diff --git a/lib/crypto/bn.js b/lib/crypto/bn.js
index 60874d9..e084f61 100644
--- a/lib/crypto/bn.js
+++ b/lib/crypto/bn.js
@@ -1,23 +1,30 @@
+/**
+ * @file ecdsa.js
+ * @license MIT
+ *
+ * Copyright (c) 2014 reddit, Inc.
+ * Copyright (c) 2014 Ryan X. Charles
+ * Copyright (c) 2014 BitPay, Inc.
+ */
 'use strict';
 
 var _BN = require('bn.js');
 
-var BN = function BN_extended(n) {
-  if (!(this instanceof BN_extended)) {
-    return new BN(n);
+var BN = function BN(n, base) {
+  if (!(this instanceof BN)) {
+    return new BN(n, base);
   }
-  arguments[0] = n;
-  return _BN.apply(this, arguments);
+  _BN.apply(this, arguments);
 };
 
-module.exports = BN;
-
 BN.prototype = _BN.prototype;
 
-var reversebuf = function(buf, nbuf) {
+var reversebuf = function(buf) {
+  var buf2 = new Buffer(buf.length);
   for (var i = 0; i < buf.length; i++) {
-    nbuf[i] = buf[buf.length-1-i];
+    buf2[i] = buf[buf.length-1-i];
   }
+  return buf2;
 };
 
 BN.prototype.toJSON = function() {
@@ -30,6 +37,16 @@ BN.prototype.fromJSON = function(str) {
   return this;
 };
 
+BN.prototype.fromNumber = function(n) {
+  var bn = BN(n);
+  bn.copy(this);
+  return this;
+};
+
+BN.prototype.toNumber = function() {
+  return parseInt(this['toString'](10), 10);
+};
+
 BN.prototype.fromString = function(str) {
   var bn = BN(str);
   bn.copy(this);
@@ -38,9 +55,7 @@ BN.prototype.fromString = function(str) {
 
 BN.fromBuffer = function(buf, opts) {
   if (typeof opts !== 'undefined' && opts.endian === 'little') {
-    var nbuf = new Buffer(buf.length);
-    reversebuf(buf, nbuf);
-    buf = nbuf;
+    buf = reversebuf(buf);
   }
   var hex = buf.toString('hex');
   var bn = new BN(hex, 16);
@@ -70,7 +85,6 @@ BN.prototype.toBuffer = function(opts) {
 
     else if (natlen < opts.size) {
       var rbuf = new Buffer(opts.size);
-      //rbuf.fill(0);
       for (var i = 0; i < buf.length; i++)
         rbuf[rbuf.length-1-i] = buf[buf.length-1-i];
       for (var i = 0; i < opts.size - natlen; i++)
@@ -84,31 +98,116 @@ BN.prototype.toBuffer = function(opts) {
   }
 
   if (typeof opts !== 'undefined' && opts.endian === 'little') {
-    var nbuf = new Buffer(buf.length);
-    reversebuf(buf, nbuf);
-    buf = nbuf;
+    buf = reversebuf(buf);
   }
 
   return buf;
 };
 
+// signed magnitude buffer
+// most significant bit represents sign (0 = positive, -1 = negative)
+BN.prototype.fromSM = function(buf, opts) {
+  if (buf.length === 0)
+    this.fromBuffer(new Buffer([0]));
+
+  var endian = 'big';
+  if (opts)
+    endian = opts.endian;
+
+  if (endian == 'little')
+    buf = reversebuf(buf);
+
+  if (buf[0] & 0x80) {
+    buf[0] = buf[0] & 0x7f;
+    this.fromBuffer(buf);
+    this.neg().copy(this);
+  } else {
+    this.fromBuffer(buf);
+  }
+  return this;
+};
+
+BN.prototype.toSM = function(opts) {
+  var endian = 'big';
+  if (opts)
+    endian = opts.endian;
+
+  var buf;
+  if (this.cmp(0) == -1) {
+    buf = this.neg().toBuffer();
+    if (buf[0] & 0x80)
+      buf = Buffer.concat([new Buffer([0x80]), buf]);
+    else
+      buf[0] = buf[0] | 0x80;
+  } else {
+    buf = this.toBuffer();
+    if (buf[0] & 0x80)
+      buf = Buffer.concat([new Buffer([0x00]), buf]);
+  }
+
+  if (buf.length === 1 & buf[0] === 0)
+    buf = new Buffer([]);
+
+  if (endian == 'little')
+    buf = reversebuf(buf);
+
+  return buf;
+};
+
+// This is analogous to the constructor for CScriptNum in bitcoind. Many ops in
+// bitcoind's script interpreter use CScriptNum, which is not really a proper
+// bignum. Instead, an error is thrown if trying to input a number bigger than
+// 4 bytes. We copy that behavior here.
+BN.prototype.fromCScriptNumBuffer = function(buf, fRequireMinimal) {
+  var nMaxNumSize = 4;
+  if (buf.length > nMaxNumSize)
+    throw new Error('script number overflow');
+  if (fRequireMinimal && buf.length > 0) {
+    // Check that the number is encoded with the minimum possible
+    // number of bytes.
+    //
+    // If the most-significant-byte - excluding the sign bit - is zero
+    // then we're not minimal. Note how this test also rejects the
+    // negative-zero encoding, 0x80.
+    if ((buf[buf.length - 1] & 0x7f) === 0) {
+      // One exception: if there's more than one byte and the most
+      // significant bit of the second-most-significant-byte is set
+      // it would conflict with the sign bit. An example of this case
+      // is +-255, which encode to 0xff00 and 0xff80 respectively.
+      // (big-endian).
+      if (buf.length <= 1 || (buf[buf.length - 2] & 0x80) === 0) {
+        throw new Error("non-minimally encoded script number");
+      }
+    }
+  }
+  return this.fromSM(buf, {endian: 'little'});
+};
+
+// The corollary to the above, with the notable exception that we do not throw
+// an error if the output is larger than four bytes. (Which can happen if
+// performing a numerical operation that results in an overflow to more than 4
+// bytes).
+BN.prototype.toCScriptNumBuffer = function(buf) {
+  return this.toSM({endian: 'little'});
+};
+
 function decorate(name) {
-  BN.prototype['_' + name] = _BN.prototype[name];
+  BN.prototype['_' + name] = BN.prototype[name];
   var f = function(b) {
     if (typeof b === 'string')
-      b = new _BN(b);
+      b = new BN(b);
     else if (typeof b === 'number')
-      b = new _BN(b.toString());
+      b = new BN(b.toString());
     return this['_' + name](b);
   };
   BN.prototype[name] = f;
 };
 
-_BN.prototype.gt = function(b) {
+BN.prototype.gt = function(b) {
   return this.cmp(b) > 0;
 };
 
-_BN.prototype.lt = function(b) {
+BN.prototype.lt = function(b) {
   return this.cmp(b) < 0;
 };
 
@@ -121,8 +220,4 @@ decorate('cmp');
 decorate('gt');
 decorate('lt');
 
-BN.prototype.toNumber = function() {
-  return parseInt(this['toString'](10), 10);
-};
-
 module.exports = BN;
diff --git a/lib/crypto/ecdsa.js b/lib/crypto/ecdsa.js
index 8735367..b0d7260 100644
--- a/lib/crypto/ecdsa.js
+++ b/lib/crypto/ecdsa.js
@@ -1,11 +1,20 @@
+/**
+ * @file ecdsa.js
+ * @license MIT
+ *
+ * Copyright (c) 2014 reddit, Inc.
+ * Copyright (c) 2014 Ryan X. Charles
+ * Copyright (c) 2014 BitPay, Inc.
+ */
 'use strict';
 
 var BN = require('./bn');
 var Point = require('./point');
 var Signature = require('./signature');
-var Random = require('./random');
 var PublicKey = require('../publickey');
 var PrivateKey = require('../privatekey');
+var Random = require('./random');
+var Hash = require('./hash');
 
 var ECDSA = function ECDSA(obj) {
   if (!(this instanceof ECDSA)) {
@@ -18,16 +27,17 @@ var ECDSA = function ECDSA(obj) {
 
 ECDSA.prototype.set = function(obj) {
   this.hashbuf = obj.hashbuf || this.hashbuf;
+  this.endian = obj.endian || this.endian; //the endianness of hashbuf
   this.privkey = obj.privkey || this.privkey;
-  this.pubkey = obj.pubkey || this.pubkey;
+  this.pubkey = obj.pubkey || (this.privkey ? this.privkey.publicKey : this.pubkey);
   this.sig = obj.sig || this.sig;
   this.k = obj.k || this.k;
   this.verified = obj.verified || this.verified;
   return this;
 };
 
-ECDSA.prototype.privkey2pubkey = function(){
-  this.pubkey = PublicKey.fromPrivateKey(this.privkey);
+ECDSA.prototype.privkey2pubkey = function() {
+  this.pubkey = this.privkey.toPublicKey();
 };
 
 ECDSA.prototype.calci = function() {
@@ -37,9 +47,10 @@ ECDSA.prototype.calci = function() {
     try {
       Qprime = this.sig2pubkey();
     } catch (e) {
-      console.log(e);
+      console.error(e);
       continue;
     }
+
     if (Qprime.point.eq(this.pubkey.point)) {
       this.sig.compressed = this.pubkey.compressed;
       return this;
@@ -52,16 +63,21 @@ ECDSA.prototype.calci = function() {
 
 ECDSA.prototype.fromString = function(str) {
   var obj = JSON.parse(str);
-  if (obj.hashbuf)
+  if (obj.hashbuf) {
     this.hashbuf = new Buffer(obj.hashbuf, 'hex');
-  if (obj.pubkey)
+  }
+  if (obj.pubkey) {
     this.pubkey = PublicKey.fromString(obj.pubkey);
-  if (obj.privkey)
+  }
+  if (obj.privkey) {
     this.privkey = PrivateKey.fromString(obj.privkey);
-  if (obj.sig)
+  }
+  if (obj.sig) {
     this.sig = Signature().fromString(obj.sig);
-  if (obj.k)
+  }
+  if (obj.k) {
     this.k = BN(obj.k, 10);
+  }
   return this;
 };
 
@@ -75,6 +91,37 @@ ECDSA.prototype.randomK = function() {
   return this;
 };
 
+// https://tools.ietf.org/html/rfc6979#section-3.2
+ECDSA.prototype.deterministicK = function(badrs) {
+  var v = new Buffer(32);
+  v.fill(0x01);
+  var k = new Buffer(32);
+  k.fill(0x00);
+  var x = this.privkey.bn.toBuffer({size: 32});
+  k = Hash.sha256hmac(Buffer.concat([v, new Buffer([0x00]), x, this.hashbuf]), k);
+  v = Hash.sha256hmac(v, k);
+  k = Hash.sha256hmac(Buffer.concat([v, new Buffer([0x01]), x, this.hashbuf]), k);
+  v = Hash.sha256hmac(v, k);
+  v = Hash.sha256hmac(v, k);
+  var T = BN().fromBuffer(v);
+  var N = Point.getN();
+
+  // if r or s were invalid when this function was used in signing,
+  // we do not want to actually compute r, s here for efficiency, so,
+  // we can increment badrs. explained at end of RFC 6979 section 3.2
+  if (typeof badrs === 'undefined')
+    badrs = 0;
+  // also explained in 3.2, we must ensure T is in the proper range (0, N)
+  for (var i = 0; i < badrs || !(T.lt(N) && T.gt(0)); i++) {
+    k = Hash.sha256hmac(Buffer.concat([v, new Buffer([0x00])]), k);
+    v = Hash.sha256hmac(v, k);
+    T = BN().fromBuffer(v);
+  }
+
+  this.k = T;
+  return this;
+};
+
 // Information about public key recovery:
 // https://bitcointalk.org/index.php?topic=6430.0
 // http://stackoverflow.com/questions/19665491/how-do-i-get-an-ecdsa-public-key-from-just-a-bitcoin-signature-sec1-4-1-6-k
@@ -123,8 +170,9 @@ ECDSA.prototype.sig2pubkey = function() {
 };
 
 ECDSA.prototype.sigError = function() {
-  if (!Buffer.isBuffer(this.hashbuf) || this.hashbuf.length !== 32)
+  if (!Buffer.isBuffer(this.hashbuf) || this.hashbuf.length !== 32) {
     return 'hashbuf must be a 32 byte buffer';
+  }
 
   var r = this.sig.r;
   var s = this.sig.s;
@@ -132,7 +180,7 @@ ECDSA.prototype.sigError = function() {
    || !(s.gt(0) && s.lt(Point.getN())))
     return 'r and s not in range';
 
-  var e = BN().fromBuffer(this.hashbuf);
+  var e = BN().fromBuffer(this.hashbuf, this.endian ? {endian: this.endian} : undefined);
   var n = Point.getN();
   var sinv = s.invm(n);
   var u1 = sinv.mul(e).mod(n);
@@ -151,11 +199,8 @@ ECDSA.prototype.sigError = function() {
 ECDSA.prototype.sign = function() {
   var hashbuf = this.hashbuf;
   var privkey = this.privkey;
-  var k = this.k;
-  var d = privkey.bn;
 
-  if (!k)
-    throw new Error('You must specify k - perhaps you should run signRandomK instead');
+  var d = privkey.bn;
 
   if (!hashbuf || !privkey || !d)
     throw new Error('invalid parameters');
@@ -165,60 +210,79 @@ ECDSA.prototype.sign = function() {
 
   var N = Point.getN();
   var G = Point.getG();
-  var e = BN().fromBuffer(hashbuf);
+  var e = BN().fromBuffer(hashbuf, this.endian ? {endian: this.endian} : undefined);
 
+  // try different values of k until r, s are valid
+  var badrs = 0;
   do {
+    if (!this.k || badrs > 0)
+      this.deterministicK(badrs);
+    badrs++;
+    var k = this.k;
     var Q = G.mul(k);
     var r = Q.x.mod(N);
     var s = k.invm(N).mul(e.add(d.mul(r))).mod(N);
   } while (r.cmp(0) <= 0 || s.cmp(0) <= 0);
 
-  this.sig = new Signature({r: r, s: s, compressed: this.privkey.compressed});
-  return this.sig;
+  //enforce low s
+  //see BIP 62, "low S values in signatures"
+  if (s.gt(BN().fromBuffer(new Buffer('7FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF5D576E7357A4501DDFE92F46681B20A0', 'hex')))) {
+    s = Point.getN().sub(s);
+  }
+
+  this.sig = new Signature({r: r, s: s, compressed: this.pubkey.compressed});
+  return this;
 };
 
 ECDSA.prototype.signRandomK = function() {
-  var k = this.randomK();
+  this.randomK();
   return this.sign();
 };
 
 ECDSA.prototype.toString = function() {
   var obj = {};
-  if (this.hashbuf)
+  if (this.hashbuf) {
     obj.hashbuf = this.hashbuf.toString('hex');
-  if (this.pubkey)
-    obj.pubkey = this.pubkey.toString();
-  if (this.privkey)
+  }
+  if (this.privkey) {
     obj.privkey = this.privkey.toString();
-  if (this.keypair)
-    obj.keypair = this.keypair.toString();
-  if (this.sig)
+  }
+  if (this.pubkey) {
+    obj.pubkey = this.pubkey.toString();
+  }
+  if (this.sig) {
     obj.sig = this.sig.toString();
-  if (this.k)
+  }
+  if (this.k) {
     obj.k = this.k.toString();
+  }
   return JSON.stringify(obj);
 };
 
 ECDSA.prototype.verify = function() {
   if (!this.sigError())
-    return true;
+    this.verified = true;
   else
-    return false;
+    this.verified = false;
+  return this;
 };
 
-ECDSA.sign = function(hashbuf, privkey) {
+ECDSA.sign = function(hashbuf, privkey, endian) {
+  console.log('Signing', hashbuf, 'with key', privkey);
   return ECDSA().set({
     hashbuf: hashbuf,
+    endian: endian,
     privkey: privkey
-  }).signRandomK();
+  }).sign().sig;
 };
 
-ECDSA.verify = function(hashbuf, sig, pubkey) {
+ECDSA.verify = function(hashbuf, sig, pubkey, endian) {
   return ECDSA().set({
     hashbuf: hashbuf,
+    endian: endian,
     sig: sig,
     pubkey: pubkey
-  }).verify();
+  }).verify().verified;
 };
 
 module.exports = ECDSA;
diff --git a/lib/crypto/signature.js b/lib/crypto/signature.js
index 7d9e725..36c58ed 100644
--- a/lib/crypto/signature.js
+++ b/lib/crypto/signature.js
@@ -1,3 +1,11 @@
+/**
+ * @file ecdsa.js
+ * @license MIT
+ *
+ * Copyright (c) 2014 reddit, Inc.
+ * Copyright (c) 2014 Ryan X. Charles
+ * Copyright (c) 2014 BitPay, Inc.
+ */
 'use strict';
 
 var BN = require('./bn');
@@ -168,4 +176,9 @@ Signature.prototype.toString = function() {
   return buf.toString('hex');
 };
 
+Signature.SIGHASH_ALL = 0x01;
+Signature.SIGHASH_NONE = 0x02;
+Signature.SIGHASH_SINGLE = 0x03;
+Signature.SIGHASH_ANYONECANPAY = 0x80;
+
 module.exports = Signature;
diff --git a/test/crypto/ecdsa.js b/test/crypto/ecdsa.js
index e41559e..e764316 100644
--- a/test/crypto/ecdsa.js
+++ b/test/crypto/ecdsa.js
@@ -1,24 +1,23 @@
-'use strict';
-
+var ECDSA = require('../../lib/crypto/ecdsa');
+var Hash = require('../../lib/crypto/hash');
+var Privkey = require('../../lib/privatekey');
+var Pubkey = require('../../lib/publickey');
+var Signature = require('../../lib/crypto/signature');
+var Point = require('../../lib/crypto/point');
+var BN = require('../../lib/crypto/bn');
+var point = require('../../lib/crypto/point');
 var should = require('chai').should();
-var bitcore = require('../..');
-var ECDSA = bitcore.crypto.ECDSA;
-var Hash = bitcore.crypto.Hash;
-var Signature = bitcore.crypto.Signature;
-var PrivateKey = bitcore.PrivateKey;
-var PublicKey = bitcore.PublicKey;
-var BN = bitcore.crypto.BN;
+var vectors = require('./vectors/ecdsa');
 
-describe('ECDSA', function() {
+describe("ECDSA", function() {
 
   it('should create a blank ecdsa', function() {
     var ecdsa = new ECDSA();
-    should.exist(ecdsa);
   });
 
   var ecdsa = new ECDSA();
   ecdsa.hashbuf = Hash.sha256(new Buffer('test data'));
-  ecdsa.privkey = new PrivateKey(BN().fromBuffer(new Buffer('fee0a1f7afebf9d2a5a80c0c98a31c709681cce195cbcd06342b517970c0be1e', 'hex')));
+  ecdsa.privkey = new Privkey(BN().fromBuffer(new Buffer('fee0a1f7afebf9d2a5a80c0c98a31c709681cce195cbcd06342b517970c0be1e', 'hex')));
   ecdsa.privkey2pubkey();
 
   describe('#set', function() {
@@ -42,11 +41,12 @@ describe('ECDSA', function() {
       var hashbuf = Hash.sha256(new Buffer('some data'));
       var r = BN('71706645040721865894779025947914615666559616020894583599959600180037551395766', 10);
       var s = BN('109412465507152403114191008482955798903072313614214706891149785278625167723646', 10);
-      var ecdsa = new ECDSA();
-      ecdsa.privkey = PrivateKey(BN().fromBuffer(Hash.sha256(new Buffer('test'))));
-      ecdsa.privkey2pubkey();
-      ecdsa.hashbuf = hashbuf;
-      ecdsa.sig = new Signature({r: r, s: s});
+      var ecdsa = new ECDSA({
+        privkey: Privkey(BN().fromBuffer(Hash.sha256(new Buffer('test')))),
+        hashbuf: hashbuf,
+        sig: new Signature({r: r, s: s})
+      });
+
       ecdsa.calci();
       ecdsa.sig.i.should.equal(1);
     });
@@ -60,7 +60,6 @@ describe('ECDSA', function() {
       var ecdsa2 = new ECDSA();
       ecdsa2.fromString(str);
       should.exist(ecdsa.hashbuf);
-      should.exist(ecdsa.pubkey);
       should.exist(ecdsa.privkey);
     });
 
@@ -85,11 +84,59 @@ describe('ECDSA', function() {
 
   });
 
+  describe('#deterministicK', function() {
+
+    it('should generate the same deterministic k', function() {
+      ecdsa.deterministicK();
+      ecdsa.k.toBuffer().toString('hex').should.equal('fcce1de7a9bcd6b2d3defade6afa1913fb9229e3b7ddf4749b55c4848b2a196e');
+    });
+
+    it('should generate the same deterministic k if badrs is set', function() {
+      ecdsa.deterministicK(0);
+      ecdsa.k.toBuffer().toString('hex').should.equal('fcce1de7a9bcd6b2d3defade6afa1913fb9229e3b7ddf4749b55c4848b2a196e');
+      ecdsa.deterministicK(1);
+      ecdsa.k.toBuffer().toString('hex').should.not.equal('fcce1de7a9bcd6b2d3defade6afa1913fb9229e3b7ddf4749b55c4848b2a196e');
+      ecdsa.k.toBuffer().toString('hex').should.equal('6f4dcca6fa7a137ae9d110311905013b3c053c732ad18611ec2752bb3dcef9d8');
+    });
+
+    it('should compute this test vector correctly', function() {
+      // test fixture from bitcoinjs
+      // https://github.com/bitcoinjs/bitcoinjs-lib/blob/10630873ebaa42381c5871e20336fbfb46564ac8/test/fixtures/ecdsa.json#L6
+      var ecdsa = new ECDSA();
+      ecdsa.hashbuf = Hash.sha256(new Buffer('Everything should be made as simple as possible, but not simpler.'));
+      ecdsa.privkey = Privkey(BN(1));
+      ecdsa.privkey2pubkey();
+      ecdsa.deterministicK();
+      ecdsa.k.toBuffer().toString('hex').should.equal('ec633bd56a5774a0940cb97e27a9e4e51dc94af737596a0c5cbb3d30332d92a5');
+      ecdsa.sign();
+      ecdsa.sig.r.toString().should.equal('23362334225185207751494092901091441011938859014081160902781146257181456271561');
+      ecdsa.sig.s.toString().should.equal('50433721247292933944369538617440297985091596895097604618403996029256432099938');
+    });
+
+  });
+
   describe('#sig2pubkey', function() {
 
     it('should calculate the correct public key', function() {
       ecdsa.k = BN('114860389168127852803919605627759231199925249596762615988727970217268189974335', 10);
       ecdsa.sign();
+      ecdsa.sig.i = 0;
+      var pubkey = ecdsa.sig2pubkey();
+      pubkey.point.eq(ecdsa.pubkey.point).should.equal(true);
+    });
+
+    it('should calculate the correct public key for this signature with low s', function() {
+      ecdsa.k = BN('114860389168127852803919605627759231199925249596762615988727970217268189974335', 10);
+      ecdsa.sig = Signature().fromString('3045022100ec3cfe0e335791ad278b4ec8eac93d0347a97877bb1d54d35d189e225c15f6650220278cf15b05ce47fb37d2233802899d94c774d5480bba9f0f2d996baa13370c43');
+      ecdsa.sig.i = 0;
+      var pubkey = ecdsa.sig2pubkey();
+      pubkey.point.eq(ecdsa.pubkey.point).should.equal(true);
+    });
+
+    it('should calculate the correct public key for this signature with high s', function() {
+      ecdsa.k = BN('114860389168127852803919605627759231199925249596762615988727970217268189974335', 10);
+      ecdsa.sign();
+      ecdsa.sig = Signature().fromString('3046022100ec3cfe0e335791ad278b4ec8eac93d0347a97877bb1d54d35d189e225c15f665022100d8730ea4fa31b804c82ddcc7fd766269f33a079ea38e012c9238f2e2bcff34fe');
       ecdsa.sig.i = 1;
       var pubkey = ecdsa.sig2pubkey();
       pubkey.point.eq(ecdsa.pubkey.point).should.equal(true);
@@ -104,22 +151,28 @@ describe('ECDSA', function() {
       ecdsa.sigError().should.equal('hashbuf must be a 32 byte buffer');
     });
 
+    it.skip('should return an error if the pubkey is invalid', function() {
+      var ecdsa = new ECDSA();
+      ecdsa.hashbuf = Hash.sha256(new Buffer('test'));
+      ecdsa.sigError().indexOf("Invalid pubkey").should.equal(0);
+    });
+
     it('should return an error if r, s are invalid', function() {
       var ecdsa = new ECDSA();
       ecdsa.hashbuf = Hash.sha256(new Buffer('test'));
-      var pk = PublicKey.fromDER(new Buffer('041ff0fe0f7b15ffaa85ff9f4744d539139c252a49710fb053bb9f2b933173ff9a7baad41d04514751e6851f5304fd243751703bed21b914f6be218c0fa354a341', 'hex'));
+      var pk = Pubkey.fromDER(new Buffer('041ff0fe0f7b15ffaa85ff9f4744d539139c252a49710fb053bb9f2b933173ff9a7baad41d04514751e6851f5304fd243751703bed21b914f6be218c0fa354a341', 'hex'));
       ecdsa.pubkey = pk;
       ecdsa.sig = new Signature();
       ecdsa.sig.r = BN(0);
       ecdsa.sig.s = BN(0);
-      ecdsa.sigError().should.equal('r and s not in range');
+      ecdsa.sigError().should.equal("r and s not in range");
     });
 
     it('should return an error if the signature is incorrect', function() {
       ecdsa.sig = new Signature();
       ecdsa.sig.fromString('3046022100e9915e6236695f093a4128ac2a956c40ed971531de2f4f41ba05fac7e2bd019c02210094e6a4a769cc7f2a8ab3db696c7cd8d56bcdbfff860a8c81de4bc6a798b90827');
       ecdsa.sig.r = ecdsa.sig.r.add(BN(1));
-      ecdsa.sigError().should.equal('Invalid signature');
+      ecdsa.sigError().should.equal("Invalid signature");
     });
 
   });
@@ -129,13 +182,12 @@ describe('ECDSA', function() {
     it('should create a valid signature', function() {
       ecdsa.randomK();
       ecdsa.sign();
-      ecdsa.verify().should.equal(true);
+      ecdsa.verify().verified.should.equal(true);
     });
 
     it('should should throw an error if hashbuf is not 32 bytes', function() {
       var ecdsa2 = ECDSA().set({
         hashbuf: ecdsa.hashbuf.slice(0, 31),
-        pubkey: ecdsa.pubkey,
         privkey: ecdsa.privkey
       });
       ecdsa2.randomK();
@@ -144,13 +196,29 @@ describe('ECDSA', function() {
       }).should.throw('hashbuf must be a 32 byte buffer');
     });
 
+    it('should default to deterministicK', function() {
+      var ecdsa2 = new ECDSA(ecdsa);
+      ecdsa2.k = undefined;
+      var called = 0;
+      var deterministicK = ecdsa2.deterministicK.bind(ecdsa2);
+      ecdsa2.deterministicK = function() {
+        deterministicK();
+        called++;
+      };
+      ecdsa2.sign();
+      called.should.equal(1);
+    });
+
   });
 
   describe('#signRandomK', function() {
 
-    it('should produce a signature', function() {
+    it('should produce a signature, and be different when called twice', function() {
       ecdsa.signRandomK();
       should.exist(ecdsa.sig);
+      var ecdsa2 = ECDSA(ecdsa);
+      ecdsa2.signRandomK();
+      ecdsa.sig.toString().should.not.equal(ecdsa2.sig.toString());
     });
 
   });
@@ -169,12 +237,12 @@ describe('ECDSA', function() {
     it('should verify a signature that was just signed', function() {
       ecdsa.sig = new Signature();
       ecdsa.sig.fromString('3046022100e9915e6236695f093a4128ac2a956c40ed971531de2f4f41ba05fac7e2bd019c02210094e6a4a769cc7f2a8ab3db696c7cd8d56bcdbfff860a8c81de4bc6a798b90827');
-      ecdsa.verify().should.equal(true);
+      ecdsa.verify().verified.should.equal(true);
     });
 
     it('should verify this known good signature', function() {
       ecdsa.signRandomK();
-      ecdsa.verify().should.equal(true);
+      ecdsa.verify().verified.should.equal(true);
     });
 
   });
@@ -197,6 +265,53 @@ describe('ECDSA', function() {
       ECDSA.verify(ecdsa.hashbuf, fakesig, ecdsa.pubkey).should.equal(false);
     });
 
+    it('should work with big and little endian', function() {
+      var sig = ECDSA.sign(ecdsa.hashbuf, ecdsa.privkey, 'big');
+      ECDSA.verify(ecdsa.hashbuf, sig, ecdsa.pubkey, 'big').should.equal(true);
+      ECDSA.verify(ecdsa.hashbuf, sig, ecdsa.pubkey, 'little').should.equal(false);
+      sig = ECDSA.sign(ecdsa.hashbuf, ecdsa.privkey, 'little');
+      ECDSA.verify(ecdsa.hashbuf, sig, ecdsa.pubkey, 'big').should.equal(false);
+      ECDSA.verify(ecdsa.hashbuf, sig, ecdsa.pubkey, 'little').should.equal(true);
+    });
+
+  });
+
+  describe('vectors', function() {
+
+    vectors.valid.forEach(function(obj, i) {
+      it('should validate valid vector ' + i, function() {
+        var ecdsa = ECDSA().set({
+          privkey: Privkey(BN().fromBuffer(new Buffer(obj.d, 'hex'))),
+          k: BN().fromBuffer(new Buffer(obj.k, 'hex')),
+          hashbuf: Hash.sha256(new Buffer(obj.message)),
+          sig: Signature().set({
+            r: BN(obj.signature.r),
+            s: BN(obj.signature.s),
+            i: obj.i
+          })
+        });
+        var ecdsa2 = ECDSA(ecdsa);
+        ecdsa2.k = undefined;
+        ecdsa2.sign();
+        ecdsa2.calci();
+        ecdsa2.k.toString().should.equal(ecdsa.k.toString());
+        ecdsa2.sig.toString().should.equal(ecdsa.sig.toString());
+        ecdsa2.sig.i.should.equal(ecdsa.sig.i);
+        ecdsa.verify().verified.should.equal(true);
+      });
+    });
+    
+    vectors.invalid.sigError.forEach(function(obj, i) {
+      it('should validate invalid.sigError vector ' + i + ': ' + obj.description, function() {
+        var ecdsa = ECDSA().set({
+          pubkey: Pubkey.fromPoint(point.fromX(true, 1)),
+          sig: Signature(BN(obj.signature.r), BN(obj.signature.s)),
+          hashbuf: Hash.sha256(new Buffer(obj.message))
+        });
+        ecdsa.sigError().should.equal(obj.exception);
+      });
+    });
+
   });
 
 });
diff --git a/test/crypto/vectors/ecdsa.json b/test/crypto/vectors/ecdsa.json
new file mode 100644
index 0000000..fb2bcea
--- /dev/null
+++ b/test/crypto/vectors/ecdsa.json
@@ -0,0 +1,158 @@
+{
+  "valid": [
+    {
+      "d": "01",
+      "k": "ec633bd56a5774a0940cb97e27a9e4e51dc94af737596a0c5cbb3d30332d92a5",
+      "message": "Everything should be made as simple as possible, but not simpler.",
+      "i": 0,
+      "signature": {
+        "r": "23362334225185207751494092901091441011938859014081160902781146257181456271561",
+        "s": "50433721247292933944369538617440297985091596895097604618403996029256432099938"
+      }
+    },
+    {
+      "d": "fffffffffffffffffffffffffffffffebaaedce6af48a03bbfd25e8cd0364140",
+      "k": "9dc74cbfd383980fb4ae5d2680acddac9dac956dca65a28c80ac9c847c2374e4",
+      "message": "Equations are more important to me, because politics is for the present, but an equation is something for eternity.",
+      "i": 0,
+      "signature": {
+        "r": "38341707918488238920692284707283974715538935465589664377561695343399725051885",
+        "s": "3180566392414476763164587487324397066658063772201694230600609996154610926757"
+      }
+    },
+    {
+      "d": "fffffffffffffffffffffffffffffffebaaedce6af48a03bbfd25e8cd0364140",
+      "k": "fd27071f01648ebbdd3e1cfbae48facc9fa97edc43bbbc9a7fdc28eae13296f5",
+      "message": "Not only is the Universe stranger than we think, it is stranger than we can think.",
+      "i": 0,
+      "signature": {
+        "r": "115464191557905790016094131873849783294273568009648050793030031933291767741904",
+        "s": "50562520307781850052192542766631199590053690478900449960232079510155113443971"
+      }
+    },
+    {
+      "d": "0000000000000000000000000000000000000000000000000000000000000001",
+      "k": "f0cd2ba5fc7c183de589f6416220a36775a146740798756d8d949f7166dcc87f",
+      "message": "How wonderful that we have met with a paradox. Now we have some hope of making progress.",
+      "i": 1,
+      "signature": {
+        "r": "87230998027579607140680851455601772643840468630989315269459846730712163783123",
+        "s": "53231320085894623106179381504478252331065330583563809963303318469380290929875"
+      }
+    },
+    {
+      "d": "69ec59eaa1f4f2e36b639716b7c30ca86d9a5375c7b38d8918bd9c0ebc80ba64",
+      "k": "6bb4a594ad57c1aa22dbe991a9d8501daf4688bf50a4892ef21bd7c711afda97",
+      "message": "Computer science is no more about computers than astronomy is about telescopes.",
+      "i": 0,
+      "signature": {
+        "r": "51348483531757779992459563033975330355971795607481991320287437101831125115997",
+        "s": "6277080015686056199074771961940657638578000617958603212944619747099038735862"
+      }
+    },
+    {
+      "d": "00000000000000000000000000007246174ab1e92e9149c6e446fe194d072637",
+      "k": "097b5c8ee22c3ea78a4d3635e0ff6fe85a1eb92ce317ded90b9e71aab2b861cb",
+      "message": "...if you aren't, at any given time, scandalized by code you wrote five or even three years ago, you're not learning anywhere near enough",
+      "i": 1,
+      "signature": {
+        "r": "113979859486826658566290715281614250298918272782414232881639314569529560769671",
+        "s": "6517071009538626957379450615706485096874328019806177698938278220732027419959"
+      }
+    },
+    {
+      "d": "000000000000000000000000000000000000000000056916d0f9b31dc9b637f3",
+      "k": "19355c36c8cbcdfb2382e23b194b79f8c97bf650040fc7728dfbf6b39a97c25b",
+      "message": "The question of whether computers can think is like the question of whether submarines can swim.",
+      "i": 1,
+      "signature": {
+        "r": "93122007060065279508564838030979550535085999589142852106617159184757394422777",
+        "s": "3078539468410661027472930027406594684630312677495124015420811882501887769839"
+      }
+    }
+  ],
+  "invalid": {
+    "sigError": [
+      {
+        "description": "The wrong signature",
+        "exception": "Invalid signature",
+        "d": "01",
+        "message": "foo",
+        "signature": {
+          "r": "38341707918488238920692284707283974715538935465589664377561695343399725051885",
+          "s": "3180566392414476763164587487324397066658063772201694230600609996154610926757"
+        }
+      },
+      {
+        "description": "Invalid r value (< 0)",
+        "exception": "r and s not in range",
+        "d": "01",
+        "message": "foo",
+        "signature": {
+          "r": "-1",
+          "s": "2"
+        }
+      },
+      {
+        "description": "Invalid r value (== 0)",
+        "exception": "r and s not in range",
+        "d": "01",
+        "message": "foo",
+        "signature": {
+          "r": "0",
+          "s": "2"
+        }
+      },
+      {
+        "description": "Invalid r value (>= n)",
+        "exception": "r and s not in range",
+        "d": "01",
+        "message": "foo",
+        "signature": {
+          "r": "115792089237316195423570985008687907852837564279074904382605163141518161494337",
+          "s": "2"
+        }
+      },
+      {
+        "description": "Invalid s value (< 0)",
+        "exception": "r and s not in range",
+        "d": "01",
+        "message": "foo",
+        "signature": {
+          "r": "2",
+          "s": "-1"
+        }
+      },
+      {
+        "description": "Invalid s value (== 0)",
+        "exception": "r and s not in range",
+        "d": "01",
+        "message": "foo",
+        "signature": {
+          "r": "2",
+          "s": "0"
+        }
+      },
+      {
+        "description": "Invalid s value (>= n)",
+        "exception": "r and s not in range",
+        "d": "01",
+        "message": "foo",
+        "signature": {
+          "r": "2",
+          "s": "115792089237316195423570985008687907852837564279074904382605163141518161494337"
+        }
+      },
+      {
+        "description": "Invalid r, s values (r = s = -n)",
+        "exception": "r and s not in range",
+        "d": "01",
+        "message": "foo",
+        "signature": {
+          "r": "-115792089237316195423570985008687907852837564279074904382605163141518161494337",
+          "s": "-115792089237316195423570985008687907852837564279074904382605163141518161494337"
+        }
+      }
+    ]
+  }
+}