diff --git a/bitcoin_script.c b/bitcoin_script.c
index a67b91f28..c496b1994 100644
--- a/bitcoin_script.c
+++ b/bitcoin_script.c
@@ -1,6 +1,7 @@
 #include "bitcoin_script.h"
 #include "bitcoin_address.h"
 #include "pkt.h"
+#include "signature.h"
 #include <openssl/ripemd.h>
 #include <ccan/endian/endian.h>
 #include <ccan/crypto/sha256/sha256.h>
@@ -59,6 +60,25 @@ static void add_push_bytes(u8 **scriptp, const void *mem, size_t len)
 	add(scriptp, mem, len);
 }
 
+/* Bitcoin wants DER encoding. */
+static void add_push_sig(u8 **scriptp, const struct signature *sig)
+{
+	u8 der[2 + 2 + sizeof(sig->r) + 2 + sizeof(sig->s)];
+
+	der[0] = 0x30; /* Type */
+	der[1] = sizeof(der) - 2; /* Total length */
+
+	der[2] = 0x2; /* r value type. */
+	der[3] = sizeof(sig->r); /* r length */
+	memcpy(der+4, sig->r, sizeof(sig->r));
+
+	der[4 + sizeof(sig->r)] = 0x2; /* s value type. */
+	der[4 + sizeof(sig->r) + 1] = sizeof(sig->s); /* s value length. */
+	memcpy(der+4+sizeof(sig->r)+2, sig->s, sizeof(sig->s));
+
+	add_push_bytes(scriptp, der, sizeof(der));
+}
+
 /* FIXME: permute? */
 /* Is a < b? (If equal we don't care) */
 static bool key_less(const BitcoinPubkey *a, const BitcoinPubkey *b)
@@ -140,12 +160,11 @@ u8 *scriptpubkey_pay_to_pubkeyhash(const tal_t *ctx,
 
 u8 *scriptsig_pay_to_pubkeyhash(const tal_t *ctx,
 				const struct bitcoin_address *addr,
-				const u8 *signature,
-				size_t sig_len)
+				const struct signature *sig)
 {
 	u8 *script = tal_arr(ctx, u8, 0);
 
-	add_push_bytes(&script, signature, sig_len);
+	add_push_sig(&script, sig);
 	add_push_bytes(&script, addr, sizeof(*addr));
 
 	return script;
diff --git a/bitcoin_script.h b/bitcoin_script.h
index 62f06852d..f71b745d8 100644
--- a/bitcoin_script.h
+++ b/bitcoin_script.h
@@ -6,6 +6,7 @@
 
 struct bitcoin_address;
 struct bitcoin_compressed_pubkey;
+struct signature;
 
 /* tal_count() gives the length of the script. */
 u8 *bitcoin_redeem_2of2(const tal_t *ctx,
@@ -35,8 +36,7 @@ u8 *scriptpubkey_pay_to_pubkeyhash(const tal_t *ctx,
 /* Create an input script to accept pay to pubkey */
 u8 *scriptsig_pay_to_pubkeyhash(const tal_t *ctx,
 				const struct bitcoin_address *addr,
-				const u8 *signature,
-				size_t sig_len);
+				const struct signature *sig);
 
 /* Is this a normal pay to pubkey hash? */
 bool is_pay_to_pubkey_hash(const ProtobufCBinaryData *script);
diff --git a/lightning.pb-c.c b/lightning.pb-c.c
index 661953124..8b6904cd1 100644
--- a/lightning.pb-c.c
+++ b/lightning.pb-c.c
@@ -50,6 +50,49 @@ void   sha256_hash__free_unpacked
   assert(message->base.descriptor == &sha256_hash__descriptor);
   protobuf_c_message_free_unpacked ((ProtobufCMessage*)message, allocator);
 }
+void   signature__init
+                     (Signature         *message)
+{
+  static Signature init_value = SIGNATURE__INIT;
+  *message = init_value;
+}
+size_t signature__get_packed_size
+                     (const Signature *message)
+{
+  assert(message->base.descriptor == &signature__descriptor);
+  return protobuf_c_message_get_packed_size ((const ProtobufCMessage*)(message));
+}
+size_t signature__pack
+                     (const Signature *message,
+                      uint8_t       *out)
+{
+  assert(message->base.descriptor == &signature__descriptor);
+  return protobuf_c_message_pack ((const ProtobufCMessage*)message, out);
+}
+size_t signature__pack_to_buffer
+                     (const Signature *message,
+                      ProtobufCBuffer *buffer)
+{
+  assert(message->base.descriptor == &signature__descriptor);
+  return protobuf_c_message_pack_to_buffer ((const ProtobufCMessage*)message, buffer);
+}
+Signature *
+       signature__unpack
+                     (ProtobufCAllocator  *allocator,
+                      size_t               len,
+                      const uint8_t       *data)
+{
+  return (Signature *)
+     protobuf_c_message_unpack (&signature__descriptor,
+                                allocator, len, data);
+}
+void   signature__free_unpacked
+                     (Signature *message,
+                      ProtobufCAllocator *allocator)
+{
+  assert(message->base.descriptor == &signature__descriptor);
+  protobuf_c_message_free_unpacked ((ProtobufCMessage*)message, allocator);
+}
 void   bitcoin_input__init
                      (BitcoinInput         *message)
 {
@@ -136,49 +179,6 @@ void   bitcoin_output__free_unpacked
   assert(message->base.descriptor == &bitcoin_output__descriptor);
   protobuf_c_message_free_unpacked ((ProtobufCMessage*)message, allocator);
 }
-void   bitcoin_signature__init
-                     (BitcoinSignature         *message)
-{
-  static BitcoinSignature init_value = BITCOIN_SIGNATURE__INIT;
-  *message = init_value;
-}
-size_t bitcoin_signature__get_packed_size
-                     (const BitcoinSignature *message)
-{
-  assert(message->base.descriptor == &bitcoin_signature__descriptor);
-  return protobuf_c_message_get_packed_size ((const ProtobufCMessage*)(message));
-}
-size_t bitcoin_signature__pack
-                     (const BitcoinSignature *message,
-                      uint8_t       *out)
-{
-  assert(message->base.descriptor == &bitcoin_signature__descriptor);
-  return protobuf_c_message_pack ((const ProtobufCMessage*)message, out);
-}
-size_t bitcoin_signature__pack_to_buffer
-                     (const BitcoinSignature *message,
-                      ProtobufCBuffer *buffer)
-{
-  assert(message->base.descriptor == &bitcoin_signature__descriptor);
-  return protobuf_c_message_pack_to_buffer ((const ProtobufCMessage*)message, buffer);
-}
-BitcoinSignature *
-       bitcoin_signature__unpack
-                     (ProtobufCAllocator  *allocator,
-                      size_t               len,
-                      const uint8_t       *data)
-{
-  return (BitcoinSignature *)
-     protobuf_c_message_unpack (&bitcoin_signature__descriptor,
-                                allocator, len, data);
-}
-void   bitcoin_signature__free_unpacked
-                     (BitcoinSignature *message,
-                      ProtobufCAllocator *allocator)
-{
-  assert(message->base.descriptor == &bitcoin_signature__descriptor);
-  protobuf_c_message_free_unpacked ((ProtobufCMessage*)message, allocator);
-}
 void   bitcoin_pubkey__init
                      (BitcoinPubkey         *message)
 {
@@ -1073,6 +1073,135 @@ const ProtobufCMessageDescriptor sha256_hash__descriptor =
   (ProtobufCMessageInit) sha256_hash__init,
   NULL,NULL,NULL    /* reserved[123] */
 };
+static const ProtobufCFieldDescriptor signature__field_descriptors[8] =
+{
+  {
+    "r1",
+    1,
+    PROTOBUF_C_LABEL_REQUIRED,
+    PROTOBUF_C_TYPE_FIXED64,
+    0,   /* quantifier_offset */
+    offsetof(Signature, r1),
+    NULL,
+    NULL,
+    0,             /* flags */
+    0,NULL,NULL    /* reserved1,reserved2, etc */
+  },
+  {
+    "r2",
+    2,
+    PROTOBUF_C_LABEL_REQUIRED,
+    PROTOBUF_C_TYPE_FIXED64,
+    0,   /* quantifier_offset */
+    offsetof(Signature, r2),
+    NULL,
+    NULL,
+    0,             /* flags */
+    0,NULL,NULL    /* reserved1,reserved2, etc */
+  },
+  {
+    "r3",
+    3,
+    PROTOBUF_C_LABEL_REQUIRED,
+    PROTOBUF_C_TYPE_FIXED64,
+    0,   /* quantifier_offset */
+    offsetof(Signature, r3),
+    NULL,
+    NULL,
+    0,             /* flags */
+    0,NULL,NULL    /* reserved1,reserved2, etc */
+  },
+  {
+    "r4",
+    4,
+    PROTOBUF_C_LABEL_REQUIRED,
+    PROTOBUF_C_TYPE_FIXED64,
+    0,   /* quantifier_offset */
+    offsetof(Signature, r4),
+    NULL,
+    NULL,
+    0,             /* flags */
+    0,NULL,NULL    /* reserved1,reserved2, etc */
+  },
+  {
+    "s1",
+    5,
+    PROTOBUF_C_LABEL_REQUIRED,
+    PROTOBUF_C_TYPE_FIXED64,
+    0,   /* quantifier_offset */
+    offsetof(Signature, s1),
+    NULL,
+    NULL,
+    0,             /* flags */
+    0,NULL,NULL    /* reserved1,reserved2, etc */
+  },
+  {
+    "s2",
+    6,
+    PROTOBUF_C_LABEL_REQUIRED,
+    PROTOBUF_C_TYPE_FIXED64,
+    0,   /* quantifier_offset */
+    offsetof(Signature, s2),
+    NULL,
+    NULL,
+    0,             /* flags */
+    0,NULL,NULL    /* reserved1,reserved2, etc */
+  },
+  {
+    "s3",
+    7,
+    PROTOBUF_C_LABEL_REQUIRED,
+    PROTOBUF_C_TYPE_FIXED64,
+    0,   /* quantifier_offset */
+    offsetof(Signature, s3),
+    NULL,
+    NULL,
+    0,             /* flags */
+    0,NULL,NULL    /* reserved1,reserved2, etc */
+  },
+  {
+    "s4",
+    8,
+    PROTOBUF_C_LABEL_REQUIRED,
+    PROTOBUF_C_TYPE_FIXED64,
+    0,   /* quantifier_offset */
+    offsetof(Signature, s4),
+    NULL,
+    NULL,
+    0,             /* flags */
+    0,NULL,NULL    /* reserved1,reserved2, etc */
+  },
+};
+static const unsigned signature__field_indices_by_name[] = {
+  0,   /* field[0] = r1 */
+  1,   /* field[1] = r2 */
+  2,   /* field[2] = r3 */
+  3,   /* field[3] = r4 */
+  4,   /* field[4] = s1 */
+  5,   /* field[5] = s2 */
+  6,   /* field[6] = s3 */
+  7,   /* field[7] = s4 */
+};
+static const ProtobufCIntRange signature__number_ranges[1 + 1] =
+{
+  { 1, 0 },
+  { 0, 8 }
+};
+const ProtobufCMessageDescriptor signature__descriptor =
+{
+  PROTOBUF_C__MESSAGE_DESCRIPTOR_MAGIC,
+  "signature",
+  "Signature",
+  "Signature",
+  "",
+  sizeof(Signature),
+  8,
+  signature__field_descriptors,
+  signature__field_indices_by_name,
+  1,  signature__number_ranges,
+  (ProtobufCMessageInit) signature__init,
+  NULL,NULL,NULL    /* reserved[123] */
+};
 static const ProtobufCFieldDescriptor bitcoin_input__field_descriptors[4] =
 {
   {
@@ -1201,44 +1330,6 @@ const ProtobufCMessageDescriptor bitcoin_output__descriptor =
   (ProtobufCMessageInit) bitcoin_output__init,
   NULL,NULL,NULL    /* reserved[123] */
 };
-static const ProtobufCFieldDescriptor bitcoin_signature__field_descriptors[1] =
-{
-  {
-    "der_then_sigtype",
-    1,
-    PROTOBUF_C_LABEL_REQUIRED,
-    PROTOBUF_C_TYPE_BYTES,
-    0,   /* quantifier_offset */
-    offsetof(BitcoinSignature, der_then_sigtype),
-    NULL,
-    NULL,
-    0,             /* flags */
-    0,NULL,NULL    /* reserved1,reserved2, etc */
-  },
-};
-static const unsigned bitcoin_signature__field_indices_by_name[] = {
-  0,   /* field[0] = der_then_sigtype */
-};
-static const ProtobufCIntRange bitcoin_signature__number_ranges[1 + 1] =
-{
-  { 1, 0 },
-  { 0, 1 }
-};
-const ProtobufCMessageDescriptor bitcoin_signature__descriptor =
-{
-  PROTOBUF_C__MESSAGE_DESCRIPTOR_MAGIC,
-  "bitcoin_signature",
-  "BitcoinSignature",
-  "BitcoinSignature",
-  "",
-  sizeof(BitcoinSignature),
-  1,
-  bitcoin_signature__field_descriptors,
-  bitcoin_signature__field_indices_by_name,
-  1,  bitcoin_signature__number_ranges,
-  (ProtobufCMessageInit) bitcoin_signature__init,
-  NULL,NULL,NULL    /* reserved[123] */
-};
 static const ProtobufCFieldDescriptor bitcoin_pubkey__field_descriptors[1] =
 {
   {
@@ -1509,7 +1600,7 @@ static const ProtobufCFieldDescriptor open_commit_sig__field_descriptors[1] =
     PROTOBUF_C_TYPE_MESSAGE,
     0,   /* quantifier_offset */
     offsetof(OpenCommitSig, sig),
-    &bitcoin_signature__descriptor,
+    &signature__descriptor,
     NULL,
     0,             /* flags */
     0,NULL,NULL    /* reserved1,reserved2, etc */
@@ -1685,7 +1776,7 @@ static const ProtobufCFieldDescriptor update__field_descriptors[4] =
     PROTOBUF_C_TYPE_MESSAGE,
     0,   /* quantifier_offset */
     offsetof(Update, sig),
-    &bitcoin_signature__descriptor,
+    &signature__descriptor,
     NULL,
     0,             /* flags */
     0,NULL,NULL    /* reserved1,reserved2, etc */
@@ -1697,7 +1788,7 @@ static const ProtobufCFieldDescriptor update__field_descriptors[4] =
     PROTOBUF_C_TYPE_MESSAGE,
     0,   /* quantifier_offset */
     offsetof(Update, old_anchor_sig),
-    &bitcoin_signature__descriptor,
+    &signature__descriptor,
     NULL,
     0,             /* flags */
     0,NULL,NULL    /* reserved1,reserved2, etc */
@@ -1738,7 +1829,7 @@ static const ProtobufCFieldDescriptor update_accept__field_descriptors[3] =
     PROTOBUF_C_TYPE_MESSAGE,
     0,   /* quantifier_offset */
     offsetof(UpdateAccept, sig),
-    &bitcoin_signature__descriptor,
+    &signature__descriptor,
     NULL,
     0,             /* flags */
     0,NULL,NULL    /* reserved1,reserved2, etc */
@@ -1750,7 +1841,7 @@ static const ProtobufCFieldDescriptor update_accept__field_descriptors[3] =
     PROTOBUF_C_TYPE_MESSAGE,
     0,   /* quantifier_offset */
     offsetof(UpdateAccept, old_anchor_sig),
-    &bitcoin_signature__descriptor,
+    &signature__descriptor,
     NULL,
     0,             /* flags */
     0,NULL,NULL    /* reserved1,reserved2, etc */
@@ -1916,7 +2007,7 @@ static const ProtobufCFieldDescriptor new_anchor_commit_sig__field_descriptors[1
     PROTOBUF_C_TYPE_MESSAGE,
     0,   /* quantifier_offset */
     offsetof(NewAnchorCommitSig, sig),
-    &bitcoin_signature__descriptor,
+    &signature__descriptor,
     NULL,
     0,             /* flags */
     0,NULL,NULL    /* reserved1,reserved2, etc */
@@ -2030,7 +2121,7 @@ static const ProtobufCFieldDescriptor close_channel__field_descriptors[1] =
     PROTOBUF_C_TYPE_MESSAGE,
     0,   /* quantifier_offset */
     offsetof(CloseChannel, sig),
-    &bitcoin_signature__descriptor,
+    &signature__descriptor,
     NULL,
     0,             /* flags */
     0,NULL,NULL    /* reserved1,reserved2, etc */
@@ -2068,7 +2159,7 @@ static const ProtobufCFieldDescriptor close_channel_complete__field_descriptors[
     PROTOBUF_C_TYPE_MESSAGE,
     0,   /* quantifier_offset */
     offsetof(CloseChannelComplete, sig),
-    &bitcoin_signature__descriptor,
+    &signature__descriptor,
     NULL,
     0,             /* flags */
     0,NULL,NULL    /* reserved1,reserved2, etc */
diff --git a/lightning.pb-c.h b/lightning.pb-c.h
index 554918482..1ab668498 100644
--- a/lightning.pb-c.h
+++ b/lightning.pb-c.h
@@ -16,9 +16,9 @@ PROTOBUF_C__BEGIN_DECLS
 
 
 typedef struct _Sha256Hash Sha256Hash;
+typedef struct _Signature Signature;
 typedef struct _BitcoinInput BitcoinInput;
 typedef struct _BitcoinOutput BitcoinOutput;
-typedef struct _BitcoinSignature BitcoinSignature;
 typedef struct _BitcoinPubkey BitcoinPubkey;
 typedef struct _Anchor Anchor;
 typedef struct _OpenChannel OpenChannel;
@@ -46,7 +46,7 @@ typedef struct _Pkt Pkt;
 /* --- messages --- */
 
 /*
- * Protobufs don't have fixed-length fields, so this is a hack.
+ * Protobufs don't have fixed-length fields, so these are a hack.
  */
 struct  _Sha256Hash
 {
@@ -61,6 +61,23 @@ struct  _Sha256Hash
     , 0, 0, 0, 0 }
 
 
+struct  _Signature
+{
+  ProtobufCMessage base;
+  uint64_t r1;
+  uint64_t r2;
+  uint64_t r3;
+  uint64_t r4;
+  uint64_t s1;
+  uint64_t s2;
+  uint64_t s3;
+  uint64_t s4;
+};
+#define SIGNATURE__INIT \
+ { PROTOBUF_C_MESSAGE_INIT (&signature__descriptor) \
+    , 0, 0, 0, 0, 0, 0, 0, 0 }
+
+
 /*
  * Identifies consumption of a bitcoin output.
  */
@@ -103,19 +120,6 @@ struct  _BitcoinOutput
     , 0, {0,NULL} }
 
 
-/*
- * A signature to use for a transaction; DER encoded with sigtype at the end.
- */
-struct  _BitcoinSignature
-{
-  ProtobufCMessage base;
-  ProtobufCBinaryData der_then_sigtype;
-};
-#define BITCOIN_SIGNATURE__INIT \
- { PROTOBUF_C_MESSAGE_INIT (&bitcoin_signature__descriptor) \
-    , {0,NULL} }
-
-
 /*
  * Pubkey for commitment transaction input.
  */
@@ -215,7 +219,7 @@ struct  _OpenChannel
 struct  _OpenCommitSig
 {
   ProtobufCMessage base;
-  BitcoinSignature *sig;
+  Signature *sig;
 };
 #define OPEN_COMMIT_SIG__INIT \
  { PROTOBUF_C_MESSAGE_INIT (&open_commit_sig__descriptor) \
@@ -291,14 +295,14 @@ struct  _Update
   /*
    * Signature for new commitment tx.
    */
-  BitcoinSignature *sig;
+  Signature *sig;
   /*
    * Signature for old anchor (if any)
    */
   /*
    * FIXME: optional HTLC ops.
    */
-  BitcoinSignature *old_anchor_sig;
+  Signature *old_anchor_sig;
 };
 #define UPDATE__INIT \
  { PROTOBUF_C_MESSAGE_INIT (&update__descriptor) \
@@ -314,11 +318,11 @@ struct  _UpdateAccept
   /*
    * Signature for new commitment tx.
    */
-  BitcoinSignature *sig;
+  Signature *sig;
   /*
    * Signature for old anchor (if any)
    */
-  BitcoinSignature *old_anchor_sig;
+  Signature *old_anchor_sig;
   /*
    * Hash preimage which revokes old commitment tx.
    */
@@ -380,7 +384,7 @@ struct  _NewAnchorAck
 struct  _NewAnchorCommitSig
 {
   ProtobufCMessage base;
-  BitcoinSignature *sig;
+  Signature *sig;
 };
 #define NEW_ANCHOR_COMMIT_SIG__INIT \
  { PROTOBUF_C_MESSAGE_INIT (&new_anchor_commit_sig__descriptor) \
@@ -425,7 +429,7 @@ struct  _CloseChannel
    * This is our signature a new transaction which spends my current
    * commitment tx output 0 (which is 2/2) to script_to_me.
    */
-  BitcoinSignature *sig;
+  Signature *sig;
 };
 #define CLOSE_CHANNEL__INIT \
  { PROTOBUF_C_MESSAGE_INIT (&close_channel__descriptor) \
@@ -442,7 +446,7 @@ struct  _CloseChannelComplete
    * This is our signature a new transaction which spends your current
    * commitment tx output 0 (which is 2/2) to your script_to_me.
    */
-  BitcoinSignature *sig;
+  Signature *sig;
 };
 #define CLOSE_CHANNEL_COMPLETE__INIT \
  { PROTOBUF_C_MESSAGE_INIT (&close_channel_complete__descriptor) \
@@ -545,6 +549,25 @@ Sha256Hash *
 void   sha256_hash__free_unpacked
                      (Sha256Hash *message,
                       ProtobufCAllocator *allocator);
+/* Signature methods */
+void   signature__init
+                     (Signature         *message);
+size_t signature__get_packed_size
+                     (const Signature   *message);
+size_t signature__pack
+                     (const Signature   *message,
+                      uint8_t             *out);
+size_t signature__pack_to_buffer
+                     (const Signature   *message,
+                      ProtobufCBuffer     *buffer);
+Signature *
+       signature__unpack
+                     (ProtobufCAllocator  *allocator,
+                      size_t               len,
+                      const uint8_t       *data);
+void   signature__free_unpacked
+                     (Signature *message,
+                      ProtobufCAllocator *allocator);
 /* BitcoinInput methods */
 void   bitcoin_input__init
                      (BitcoinInput         *message);
@@ -583,25 +606,6 @@ BitcoinOutput *
 void   bitcoin_output__free_unpacked
                      (BitcoinOutput *message,
                       ProtobufCAllocator *allocator);
-/* BitcoinSignature methods */
-void   bitcoin_signature__init
-                     (BitcoinSignature         *message);
-size_t bitcoin_signature__get_packed_size
-                     (const BitcoinSignature   *message);
-size_t bitcoin_signature__pack
-                     (const BitcoinSignature   *message,
-                      uint8_t             *out);
-size_t bitcoin_signature__pack_to_buffer
-                     (const BitcoinSignature   *message,
-                      ProtobufCBuffer     *buffer);
-BitcoinSignature *
-       bitcoin_signature__unpack
-                     (ProtobufCAllocator  *allocator,
-                      size_t               len,
-                      const uint8_t       *data);
-void   bitcoin_signature__free_unpacked
-                     (BitcoinSignature *message,
-                      ProtobufCAllocator *allocator);
 /* BitcoinPubkey methods */
 void   bitcoin_pubkey__init
                      (BitcoinPubkey         *message);
@@ -968,15 +972,15 @@ void   pkt__free_unpacked
 typedef void (*Sha256Hash_Closure)
                  (const Sha256Hash *message,
                   void *closure_data);
+typedef void (*Signature_Closure)
+                 (const Signature *message,
+                  void *closure_data);
 typedef void (*BitcoinInput_Closure)
                  (const BitcoinInput *message,
                   void *closure_data);
 typedef void (*BitcoinOutput_Closure)
                  (const BitcoinOutput *message,
                   void *closure_data);
-typedef void (*BitcoinSignature_Closure)
-                 (const BitcoinSignature *message,
-                  void *closure_data);
 typedef void (*BitcoinPubkey_Closure)
                  (const BitcoinPubkey *message,
                   void *closure_data);
@@ -1041,9 +1045,9 @@ typedef void (*Pkt_Closure)
 /* --- descriptors --- */
 
 extern const ProtobufCMessageDescriptor sha256_hash__descriptor;
+extern const ProtobufCMessageDescriptor signature__descriptor;
 extern const ProtobufCMessageDescriptor bitcoin_input__descriptor;
 extern const ProtobufCMessageDescriptor bitcoin_output__descriptor;
-extern const ProtobufCMessageDescriptor bitcoin_signature__descriptor;
 extern const ProtobufCMessageDescriptor bitcoin_pubkey__descriptor;
 extern const ProtobufCMessageDescriptor anchor__descriptor;
 extern const ProtobufCMessageDescriptor open_channel__descriptor;
diff --git a/lightning.proto b/lightning.proto
index 4381d8ff9..29efd4312 100644
--- a/lightning.proto
+++ b/lightning.proto
@@ -5,7 +5,7 @@
 // Helper Types
 //
 
-// Protobufs don't have fixed-length fields, so this is a hack.
+// Protobufs don't have fixed-length fields, so these are a hack.
 message sha256_hash {
   required fixed64 a = 1;
   required fixed64 b = 2;
@@ -13,6 +13,17 @@ message sha256_hash {
   required fixed64 d = 4;
 }
 
+message signature {
+  required fixed64 r1 = 1;
+  required fixed64 r2 = 2;
+  required fixed64 r3 = 3;
+  required fixed64 r4 = 4;
+  required fixed64 s1 = 5;
+  required fixed64 s2 = 6;
+  required fixed64 s3 = 7;
+  required fixed64 s4 = 8;
+}
+
 // Identifies consumption of a bitcoin output.
 message bitcoin_input {
   // This is the transaction ID.
@@ -31,11 +42,6 @@ message bitcoin_output {
   required bytes script = 2;
 }
 
-// A signature to use for a transaction; DER encoded with sigtype at the end.
-message bitcoin_signature {
-  required bytes der_then_sigtype = 1;
-};
-
 // Pubkey for commitment transaction input.
 message bitcoin_pubkey {
   // Either 65 or 33 bytes.
@@ -82,7 +88,7 @@ message open_channel {
 
 // Supply signature for commitment tx
 message open_commit_sig {
-  required bitcoin_signature sig = 1;
+  required signature sig = 1;
 }
 
 // Supply ScriptSig for each anchor tx inputs.
@@ -116,18 +122,18 @@ message update {
   // Change in current payment to-me (implies reverse to-you).
   required sint64 delta = 2;
   // Signature for new commitment tx.
-  required bitcoin_signature sig = 3;
+  required signature sig = 3;
   // Signature for old anchor (if any)
-  optional bitcoin_signature old_anchor_sig = 4;
+  optional signature old_anchor_sig = 4;
   // FIXME: optional HTLC ops.
 }
 
 // OK, I accept that update.
 message update_accept {
   // Signature for new commitment tx.
-  required bitcoin_signature sig = 1;
+  required signature sig = 1;
   // Signature for old anchor (if any)
-  optional bitcoin_signature old_anchor_sig = 2;
+  optional signature old_anchor_sig = 2;
   // Hash preimage which revokes old commitment tx.
   required sha256_hash revocation_preimage = 3;
 }
@@ -151,7 +157,7 @@ message new_anchor_ack {
 
 // Now we both send signatures for new commit sig.
 message new_anchor_commit_sig {
-  required bitcoin_signature sig = 1;
+  required signature sig = 1;
 }
 
 // Here are the script sigs for the new anchor's new inputs.
@@ -169,14 +175,14 @@ message new_anchor_complete {
 message close_channel {
   // This is our signature a new transaction which spends my current
   // commitment tx output 0 (which is 2/2) to script_to_me.
-  required bitcoin_signature sig = 1;
+  required signature sig = 1;
 }
 
 // OK, here's my sig so you can broadcast it too.
 message close_channel_complete {
   // This is our signature a new transaction which spends your current
   // commitment tx output 0 (which is 2/2) to your script_to_me.
-  required bitcoin_signature sig = 1;
+  required signature sig = 1;
 }
 
 // This means we're going to hang up; it's to help diagnose only! 
diff --git a/open-anchor-sig.c b/open-anchor-sig.c
index 58665a2eb..c55008925 100644
--- a/open-anchor-sig.c
+++ b/open-anchor-sig.c
@@ -25,7 +25,7 @@ static u8 *tx_scriptsig(const tal_t *ctx,
 			EC_KEY *privkey,
 			const struct bitcoin_compressed_pubkey *pubkey)
 {
-	u8 *sig;
+	struct signature *sig;
 	struct bitcoin_address addr;
 
 	sig = sign_tx_input(ctx, tx, i,
@@ -37,7 +37,7 @@ static u8 *tx_scriptsig(const tal_t *ctx,
 	if (!is_pay_to_pubkey_hash(&input->subscript))
 		errx(1, "FIXME: Don't know how to handle input");
 	bitcoin_address(pubkey, &addr);
-	return scriptsig_pay_to_pubkeyhash(ctx, &addr, sig, tal_count(sig));
+	return scriptsig_pay_to_pubkeyhash(ctx, &addr, sig);
 }
 	
 int main(int argc, char *argv[])
diff --git a/open-commit-sig.c b/open-commit-sig.c
index 5b6c50fb9..7349e6d47 100644
--- a/open-commit-sig.c
+++ b/open-commit-sig.c
@@ -27,7 +27,7 @@ int main(int argc, char *argv[])
 	struct bitcoin_tx *anchor, *commit;
 	struct sha256_double txid;
 	struct pkt *pkt;
-	u8 *sig;
+	struct signature *sig;
 	size_t *inmap, *outmap;
 	EC_KEY *privkey;
 	bool testnet;
@@ -76,7 +76,7 @@ int main(int argc, char *argv[])
 	sig = sign_tx_input(ctx, commit, 0, anchor->output[outmap[0]].script,
 			    anchor->output[outmap[0]].script_length, privkey);
 
-	pkt = open_commit_sig_pkt(ctx, sig, tal_count(sig));
+	pkt = open_commit_sig_pkt(ctx, sig);
 	if (!write_all(STDOUT_FILENO, pkt,
 		       sizeof(pkt->len) + le32_to_cpu(pkt->len)))
 		err(1, "Writing out packet");
diff --git a/pkt.c b/pkt.c
index 98f6df87c..8c90dabd1 100644
--- a/pkt.c
+++ b/pkt.c
@@ -1,10 +1,10 @@
 #include <ccan/crypto/sha256/sha256.h>
 #include <ccan/tal/grab_file/grab_file.h>
 #include <ccan/err/err.h>
-#include <ccan/cast/cast.h>
 #include "pkt.h"
 #include "bitcoin_tx.h"
 #include "bitcoin_address.h"
+#include "signature.h"
 
 #include <stdio.h>
 static struct pkt *to_pkt(const tal_t *ctx, Pkt__PktCase type, void *msg)
@@ -47,6 +47,37 @@ void proto_to_sha256(const Sha256Hash *pb, struct sha256 *hash)
 	memcpy(hash->u.u8 + 24, &pb->d, 8);
 }
 
+Signature *signature_to_proto(const tal_t *ctx, const struct signature *sig)
+{
+	Signature *pb = tal(ctx, Signature);
+	signature__init(pb);
+
+	/* Kill me now... */
+	memcpy(&pb->r1, sig->r, 8);
+	memcpy(&pb->r2, sig->r + 8, 8);
+	memcpy(&pb->r3, sig->r + 16, 8);
+	memcpy(&pb->r4, sig->r + 24, 8);
+	memcpy(&pb->s1, sig->s, 8);
+	memcpy(&pb->s2, sig->s + 8, 8);
+	memcpy(&pb->s3, sig->s + 16, 8);
+	memcpy(&pb->s4, sig->s + 24, 8);
+
+	return pb;
+}
+
+void proto_to_signature(const Signature *pb, struct signature *sig)
+{
+	/* Kill me again. */
+	memcpy(sig->r, &pb->r1, 8);
+	memcpy(sig->r + 8, &pb->r2, 8);
+	memcpy(sig->r + 16, &pb->r3, 8);
+	memcpy(sig->r + 24, &pb->r4, 8);
+	memcpy(sig->s, &pb->s1, 8);
+	memcpy(sig->s + 8, &pb->s2, 8);
+	memcpy(sig->s + 16, &pb->s3, 8);
+	memcpy(sig->s + 24, &pb->s4, 8);
+}
+
 BitcoinPubkey *pubkey_to_proto(const tal_t *ctx,
 			       const struct bitcoin_compressed_pubkey *key)
 {
@@ -142,14 +173,10 @@ struct pkt *leak_anchor_sigs_and_pretend_we_didnt_pkt(const tal_t *ctx,
 	return to_pkt(ctx, PKT__PKT_OMG_FAIL, &omg_fail);
 }
 
-struct pkt *open_commit_sig_pkt(const tal_t *ctx, const u8 *sig, size_t siglen)
+struct pkt *open_commit_sig_pkt(const tal_t *ctx, const struct signature *sig)
 {
 	OpenCommitSig o = OPEN_COMMIT_SIG__INIT;
-	BitcoinSignature s = BITCOIN_SIGNATURE__INIT;
-
-	o.sig = &s;
-	s.der_then_sigtype.len = siglen;
-	s.der_then_sigtype.data = cast_const(u8 *, sig);
 
+	o.sig = signature_to_proto(ctx, sig);
 	return to_pkt(ctx, PKT__PKT_OPEN_COMMIT_SIG, &o);
 }
diff --git a/pkt.h b/pkt.h
index 6645b4701..295e32aca 100644
--- a/pkt.h
+++ b/pkt.h
@@ -21,6 +21,7 @@ Pkt *pkt_from_file(const char *filename, Pkt__PktCase expect);
 
 struct sha256;
 struct bitcoin_compressed_pubkey;
+struct signature;
 
 /**
  * openchannel_pkt - create an openchannel message
@@ -61,15 +62,17 @@ struct pkt *leak_anchor_sigs_and_pretend_we_didnt_pkt(const tal_t *ctx,
 /**
  * open_commit_sig_pkt - create an open_commit_sig message
  * @ctx: tal context to allocate off.
- * @sig: the der-encoded signature for the commit transaction input.
- * @siglen: the length of @sig.
+ * @sig: the signature for the commit transaction input.
  */
-struct pkt *open_commit_sig_pkt(const tal_t *ctx, const u8 *sig, size_t siglen);
+struct pkt *open_commit_sig_pkt(const tal_t *ctx, const struct signature *sig);
 
 /* Useful helper for allocating & populating a protobuf Sha256Hash */
 Sha256Hash *sha256_to_proto(const tal_t *ctx, const struct sha256 *hash);
 void proto_to_sha256(const Sha256Hash *pb, struct sha256 *hash);
 
+Signature *signature_to_proto(const tal_t *ctx, const struct signature *sig);
+void proto_to_signature(const Signature *pb, struct signature *sig);
+
 BitcoinPubkey *pubkey_to_proto(const tal_t *ctx,
 			       const struct bitcoin_compressed_pubkey *key);
 #endif /* LIGHTNING_PKT_H */
diff --git a/signature.c b/signature.c
index 9b585c9d3..28c6ae4a8 100644
--- a/signature.c
+++ b/signature.c
@@ -6,12 +6,12 @@
 #include <assert.h>
 #include <ccan/cast/cast.h>
 
-u8 *sign_hash(const tal_t *ctx, EC_KEY *private_key,
-	      const struct sha256_double *h)
+struct signature *sign_hash(const tal_t *ctx, EC_KEY *private_key,
+			    const struct sha256_double *h)
 {
 	ECDSA_SIG *sig;
 	int len;
-	unsigned char *der, *ret;
+	struct signature *s;
 	
 	sig = ECDSA_do_sign(h->sha.u.u8, sizeof(*h), private_key);
 	if (!sig)
@@ -33,21 +33,24 @@ u8 *sign_hash(const tal_t *ctx, EC_KEY *private_key,
 		assert(!BN_is_odd(sig->s));
         }
 
-	/* This tells it to allocate for us. */
-	der = NULL;
-	len = i2d_ECDSA_SIG(sig, &der);
-	ECDSA_SIG_free(sig);
+	s = talz(ctx, struct signature);
 
-	if (len <= 0)
-		return NULL;
+	/* Pack r and s into signature, 32 bytes each. */
+	len = BN_num_bytes(sig->r);
+	assert(len <= sizeof(s->r));
+	BN_bn2bin(sig->r, s->r + sizeof(s->r) - len);
+	len = BN_num_bytes(sig->s);
+	assert(len <= sizeof(s->s));
+	BN_bn2bin(sig->s, s->s + sizeof(s->s) - len);
 
-	ret = tal_dup_arr(ctx, u8, der, len, 0);
-	OPENSSL_free(der);
-	return ret;
+	ECDSA_SIG_free(sig);
+	return s;
 }
 
-u8 *sign_tx_input(const tal_t *ctx, struct bitcoin_tx *tx, unsigned int in,
-		  const u8 *subscript, size_t subscript_len, EC_KEY *privkey)
+struct signature *sign_tx_input(const tal_t *ctx, struct bitcoin_tx *tx,
+				unsigned int in,
+				const u8 *subscript, size_t subscript_len,
+				EC_KEY *privkey)
 {
 	struct sha256_double hash;
 	struct sha256_ctx shactx;
diff --git a/signature.h b/signature.h
index d08941e82..55989d474 100644
--- a/signature.h
+++ b/signature.h
@@ -11,14 +11,22 @@ enum sighash_type {
     SIGHASH_ANYONECANPAY = 0x80
 };
 
+/* ECDSA of double SHA256. */
+struct signature {
+	u8 r[32];
+	u8 s[32];
+};
+
 struct sha256_double;
 struct bitcoin_tx;
 
-u8 *sign_hash(const tal_t *ctx, EC_KEY *private_key,
-	      const struct sha256_double *h);
+struct signature *sign_hash(const tal_t *ctx, EC_KEY *private_key,
+			    const struct sha256_double *h);
 
 /* All tx input scripts must be set to 0 len. */
-u8 *sign_tx_input(const tal_t *ctx, struct bitcoin_tx *tx, unsigned int in,
-		  const u8 *subscript, size_t subscript_len, EC_KEY *privkey);
+struct signature *sign_tx_input(const tal_t *ctx,
+				struct bitcoin_tx *tx, unsigned int in,
+				const u8 *subscript, size_t subscript_len,
+				EC_KEY *privkey);
 
 #endif /* LIGHTNING_SIGNATURE_H */