->data, &sn, u, m->limbs, v, m->limbs);
+    assert(gn == 1);
+    assert(g[0] == 1);
+    r->neg = a->neg ^ m->neg;
+    if (sn < 0) {
+        mpn_sub(r->data, m->data, m->limbs, r->data, -sn);
+        r->limbs = m->limbs;
+        while (r->limbs > 1 && r->data[r->limbs-1]==0) r->limbs--;
+    } else {
+        r->limbs = sn;
+    }
+}
+
+int static secp256k1_num_is_zero(const secp256k1_num_t *a) {
+    return (a->limbs == 1 && a->data[0] == 0);
+}
+
+int static secp256k1_num_is_odd(const secp256k1_num_t *a) {
+    return a->data[0] & 1;
+}
+
+int static secp256k1_num_is_neg(const secp256k1_num_t *a) {
+    return (a->limbs > 1 || a->data[0] != 0) && a->neg;
+}
+
+int static secp256k1_num_cmp(const secp256k1_num_t *a, const secp256k1_num_t *b) {
+    if (a->limbs > b->limbs) return 1;
+    if (a->limbs < b->limbs) return -1;
+    return mpn_cmp(a->data, b->data, a->limbs);
+}
+
+void static secp256k1_num_subadd(secp256k1_num_t *r, const secp256k1_num_t *a, const secp256k1_num_t *b, int bneg) {
+    if (!(b->neg ^ bneg ^ a->neg)) { // a and b have the same sign
+        r->neg = a->neg;
+        if (a->limbs >= b->limbs) {
+            secp256k1_num_add_abs(r, a, b);
+        } else {
+            secp256k1_num_add_abs(r, b, a);
+        }
+    } else {
+        if (secp256k1_num_cmp(a, b) > 0) {
+            r->neg = a->neg;
+            secp256k1_num_sub_abs(r, a, b);
+        } else {
+            r->neg = b->neg ^ bneg;
+            secp256k1_num_sub_abs(r, b, a);
+        }
+    }
+}
+
+void static secp256k1_num_add(secp256k1_num_t *r, const secp256k1_num_t *a, const secp256k1_num_t *b) {
+    secp256k1_num_sanity(a);
+    secp256k1_num_sanity(b);
+    secp256k1_num_subadd(r, a, b, 0);
+}
+
+void static secp256k1_num_sub(secp256k1_num_t *r, const secp256k1_num_t *a, const secp256k1_num_t *b) {
+    secp256k1_num_sanity(a);
+    secp256k1_num_sanity(b);
+    secp256k1_num_subadd(r, a, b, 1);
+}
+
+void static secp256k1_num_mul(secp256k1_num_t *r, const secp256k1_num_t *a, const secp256k1_num_t *b) {
+    secp256k1_num_sanity(a);
+    secp256k1_num_sanity(b);
+
+    mp_limb_t tmp[2*NUM_LIMBS+1];
+    assert(a->limbs + b->limbs <= 2*NUM_LIMBS+1);
+    if ((a->limbs==1 && a->data[0]==0) || (b->limbs==1 && b->data[0]==0)) {
+        r->limbs = 1;
+        r->neg = 0;
+        r->data[0] = 0;
+        return;
+    }
+    if (a->limbs >= b->limbs)
+        mpn_mul(tmp, a->data, a->limbs, b->data, b->limbs);
+    else
+        mpn_mul(tmp, b->data, b->limbs, a->data, a->limbs);
+    r->limbs = a->limbs + b->limbs;
+    if (r->limbs > 1 && tmp[r->limbs - 1]==0) r->limbs--;
+    assert(r->limbs <= 2*NUM_LIMBS);
+    mpn_copyi(r->data, tmp, r->limbs);
+    r->neg = a->neg ^ b->neg;
+}
+
+void static secp256k1_num_div(secp256k1_num_t *r, const secp256k1_num_t *a, const secp256k1_num_t *b) {
+    secp256k1_num_sanity(a);
+    secp256k1_num_sanity(b);
+    if (b->limbs > a->limbs) {
+        r->limbs = 1;
+        r->data[0] = 0;
+        r->neg = 0;
+        return;
+    }
+
+    mp_limb_t quo[2*NUM_LIMBS+1];
+    mp_limb_t rem[2*NUM_LIMBS+1];
+    mpn_tdiv_qr(quo, rem, 0, a->data, a->limbs, b->data, b->limbs);
+    mpn_copyi(r->data, quo, a->limbs - b->limbs + 1);
+    r->limbs = a->limbs - b->limbs + 1;
+    while (r->limbs > 1 && r->data[r->limbs - 1]==0) r->limbs--;
+    r->neg = a->neg ^ b->neg;
+}
+
+void static secp256k1_num_mod_mul(secp256k1_num_t *r, const secp256k1_num_t *a, const secp256k1_num_t *b, const secp256k1_num_t *m) {
+    secp256k1_num_mul(r, a, b);
+    secp256k1_num_mod(r, m);
+}
+
+
+int static secp256k1_num_shift(secp256k1_num_t *r, int bits) {
+    assert(bits <= GMP_NUMB_BITS);
+    mp_limb_t ret = mpn_rshift(r->data, r->data, r->limbs, bits);
+    if (r->limbs>1 && r->data[r->limbs-1]==0) r->limbs--;
+    ret >>= (GMP_NUMB_BITS - bits);
+    return ret;
+}
+
+int static secp256k1_num_get_bit(const secp256k1_num_t *a, int pos) {
+    return (a->limbs*GMP_NUMB_BITS > pos) && ((a->data[pos/GMP_NUMB_BITS] >> (pos % GMP_NUMB_BITS)) & 1);
+}
+
+void static secp256k1_num_inc(secp256k1_num_t *r) {
+    mp_limb_t ret = mpn_add_1(r->data, r->data, r->limbs, (mp_limb_t)1);
+    if (ret) {
+        assert(r->limbs < 2*NUM_LIMBS);
+        r->data[r->limbs++] = ret;
+    }
+}
+
+void static secp256k1_num_set_hex(secp256k1_num_t *r, const char *a, int alen) {
+    static const unsigned char cvt[256] = {
+        0, 0, 0, 0, 0, 0, 0,0,0,0,0,0,0,0,0,0,
+        0, 0, 0, 0, 0, 0, 0,0,0,0,0,0,0,0,0,0,
+        0, 0, 0, 0, 0, 0, 0,0,0,0,0,0,0,0,0,0,
+        0, 1, 2, 3, 4, 5, 6,7,8,9,0,0,0,0,0,0,
+        0,10,11,12,13,14,15,0,0,0,0,0,0,0,0,0,
+        0, 0, 0, 0, 0, 0, 0,0,0,0,0,0,0,0,0,0,
+        0,10,11,12,13,14,15,0,0,0,0,0,0,0,0,0,
+        0, 0, 0, 0, 0, 0, 0,0,0,0,0,0,0,0,0,0,
+        0, 0, 0, 0, 0, 0, 0,0,0,0,0,0,0,0,0,0,
+        0, 0, 0, 0, 0, 0, 0,0,0,0,0,0,0,0,0,0,
+        0, 0, 0, 0, 0, 0, 0,0,0,0,0,0,0,0,0,0,
+        0, 0, 0, 0, 0, 0, 0,0,0,0,0,0,0,0,0,0,
+        0, 0, 0, 0, 0, 0, 0,0,0,0,0,0,0,0,0,0,
+        0, 0, 0, 0, 0, 0, 0,0,0,0,0,0,0,0,0,0,
+        0, 0, 0, 0, 0, 0, 0,0,0,0,0,0,0,0,0,0,
+        0, 0, 0, 0, 0, 0, 0,0,0,0,0,0,0,0,0,0
+    };
+    char num[257] = {};
+    for (int i=0; i<alen; i++) {
+        num[i] = cvt[a[i]];
+    }
+    r->limbs = mpn_set_str(r->data, num, alen, 16);
+    while (r->limbs > 1 && r->data[r->limbs-1] == 0) r->limbs--;
+}
+
+void static secp256k1_num_get_hex(char *r, int rlen, const secp256k1_num_t *a) {
+    static const unsigned char cvt[16] = {'0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'A', 'B', 'C', 'D', 'E', 'F'};
+    unsigned char *tmp = malloc(257);
+    mp_size_t len = mpn_get_str(tmp, 16, (mp_limb_t*)a->data, a->limbs);
+    assert(len <= rlen);
+    for (int i=0; i<len; i++) {
+        assert(rlen-len+i >= 0);
+        assert(rlen-len+i < rlen);
+        assert(tmp[i] >= 0);
+        assert(tmp[i] < 16);
+        r[rlen-len+i] = cvt[tmp[i]];
+    }
+    for (int i=0; i<rlen-len; i++) {
+        assert(i >= 0);
+        assert(i < rlen);
+        r[i] = cvt[0];
+    }
+    free(tmp);
+}
+
+void static secp256k1_num_split(secp256k1_num_t *rl, secp256k1_num_t *rh, const secp256k1_num_t *a, int bits) {
+    assert(bits > 0);
+    rh->neg = a->neg;
+    if (bits >= a->limbs * GMP_NUMB_BITS) {
+        *rl = *a;
+        rh->limbs = 1;
+        rh->data[0] = 0;
+        return;
+    }
+    rl->limbs = 0;
+    rl->neg = a->neg;
+    int left = bits;
+    while (left >= GMP_NUMB_BITS) {
+        rl->data[rl->limbs] = a->data[rl->limbs];
+        rl->limbs++;
+        left -= GMP_NUMB_BITS;
+    }
+    if (left == 0) {
+        mpn_copyi(rh->data, a->data + rl->limbs, a->limbs - rl->limbs);
+        rh->limbs = a->limbs - rl->limbs;
+    } else {
+        mpn_rshift(rh->data, a->data + rl->limbs, a->limbs - rl->limbs, left);
+        rh->limbs = a->limbs - rl->limbs;
+        while (rh->limbs>1 && rh->data[rh->limbs-1]==0) rh->limbs--;
+    }
+    if (left > 0) {
+        rl->data[rl->limbs] = a->data[rl->limbs] & ((((mp_limb_t)1) << left) - 1);
+        rl->limbs++;
+    }
+    while (rl->limbs>1 && rl->data[rl->limbs-1]==0) rl->limbs--;
+}
+
+void static secp256k1_num_negate(secp256k1_num_t *r) {
+    r->neg ^= 1;
+}
+
+#endif
diff --git a/secp256k1/impl/num_openssl.h b/secp256k1/impl/num_openssl.h
new file mode 100644
index 000000000..0a54689ac
--- /dev/null
+++ b/secp256k1/impl/num_openssl.h
@@ -0,0 +1,145 @@
+// Copyright (c) 2013 Pieter Wuille
+// Distributed under the MIT/X11 software license, see the accompanying
+// file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
+#ifndef _SECP256K1_NUM_REPR_IMPL_H_
+#define _SECP256K1_NUM_REPR_IMPL_H_
+
+#include <assert.h>
+#include <string.h>
+#include <stdlib.h>
+#include <openssl/bn.h>
+#include <openssl/crypto.h>
+
+#include "../num.h"
+
+void static secp256k1_num_init(secp256k1_num_t *r) {
+    BN_init(&r->bn);
+}
+
+void static secp256k1_num_free(secp256k1_num_t *r) {
+    BN_free(&r->bn);
+}
+
+void static secp256k1_num_copy(secp256k1_num_t *r, const secp256k1_num_t *a) {
+    BN_copy(&r->bn, &a->bn);
+}
+
+void static secp256k1_num_get_bin(unsigned char *r, unsigned int rlen, const secp256k1_num_t *a) {
+    unsigned int size = BN_num_bytes(&a->bn);
+    assert(size <= rlen);
+    memset(r,0,rlen);
+    BN_bn2bin(&a->bn, r + rlen - size);
+}
+
+void static secp256k1_num_set_bin(secp256k1_num_t *r, const unsigned char *a, unsigned int alen) {
+    BN_bin2bn(a, alen, &r->bn);
+}
+
+void static secp256k1_num_set_int(secp256k1_num_t *r, int a) {
+    BN_set_word(&r->bn, a < 0 ? -a : a);
+    BN_set_negative(&r->bn, a < 0);
+}
+
+void static secp256k1_num_mod_inverse(secp256k1_num_t *r, const secp256k1_num_t *a, const secp256k1_num_t *m) {
+    BN_CTX *ctx = BN_CTX_new();
+    BN_mod_inverse(&r->bn, &a->bn, &m->bn, ctx);
+    BN_CTX_free(ctx);
+}
+
+void static secp256k1_num_mod_mul(secp256k1_num_t *r, const secp256k1_num_t *a, const secp256k1_num_t *b, const secp256k1_num_t *m) {
+    BN_CTX *ctx = BN_CTX_new();
+    BN_mod_mul(&r->bn, &a->bn, &b->bn, &m->bn, ctx);
+    BN_CTX_free(ctx);
+}
+
+int static secp256k1_num_cmp(const secp256k1_num_t *a, const secp256k1_num_t *b) {
+    return BN_cmp(&a->bn, &b->bn);
+}
+
+void static secp256k1_num_add(secp256k1_num_t *r, const secp256k1_num_t *a, const secp256k1_num_t *b) {
+    BN_add(&r->bn, &a->bn, &b->bn);
+}
+
+void static secp256k1_num_sub(secp256k1_num_t *r, const secp256k1_num_t *a, const secp256k1_num_t *b) {
+    BN_sub(&r->bn, &a->bn, &b->bn);
+}
+
+void static secp256k1_num_mul(secp256k1_num_t *r, const secp256k1_num_t *a, const secp256k1_num_t *b) {
+    BN_CTX *ctx = BN_CTX_new();
+    BN_mul(&r->bn, &a->bn, &b->bn, ctx);
+    BN_CTX_free(ctx);
+}
+
+void static secp256k1_num_div(secp256k1_num_t *r, const secp256k1_num_t *a, const secp256k1_num_t *b) {
+    BN_CTX *ctx = BN_CTX_new();
+    BN_div(&r->bn, NULL, &a->bn, &b->bn, ctx);
+    BN_CTX_free(ctx);
+}
+
+void static secp256k1_num_mod(secp256k1_num_t *r, const secp256k1_num_t *m) {
+    BN_CTX *ctx = BN_CTX_new();
+    BN_nnmod(&r->bn, &r->bn, &m->bn, ctx);
+    BN_CTX_free(ctx);
+}
+
+int static secp256k1_num_bits(const secp256k1_num_t *a) {
+    return BN_num_bits(&a->bn);
+}
+
+int static secp256k1_num_shift(secp256k1_num_t *r, int bits) {
+    int ret = BN_is_zero(&r->bn) ? 0 : r->bn.d[0] & ((1 << bits) - 1);
+    BN_rshift(&r->bn, &r->bn, bits);
+    return ret;
+}
+
+int static secp256k1_num_is_zero(const secp256k1_num_t *a) {
+    return BN_is_zero(&a->bn);
+}
+
+int static secp256k1_num_is_odd(const secp256k1_num_t *a) {
+    return BN_is_odd(&a->bn);
+}
+
+int static secp256k1_num_is_neg(const secp256k1_num_t *a) {
+    return BN_is_negative(&a->bn);
+}
+
+int static secp256k1_num_get_bit(const secp256k1_num_t *a, int pos) {
+    return BN_is_bit_set(&a->bn, pos);
+}
+
+void static secp256k1_num_inc(secp256k1_num_t *r) {
+    BN_add_word(&r->bn, 1);
+}
+
+void static secp256k1_num_set_hex(secp256k1_num_t *r, const char *a, int alen) {
+    char *str = (char*)malloc(alen+1);
+    memcpy(str, a, alen);
+    str[alen] = 0;
+    BIGNUM *pbn = &r->bn;
+    BN_hex2bn(&pbn, str);
+    free(str);
+}
+
+void static secp256k1_num_get_hex(char *r, int rlen, const secp256k1_num_t *a) {
+    char *str = BN_bn2hex(&a->bn);
+    int len = strlen(str);
+    assert(rlen >= len);
+    for (int i=0; i<rlen-len; i++)
+        r[i] = '0';
+    memcpy(r+rlen-len, str, len);
+    OPENSSL_free(str);
+}
+
+void static secp256k1_num_split(secp256k1_num_t *rl, secp256k1_num_t *rh, const secp256k1_num_t *a, int bits) {
+    BN_copy(&rl->bn, &a->bn);
+    BN_rshift(&rh->bn, &a->bn, bits);
+    BN_mask_bits(&rl->bn, bits);
+}
+
+void static secp256k1_num_negate(secp256k1_num_t *r) {
+    BN_set_negative(&r->bn, !BN_is_negative(&r->bn));
+}
+
+#endif
diff --git a/secp256k1/impl/util.h b/secp256k1/impl/util.h
new file mode 100644
index 000000000..a59a00cac
--- /dev/null
+++ b/secp256k1/impl/util.h
@@ -0,0 +1,45 @@
+// Copyright (c) 2013 Pieter Wuille
+// Distributed under the MIT/X11 software license, see the accompanying
+// file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
+#ifndef _SECP256K1_UTIL_IMPL_H_
+#define _SECP256K1_UTIL_IMPL_H_
+
+#include <stdint.h>
+#include <string.h>
+
+#include "../util.h"
+
+static inline uint32_t secp256k1_rand32(void) {
+    static uint32_t Rz = 11, Rw = 11;
+    Rz = 36969 * (Rz & 0xFFFF) + (Rz >> 16);
+    Rw = 18000 * (Rw & 0xFFFF) + (Rw >> 16);
+    return (Rw << 16) + (Rw >> 16) + Rz;
+}
+
+static void secp256k1_rand256(unsigned char *b32) {
+    for (int i=0; i<8; i++) {
+        uint32_t r = secp256k1_rand32();
+        b32[i*4 + 0] = (r >>  0) & 0xFF;
+        b32[i*4 + 1] = (r >>  8) & 0xFF;
+        b32[i*4 + 2] = (r >> 16) & 0xFF;
+        b32[i*4 + 3] = (r >> 24) & 0xFF;
+    }
+}
+
+static void secp256k1_rand256_test(unsigned char *b32) {
+    int bits=0;
+    memset(b32, 0, 32);
+    while (bits < 256) {
+        uint32_t ent = secp256k1_rand32();
+        int now = 1 + ((ent % 64)*((ent >> 6) % 32)+16)/31;
+        uint32_t val = 1 & (ent >> 11);
+        while (now > 0 && bits < 256) {
+            b32[bits / 8] |= val << (bits % 8);
+            now--;
+            bits++;
+        }
+    }
+}
+
+#endif
diff --git a/secp256k1/num.h b/secp256k1/num.h
new file mode 100644
index 000000000..b2e7462bc
--- /dev/null
+++ b/secp256k1/num.h
@@ -0,0 +1,93 @@
+// Copyright (c) 2013 Pieter Wuille
+// Distributed under the MIT/X11 software license, see the accompanying
+// file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
+#ifndef _SECP256K1_NUM_
+#define _SECP256K1_NUM_
+
+#if defined(USE_NUM_GMP)
+#include "num_gmp.h"
+#elif defined(USE_NUM_OPENSSL)
+#include "num_openssl.h"
+#else
+#error "Please select num implementation"
+#endif
+
+/** Initialize a number. */
+void static secp256k1_num_init(secp256k1_num_t *r);
+
+/** Free a number. */
+void static secp256k1_num_free(secp256k1_num_t *r);
+
+/** Copy a number. */
+void static secp256k1_num_copy(secp256k1_num_t *r, const secp256k1_num_t *a);
+
+/** Convert a number's absolute value to a binary big-endian string.
+ *  There must be enough place. */
+void static secp256k1_num_get_bin(unsigned char *r, unsigned int rlen, const secp256k1_num_t *a);
+
+/** Set a number to the value of a binary big-endian string. */
+void static secp256k1_num_set_bin(secp256k1_num_t *r, const unsigned char *a, unsigned int alen);
+
+/** Set a number equal to a (signed) integer. */
+void static secp256k1_num_set_int(secp256k1_num_t *r, int a);
+
+/** Compute a modular inverse. The input must be less than the modulus. */
+void static secp256k1_num_mod_inverse(secp256k1_num_t *r, const secp256k1_num_t *a, const secp256k1_num_t *m);
+
+/** Multiply two numbers modulo another. */
+void static secp256k1_num_mod_mul(secp256k1_num_t *r, const secp256k1_num_t *a, const secp256k1_num_t *b, const secp256k1_num_t *m);
+
+/** Compare the absolute value of two numbers. */
+int  static secp256k1_num_cmp(const secp256k1_num_t *a, const secp256k1_num_t *b);
+
+/** Add two (signed) numbers. */
+void static secp256k1_num_add(secp256k1_num_t *r, const secp256k1_num_t *a, const secp256k1_num_t *b);
+
+/** Subtract two (signed) numbers. */
+void static secp256k1_num_sub(secp256k1_num_t *r, const secp256k1_num_t *a, const secp256k1_num_t *b);
+
+/** Multiply two (signed) numbers. */
+void static secp256k1_num_mul(secp256k1_num_t *r, const secp256k1_num_t *a, const secp256k1_num_t *b);
+
+/** Divide two (signed) numbers. */
+void static secp256k1_num_div(secp256k1_num_t *r, const secp256k1_num_t *a, const secp256k1_num_t *b);
+
+/** Replace a number by its remainder modulo m. M's sign is ignored. The result is a number between 0 and m-1,
+    even if r was negative. */
+void static secp256k1_num_mod(secp256k1_num_t *r, const secp256k1_num_t *m);
+
+/** Calculate the number of bits in (the absolute value of) a number. */
+int  static secp256k1_num_bits(const secp256k1_num_t *a);
+
+/** Right-shift the passed number by bits bits, and return those bits. */
+int  static secp256k1_num_shift(secp256k1_num_t *r, int bits);
+
+/** Check whether a number is zero. */
+int  static secp256k1_num_is_zero(const secp256k1_num_t *a);
+
+/** Check whether a number is odd. */
+int  static secp256k1_num_is_odd(const secp256k1_num_t *a);
+
+/** Check whether a number is strictly negative. */
+int  static secp256k1_num_is_neg(const secp256k1_num_t *a);
+
+/** Check whether a particular bit is set in a number. */
+int  static secp256k1_num_get_bit(const secp256k1_num_t *a, int pos);
+
+/** Increase a number by 1. */
+void static secp256k1_num_inc(secp256k1_num_t *r);
+
+/** Set a number equal to the value of a hex string (unsigned). */
+void static secp256k1_num_set_hex(secp256k1_num_t *r, const char *a, int alen);
+
+/** Convert (the absolute value of) a number to a hexadecimal string. */
+void static secp256k1_num_get_hex(char *r, int rlen, const secp256k1_num_t *a);
+
+/** Split a number into a low and high part. */
+void static secp256k1_num_split(secp256k1_num_t *rl, secp256k1_num_t *rh, const secp256k1_num_t *a, int bits);
+
+/** Change a number's sign. */
+void static secp256k1_num_negate(secp256k1_num_t *r);
+
+#endif
diff --git a/secp256k1/num_gmp.h b/secp256k1/num_gmp.h
new file mode 100644
index 000000000..960df8605
--- /dev/null
+++ b/secp256k1/num_gmp.h
@@ -0,0 +1,18 @@
+// Copyright (c) 2013 Pieter Wuille
+// Distributed under the MIT/X11 software license, see the accompanying
+// file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
+#ifndef _SECP256K1_NUM_REPR_
+#define _SECP256K1_NUM_REPR_
+
+#include <gmp.h>
+
+#define NUM_LIMBS ((256+GMP_NUMB_BITS-1)/GMP_NUMB_BITS)
+
+typedef struct {
+    mp_limb_t data[2*NUM_LIMBS];
+    int neg;
+    int limbs;
+} secp256k1_num_t;
+
+#endif
diff --git a/secp256k1/num_openssl.h b/secp256k1/num_openssl.h
new file mode 100644
index 000000000..7d03757f6
--- /dev/null
+++ b/secp256k1/num_openssl.h
@@ -0,0 +1,14 @@
+// Copyright (c) 2013 Pieter Wuille
+// Distributed under the MIT/X11 software license, see the accompanying
+// file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
+#ifndef _SECP256K1_NUM_REPR_
+#define _SECP256K1_NUM_REPR_
+
+#include <openssl/bn.h>
+
+typedef struct {
+    BIGNUM bn;
+} secp256k1_num_t;
+
+#endif
diff --git a/secp256k1/secp256k1.c b/secp256k1/secp256k1.c
new file mode 100644
index 000000000..ed8bf2e95
--- /dev/null
+++ b/secp256k1/secp256k1.c
@@ -0,0 +1,269 @@
+// Copyright (c) 2013 Pieter Wuille
+// Distributed under the MIT/X11 software license, see the accompanying
+// file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
+#include "impl/num.h"
+#include "impl/field.h"
+#include "impl/group.h"
+#include "impl/ecmult.h"
+#include "impl/ecdsa.h"
+
+void secp256k1_start(void) {
+    secp256k1_fe_start();
+    secp256k1_ge_start();
+    secp256k1_ecmult_start();
+}
+
+void secp256k1_stop(void) {
+    secp256k1_ecmult_stop();
+    secp256k1_ge_stop();
+    secp256k1_fe_stop();
+}
+
+int secp256k1_ecdsa_verify(const unsigned char *msg, int msglen, const unsigned char *sig, int siglen, const unsigned char *pubkey, int pubkeylen) {
+    int ret = -3;
+    secp256k1_num_t m; 
+    secp256k1_num_init(&m);
+    secp256k1_ecdsa_sig_t s;
+    secp256k1_ecdsa_sig_init(&s);
+    secp256k1_ge_t q;
+    secp256k1_num_set_bin(&m, msg, msglen);
+
+    if (!secp256k1_ecdsa_pubkey_parse(&q, pubkey, pubkeylen)) {
+        ret = -1;
+        goto end;
+    }
+    if (!secp256k1_ecdsa_sig_parse(&s, sig, siglen)) {
+        ret = -2;
+        goto end;
+    }
+    if (!secp256k1_ecdsa_sig_verify(&s, &q, &m)) {
+        ret = 0;
+        goto end;
+    }
+    ret = 1;
+end:
+    secp256k1_ecdsa_sig_free(&s);
+    secp256k1_num_free(&m);
+    return ret;
+}
+
+int secp256k1_ecdsa_sign(const unsigned char *message, int messagelen, unsigned char *signature, int *signaturelen, const unsigned char *seckey, const unsigned char *nonce) {
+    secp256k1_num_t sec, non, msg;
+    secp256k1_num_init(&sec);
+    secp256k1_num_init(&non);
+    secp256k1_num_init(&msg);
+    secp256k1_num_set_bin(&sec, seckey, 32);
+    secp256k1_num_set_bin(&non, nonce, 32);
+    secp256k1_num_set_bin(&msg, message, messagelen);
+    secp256k1_ecdsa_sig_t sig;
+    secp256k1_ecdsa_sig_init(&sig);
+    int ret = secp256k1_ecdsa_sig_sign(&sig, &sec, &msg, &non, NULL);
+    if (ret) {
+        secp256k1_ecdsa_sig_serialize(signature, signaturelen, &sig);
+    }
+    secp256k1_ecdsa_sig_free(&sig);
+    secp256k1_num_free(&msg);
+    secp256k1_num_free(&non);
+    secp256k1_num_free(&sec);
+    return ret;
+}
+
+int secp256k1_ecdsa_sign_compact(const unsigned char *message, int messagelen, unsigned char *sig64, const unsigned char *seckey, const unsigned char *nonce, int *recid) {
+    secp256k1_num_t sec, non, msg;
+    secp256k1_num_init(&sec);
+    secp256k1_num_init(&non);
+    secp256k1_num_init(&msg);
+    secp256k1_num_set_bin(&sec, seckey, 32);
+    secp256k1_num_set_bin(&non, nonce, 32);
+    secp256k1_num_set_bin(&msg, message, messagelen);
+    secp256k1_ecdsa_sig_t sig;
+    secp256k1_ecdsa_sig_init(&sig);
+    int ret = secp256k1_ecdsa_sig_sign(&sig, &sec, &msg, &non, recid);
+    if (ret) {
+        secp256k1_num_get_bin(sig64, 32, &sig.r);
+        secp256k1_num_get_bin(sig64 + 32, 32, &sig.s);
+    }
+    secp256k1_ecdsa_sig_free(&sig);
+    secp256k1_num_free(&msg);
+    secp256k1_num_free(&non);
+    secp256k1_num_free(&sec);
+    return ret;
+}
+
+int secp256k1_ecdsa_recover_compact(const unsigned char *msg, int msglen, const unsigned char *sig64, unsigned char *pubkey, int *pubkeylen, int compressed, int recid) {
+    int ret = 0;
+    secp256k1_num_t m; 
+    secp256k1_num_init(&m);
+    secp256k1_ecdsa_sig_t sig;
+    secp256k1_ecdsa_sig_init(&sig);
+    secp256k1_num_set_bin(&sig.r, sig64, 32);
+    secp256k1_num_set_bin(&sig.s, sig64 + 32, 32);
+    secp256k1_num_set_bin(&m, msg, msglen);
+
+    secp256k1_ge_t q;
+    if (secp256k1_ecdsa_sig_recover(&sig, &q, &m, recid)) {
+        secp256k1_ecdsa_pubkey_serialize(&q, pubkey, pubkeylen, compressed);
+        ret = 1;
+    }
+    secp256k1_ecdsa_sig_free(&sig);
+    secp256k1_num_free(&m);
+    return ret;
+}
+
+int secp256k1_ecdsa_seckey_verify(const unsigned char *seckey) {
+    secp256k1_num_t sec;
+    secp256k1_num_init(&sec);
+    secp256k1_num_set_bin(&sec, seckey, 32);
+    int ret = !secp256k1_num_is_zero(&sec) &&
+              (secp256k1_num_cmp(&sec, &secp256k1_ge_consts->order) < 0);
+    secp256k1_num_free(&sec);
+    return ret;
+}
+
+int secp256k1_ecdsa_pubkey_verify(const unsigned char *pubkey, int pubkeylen) {
+    secp256k1_ge_t q;
+    return secp256k1_ecdsa_pubkey_parse(&q, pubkey, pubkeylen);
+}
+
+int secp256k1_ecdsa_pubkey_create(unsigned char *pubkey, int *pubkeylen, const unsigned char *seckey, int compressed) {
+    secp256k1_num_t sec;
+    secp256k1_num_init(&sec);
+    secp256k1_num_set_bin(&sec, seckey, 32);
+    secp256k1_gej_t pj;
+    secp256k1_ecmult_gen(&pj, &sec);
+    secp256k1_ge_t p;
+    secp256k1_ge_set_gej(&p, &pj);
+    secp256k1_ecdsa_pubkey_serialize(&p, pubkey, pubkeylen, compressed);
+    return 1;
+}
+
+int secp256k1_ecdsa_pubkey_decompress(unsigned char *pubkey, int *pubkeylen) {
+    secp256k1_ge_t p;
+    if (!secp256k1_ecdsa_pubkey_parse(&p, pubkey, *pubkeylen))
+        return 0;
+    secp256k1_ecdsa_pubkey_serialize(&p, pubkey, pubkeylen, 0);
+    return 1;
+}
+
+int secp256k1_ecdsa_privkey_tweak_add(unsigned char *seckey, const unsigned char *tweak) {
+    int ret = 1;
+    secp256k1_num_t term;
+    secp256k1_num_init(&term);
+    secp256k1_num_set_bin(&term, tweak, 32);
+    if (secp256k1_num_cmp(&term, &secp256k1_ge_consts->order) >= 0)
+        ret = 0;
+    secp256k1_num_t sec;
+    secp256k1_num_init(&sec);
+    if (ret) {
+        secp256k1_num_set_bin(&sec, seckey, 32);
+        secp256k1_num_add(&sec, &sec, &term);
+        secp256k1_num_mod(&sec, &secp256k1_ge_consts->order);
+        if (secp256k1_num_is_zero(&sec))
+            ret = 0;
+    }
+    if (ret)
+        secp256k1_num_get_bin(seckey, 32, &sec);
+    secp256k1_num_free(&sec);
+    secp256k1_num_free(&term);
+    return ret;
+}
+
+int secp256k1_ecdsa_pubkey_tweak_add(unsigned char *pubkey, int pubkeylen, const unsigned char *tweak) {
+    int ret = 1;
+    secp256k1_num_t term;
+    secp256k1_num_init(&term);
+    secp256k1_num_set_bin(&term, tweak, 32);
+    if (secp256k1_num_cmp(&term, &secp256k1_ge_consts->order) >= 0)
+        ret = 0;
+    secp256k1_ge_t p;
+    if (ret) {
+        if (!secp256k1_ecdsa_pubkey_parse(&p, pubkey, pubkeylen))
+            ret = 0;
+    }
+    if (ret) {
+        secp256k1_gej_t pt;
+        secp256k1_ecmult_gen(&pt, &term);
+        secp256k1_gej_add_ge(&pt, &pt, &p);
+        if (secp256k1_gej_is_infinity(&pt))
+            ret = 0;
+        secp256k1_ge_set_gej(&p, &pt);
+        int oldlen = pubkeylen;
+        secp256k1_ecdsa_pubkey_serialize(&p, pubkey, &pubkeylen, oldlen <= 33);
+        assert(pubkeylen == oldlen);
+    }
+    secp256k1_num_free(&term);
+    return ret;
+}
+
+int secp256k1_ecdsa_privkey_tweak_mul(unsigned char *seckey, const unsigned char *tweak) {
+    int ret = 1;
+    secp256k1_num_t factor;
+    secp256k1_num_init(&factor);
+    secp256k1_num_set_bin(&factor, tweak, 32);
+    if (secp256k1_num_is_zero(&factor))
+        ret = 0;
+    if (secp256k1_num_cmp(&factor, &secp256k1_ge_consts->order) >= 0)
+        ret = 0;
+    secp256k1_num_t sec;
+    secp256k1_num_init(&sec);
+    if (ret) {
+        secp256k1_num_set_bin(&sec, seckey, 32);
+        secp256k1_num_mod_mul(&sec, &sec, &factor, &secp256k1_ge_consts->order);
+    }
+    if (ret)
+        secp256k1_num_get_bin(seckey, 32, &sec);
+    secp256k1_num_free(&sec);
+    secp256k1_num_free(&factor);
+    return ret;
+}
+
+int secp256k1_ecdsa_pubkey_tweak_mul(unsigned char *pubkey, int pubkeylen, const unsigned char *tweak) {
+    int ret = 1;
+    secp256k1_num_t factor;
+    secp256k1_num_init(&factor);
+    secp256k1_num_set_bin(&factor, tweak, 32);
+    if (secp256k1_num_is_zero(&factor))
+        ret = 0;
+    if (secp256k1_num_cmp(&factor, &secp256k1_ge_consts->order) >= 0)
+        ret = 0;
+    secp256k1_ge_t p;
+    if (ret) {
+        if (!secp256k1_ecdsa_pubkey_parse(&p, pubkey, pubkeylen))
+            ret = 0;
+    }
+    if (ret) {
+        secp256k1_num_t zero;
+        secp256k1_num_init(&zero);
+        secp256k1_num_set_int(&zero, 0);
+        secp256k1_gej_t pt;
+        secp256k1_gej_set_ge(&pt, &p);
+        secp256k1_ecmult(&pt, &pt, &factor, &zero);
+        secp256k1_num_free(&zero);
+        secp256k1_ge_set_gej(&p, &pt);
+        int oldlen = pubkeylen;
+        secp256k1_ecdsa_pubkey_serialize(&p, pubkey, &pubkeylen, oldlen <= 33);
+        assert(pubkeylen == oldlen);
+    }
+    secp256k1_num_free(&factor);
+    return ret;
+}
+
+int secp256k1_ecdsa_privkey_export(const unsigned char *seckey, unsigned char *privkey, int *privkeylen, int compressed) {
+    secp256k1_num_t key;
+    secp256k1_num_init(&key);
+    secp256k1_num_set_bin(&key, seckey, 32);
+    int ret = secp256k1_ecdsa_privkey_serialize(privkey, privkeylen, &key, compressed);
+    secp256k1_num_free(&key);
+    return ret;
+}
+
+int secp256k1_ecdsa_privkey_import(unsigned char *seckey, const unsigned char *privkey, int privkeylen) {
+    secp256k1_num_t key;
+    secp256k1_num_init(&key);
+    int ret = secp256k1_ecdsa_privkey_parse(&key, privkey, privkeylen);
+    if (ret)
+        secp256k1_num_get_bin(seckey, 32, &key);
+    secp256k1_num_free(&key);
+    return ret;
+}
diff --git a/secp256k1/secp256k1.h b/secp256k1/secp256k1.h
new file mode 100644
index 000000000..fd6d6b1f4
--- /dev/null
+++ b/secp256k1/secp256k1.h
@@ -0,0 +1,121 @@
+#ifndef _SECP256K1_
+#define _SECP256K1_
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/** Initialize the library. This may take some time (10-100 ms).
+ *  You need to call this before calling any other function.
+ *  It cannot run in parallel with any other functions, but once
+ *  secp256k1_start() returns, all other functions are thread-safe.
+ */
+void secp256k1_start(void);
+
+/** Free all memory associated with this library. After this, no
+ *  functions can be called anymore, except secp256k1_start()
+ */
+void secp256k1_stop(void);
+
+/** Verify an ECDSA signature.
+ *  Returns: 1: correct signature
+ *           0: incorrect signature
+ *          -1: invalid public key
+ *          -2: invalid signature
+ */
+int secp256k1_ecdsa_verify(const unsigned char *msg, int msglen,
+                           const unsigned char *sig, int siglen,
+                           const unsigned char *pubkey, int pubkeylen);
+
+/** Create an ECDSA signature.
+ *  Returns: 1: signature created
+ *           0: nonce invalid, try another one
+ *  In:      msg:    the message being signed
+ *           msglen: the length of the message being signed
+ *           seckey: pointer to a 32-byte secret key (assumed to be valid)
+ *           nonce:  pointer to a 32-byte nonce (generated with a cryptographic PRNG)
+ *  Out:     sig:    pointer to a 72-byte array where the signature will be placed.
+ *           siglen: pointer to an int, which will be updated to the signature length (<=72).
+ */
+int secp256k1_ecdsa_sign(const unsigned char *msg, int msglen,
+                         unsigned char *sig, int *siglen,
+                         const unsigned char *seckey,
+                         const unsigned char *nonce);
+
+/** Create a compact ECDSA signature (64 byte + recovery id).
+ *  Returns: 1: signature created
+ *           0: nonce invalid, try another one
+ *  In:      msg:    the message being signed
+ *           msglen: the length of the message being signed
+ *           seckey: pointer to a 32-byte secret key (assumed to be valid)
+ *           nonce:  pointer to a 32-byte nonce (generated with a cryptographic PRNG)
+ *  Out:     sig:    pointer to a 64-byte array where the signature will be placed.
+ *           recid:  pointer to an int, which will be updated to contain the recovery id.
+ */
+int secp256k1_ecdsa_sign_compact(const unsigned char *msg, int msglen,
+                                 unsigned char *sig64,
+                                 const unsigned char *seckey,
+                                 const unsigned char *nonce,
+                                 int *recid);
+
+/** Recover an ECDSA public key from a compact signature.
+ *  Returns: 1: public key succesfully recovered (which guarantees a correct signature).
+ *           0: otherwise.
+ *  In:      msg:        the message assumed to be signed
+ *           msglen:     the length of the message
+ *           sig64:      signature as 64 byte array
+ *           compressed: whether to recover a compressed or uncompressed pubkey
+ *           recid:      the recovery id (as returned by ecdsa_sign_compact)
+ *  Out:     pubkey:     pointer to a 33 or 65 byte array to put the pubkey.
+ *           pubkeylen:  pointer to an int that will contain the pubkey length.
+ */
+
+int secp256k1_ecdsa_recover_compact(const unsigned char *msg, int msglen,
+                                    const unsigned char *sig64,
+                                    unsigned char *pubkey, int *pubkeylen,
+                                    int compressed, int recid);
+
+/** Verify an ECDSA secret key.
+ *  Returns: 1: secret key is valid
+ *           0: secret key is invalid
+ *  In:      seckey: pointer to a 32-byte secret key
+ */
+int secp256k1_ecdsa_seckey_verify(const unsigned char *seckey);
+
+/** Just validate a public key.
+ *  Returns: 1: valid public key
+ *           0: invalid public key
+ */
+int secp256k1_ecdsa_pubkey_verify(const unsigned char *pubkey, int pubkeylen);
+
+/** Compute the public key for a secret key.
+ *  In:     compressed: whether the computed public key should be compressed
+ *          seckey:     pointer to a 32-byte private key.
+ *  Out:    pubkey:     pointer to a 33-byte (if compressed) or 65-byte (if uncompressed)
+ *                      area to store the public key.
+ *          pubkeylen:  pointer to int that will be updated to contains the pubkey's
+ *                      length.
+ *  Returns: 1: secret was valid, public key stores
+ *           0: secret was invalid, try again.
+ */
+int secp256k1_ecdsa_pubkey_create(unsigned char *pubkey, int *pubkeylen, const unsigned char *seckey, int compressed);
+
+int secp256k1_ecdsa_pubkey_decompress(unsigned char *pubkey, int *pubkeylen);
+
+int secp256k1_ecdsa_privkey_export(const unsigned char *seckey,
+                                   unsigned char *privkey, int *privkeylen,
+                                   int compressed);
+
+int secp256k1_ecdsa_privkey_import(unsigned char *seckey,
+                                   const unsigned char *privkey, int privkeylen);
+
+int secp256k1_ecdsa_privkey_tweak_add(unsigned char *seckey, const unsigned char *tweak);
+int secp256k1_ecdsa_pubkey_tweak_add(unsigned char *pubkey, int pubkeylen, const unsigned char *tweak);
+int secp256k1_ecdsa_privkey_tweak_mul(unsigned char *seckey, const unsigned char *tweak);
+int secp256k1_ecdsa_pubkey_tweak_mul(unsigned char *pubkey, int pubkeylen, const unsigned char *tweak);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif
diff --git a/secp256k1/util.h b/secp256k1/util.h
new file mode 100644
index 000000000..357c7e06b
--- /dev/null
+++ b/secp256k1/util.h
@@ -0,0 +1,19 @@
+// Copyright (c) 2013 Pieter Wuille
+// Distributed under the MIT/X11 software license, see the accompanying
+// file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
+#ifndef _SECP256K1_UTIL_H_
+#define _SECP256K1_UTIL_H_
+
+/** Generate a pseudorandom 32-bit number. */
+static uint32_t secp256k1_rand32(void);
+
+/** Generate a pseudorandom 32-byte array. */
+static void secp256k1_rand256(unsigned char *b32);
+
+/** Generate a pseudorandom 32-byte array with long sequences of zero and one bits. */
+static void secp256k1_rand256_test(unsigned char *b32);
+
+#include "impl/util.h"
+
+#endif
diff --git a/test/CMakeLists.txt b/test/CMakeLists.txt
index 538696594..0a7b494b2 100644
--- a/test/CMakeLists.txt
+++ b/test/CMakeLists.txt
@@ -12,7 +12,6 @@ find_package(Threads REQUIRED)
 target_link_libraries(testeth ethereum)
 target_link_libraries(testeth miniupnpc)
 target_link_libraries(testeth ${CRYPTOPP_LIBRARIES})
-target_link_libraries(testeth secp256k1)
 target_link_libraries(testeth gmp)
 target_link_libraries(testeth boost_system)
 target_link_libraries(testeth boost_filesystem)