diff --git a/browser/bundle.js b/browser/bundle.js
index 71b028b..7577a5b 100644
--- a/browser/bundle.js
+++ b/browser/bundle.js
@@ -4558,7 +4558,6 @@ var Point = imports.Point || require('./Point');
 var SecureRandom = imports.SecureRandom || require('./SecureRandom');
 var bignum = imports.bignum || require('bignum');
 var networks = require('../networks');
-var BufferPut = require('bufferput');
 
 var secp256k1_n = new bignum('FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFEBAAEDCE6AF48A03BBFD25E8CD0364141', 16);
 var secp256k1_Gx = new bignum('79BE667EF9DCBBAC55A06295CE870B07029BFCDB2DCE28D959F2815B16F81798', 16);
@@ -4572,7 +4571,8 @@ var HierarchicalKey = function(bytes) {
   if (typeof bytes == 'undefined' || bytes == 'mainnet' || bytes == 'livenet') {
     bytes = 'livenet';
     this.version = networks['livenet'].hkeyPrivateVersion;
-  } else if (bytes == 'testnet') {
+  }
+  else if (bytes == 'testnet') {
     this.version = networks['testnet'].hkeyPrivateVersion;
   }
   if (bytes == 'livenet' || bytes == 'testnet') {
@@ -4587,12 +4587,12 @@ var HierarchicalKey = function(bytes) {
     this.buildExtendedPrivateKey();
     return;
   }
-
+  
   // decode base58
   if (typeof bytes === 'string') {
     var decoded = base58.decode(bytes);
     if (decoded.length != 82)
-      throw new Error('Not enough data, expected 82 and received ' + decoded.length);
+      throw new Error('Not enough data, expected 82 and received '+decoded.length);
     var checksum = decoded.slice(78, 82);
     bytes = decoded.slice(0, 78);
 
@@ -4603,7 +4603,7 @@ var HierarchicalKey = function(bytes) {
     }
   }
 
-  if (bytes !== undefined && bytes !== null)
+  if (bytes !== undefined && bytes !== null) 
     this.initFromBytes(bytes);
 }
 
@@ -4613,9 +4613,9 @@ HierarchicalKey.seed = function(bytes, network) {
 
   if (!Buffer.isBuffer(bytes))
     bytes = new Buffer(bytes, 'hex'); //if not buffer, assume hex
-  if (bytes.length < 128 / 8)
+  if (bytes.length < 128/8)
     return false; //need more entropy
-  if (bytes.length > 512 / 8)
+  if (bytes.length > 512/8)
     return false;
   var hash = coinUtil.sha512hmac(bytes, new Buffer('Bitcoin seed'));
 
@@ -4639,23 +4639,23 @@ HierarchicalKey.seed = function(bytes, network) {
 
 HierarchicalKey.prototype.initFromBytes = function(bytes) {
   // Both pub and private extended keys are 78 bytes
-  if (bytes.length != 78) throw new Error('not enough data');
+  if(bytes.length != 78) throw new Error('not enough data');
 
-  this.version = u32(bytes.slice(0, 4));
-  this.depth = u8(bytes.slice(4, 5));
+  this.version      = u32(bytes.slice(0, 4));
+  this.depth        = u8(bytes.slice(4, 5));
   this.parentFingerprint = bytes.slice(5, 9);
-  this.childIndex = u32(bytes.slice(9, 13));
-  this.chainCode = bytes.slice(13, 45);
-
+  this.childIndex    = u32(bytes.slice(9, 13));
+  this.chainCode     = bytes.slice(13, 45);
+  
   var keyBytes = bytes.slice(45, 78);
 
-  var isPrivate =
-    (this.version == networks['livenet'].hkeyPrivateVersion ||
-    this.version == networks['testnet'].hkeyPrivateVersion);
+  var isPrivate = 
+    (this.version == networks['livenet'].hkeyPrivateVersion  ||
+     this.version == networks['testnet'].hkeyPrivateVersion  );
 
-  var isPublic =
-    (this.version == networks['livenet'].hkeyPublicVersion ||
-    this.version == networks['testnet'].hkeyPublicVersion);
+  var isPublic = 
+    (this.version == networks['livenet'].hkeyPublicVersion  ||
+     this.version == networks['testnet'].hkeyPublicVersion  );
 
   if (isPrivate && keyBytes[0] == 0) {
     this.eckey = new Key();
@@ -4681,30 +4681,34 @@ HierarchicalKey.prototype.buildExtendedPublicKey = function() {
   this.extendedPublicKey = new Buffer([]);
 
   var v = null;
-  switch (this.version) {
-    case networks['livenet'].hkeyPublicVersion:
-    case networks['livenet'].hkeyPrivateVersion:
-      v = networks['livenet'].hkeyPublicVersion;
-      break;
-    case networks['testnet'].hkeyPublicVersion:
-    case networks['testnet'].hkeyPrivateVersion:
-      v = networks['testnet'].hkeyPublicVersion;
-      break;
-    default:
-      throw new Error('Unknown version');
+  switch(this.version) {
+  case networks['livenet'].hkeyPublicVersion:
+  case networks['livenet'].hkeyPrivateVersion:
+    v = networks['livenet'].hkeyPublicVersion;
+    break;
+  case networks['testnet'].hkeyPublicVersion:
+  case networks['testnet'].hkeyPrivateVersion:
+    v = networks['testnet'].hkeyPublicVersion;
+    break;
+   default:
+    throw new Error('Unknown version');
   }
 
-  var r = new BufferPut();
-  r = r.word32be(v);
-  r = r.word8(this.depth);
-  r = r.put(this.parentFingerprint);
-  r = r.word32be(this.childIndex);
-  r = r.put(this.chainCode);
-  r = r.put(this.eckey.public);
-
-
-  this.extendedPublicKey = new Buffer(0);
-  this.extendedPublicKey = r.buffer();
+  // Version
+  this.extendedPublicKey = Buffer.concat([
+    new Buffer([v >> 24]),
+    new Buffer([(v >> 16) & 0xff]),
+    new Buffer([(v >> 8) & 0xff]),
+    new Buffer([v & 0xff]),
+    new Buffer([this.depth]),
+    this.parentFingerprint,
+    new Buffer([this.childIndex >>> 24]),
+    new Buffer([(this.childIndex >>> 16) & 0xff]),
+    new Buffer([(this.childIndex >>> 8) & 0xff]),
+    new Buffer([this.childIndex & 0xff]),
+    this.chainCode,
+    this.eckey.public
+  ]);
 }
 
 HierarchicalKey.prototype.extendedPublicKeyString = function(format) {
@@ -4726,16 +4730,21 @@ HierarchicalKey.prototype.buildExtendedPrivateKey = function() {
 
   var v = this.version;
 
-  var r = new BufferPut();
-  r = r.word32be(v);
-  r = r.word8(this.depth);
-  r = r.put(this.parentFingerprint);
-  r = r.word32be(this.childIndex);
-  r = r.put(this.chainCode);
-  r = r.word8(0);
-  r = r.put(this.eckey.private);
-
-  this.extendedPrivateKey = r.buffer(); 
+  this.extendedPrivateKey = Buffer.concat([
+    new Buffer([v >> 24]),
+    new Buffer([(v >> 16) & 0xff]),
+    new Buffer([(v >> 8) & 0xff]),
+    new Buffer([v & 0xff]),
+    new Buffer([this.depth]),
+    this.parentFingerprint,
+    new Buffer([this.childIndex >>> 24]),
+    new Buffer([(this.childIndex >>> 16) & 0xff]),
+    new Buffer([(this.childIndex >>> 8) & 0xff]),
+    new Buffer([this.childIndex & 0xff]),
+    this.chainCode,
+    new Buffer([0]),
+    this.eckey.private
+  ]);
 }
 
 HierarchicalKey.prototype.extendedPrivateKeyString = function(format) {
@@ -4763,17 +4772,16 @@ HierarchicalKey.prototype.derive = function(path) {
   for (var i in e) {
     var c = e[i];
 
-    if (i == 0) {
+    if (i == 0 ) {
       if (c != 'm') throw new Error('invalid path');
       continue;
     }
 
-    var usePrivate = (c.length > 1) && (c[c.length - 1] == '\'');
+    var usePrivate = (c.length > 1) && (c[c.length-1] == '\'');
     var childIndex = parseInt(usePrivate ? c.slice(0, c.length - 1) : c) & 0x7fffffff;
 
-    if (usePrivate) {
+    if (usePrivate)
       childIndex += 0x80000000;
-    }
 
     hkey = hkey.deriveChild(childIndex);
   }
@@ -4785,15 +4793,15 @@ HierarchicalKey.prototype.deriveChild = function(i) {
   var ib = [];
   ib.push((i >> 24) & 0xff);
   ib.push((i >> 16) & 0xff);
-  ib.push((i >> 8) & 0xff);
+  ib.push((i >>  8) & 0xff);
   ib.push(i & 0xff);
   ib = new Buffer(ib);
 
   var usePrivate = (i & 0x80000000) != 0;
 
-  var isPrivate =
-    (this.version == networks['livenet'].hkeyPrivateVersion ||
-    this.version == networks['testnet'].hkeyPrivateVersion);
+  var isPrivate = 
+    (this.version == networks['livenet'].hkeyPrivateVersion  ||
+     this.version == networks['testnet'].hkeyPrivateVersion  );
 
   if (usePrivate && (!this.hasPrivateKey || !isPrivate))
     throw new Error('Cannot do private key derivation without private key');
@@ -4809,24 +4817,18 @@ HierarchicalKey.prototype.deriveChild = function(i) {
     }
 
     var hash = coinUtil.sha512hmac(data, this.chainCode);
-    var il = bignum.fromBuffer(hash.slice(0, 32), {
-      size: 32
-    });
+    var il = bignum.fromBuffer(hash.slice(0, 32), {size: 32});
     var ir = hash.slice(32, 64);
 
     // ki = IL + kpar (mod n).
-    var priv = bignum.fromBuffer(this.eckey.private, {
-      size: 32
-    });
+    var priv = bignum.fromBuffer(this.eckey.private, {size: 32});
     var k = il.add(priv).mod(secp256k1_n);
 
     ret = new HierarchicalKey(null);
     ret.chainCode = ir;
 
     ret.eckey = new Key();
-    ret.eckey.private = k.toBuffer({
-      size: 64
-    });
+    ret.eckey.private = k.toBuffer({size: 32});
     ret.eckey.regenerateSync();
     ret.hasPrivateKey = true;
 
@@ -4852,14 +4854,14 @@ HierarchicalKey.prototype.deriveChild = function(i) {
     ret.chainCode = new Buffer(ir);
 
     var eckey = new Key();
-    eckey.public = newpub;
+    eckey.public = newpub; 
     eckey.compressed = true;
     ret.eckey = eckey;
     ret.hasPrivateKey = false;
   }
 
   ret.childIndex = i;
-  ret.parentFingerprint = this.pubKeyHash.slice(0, 4);
+  ret.parentFingerprint = this.pubKeyHash.slice(0,4);
   ret.version = this.version;
   ret.depth = this.depth + 1;
 
@@ -4868,6 +4870,7 @@ HierarchicalKey.prototype.deriveChild = function(i) {
 
   ret.buildExtendedPublicKey();
   ret.buildExtendedPrivateKey();
+
   return ret;
 }
 
@@ -4883,26 +4886,15 @@ function uint(f, size) {
   return n;
 }
 
-function u8(f) {
-  return uint(f, 1);
-}
-
-function u16(f) {
-  return uint(f, 2);
-}
-
-function u32(f) {
-  return uint(f, 4);
-}
-
-function u64(f) {
-  return uint(f, 8);
-}
+function u8(f)  {return uint(f,1);}
+function u16(f) {return uint(f,2);}
+function u32(f) {return uint(f,4);}
+function u64(f) {return uint(f,8);}
 
 module.exports = require('soop')(HierarchicalKey);
 
 }).call(this,require("buffer").Buffer)
-},{"../networks":"ULNIu2","../util":143,"./Base58":"6VqyzY","./Key":"ALJ4PS","./Point":"6tXgqr","./SecureRandom":"p4SiC2","bignum":58,"buffer":85,"bufferput":"aXRuS6","soop":129}],"CBDCgz":[function(require,module,exports){
+},{"../networks":"ULNIu2","../util":143,"./Base58":"6VqyzY","./Key":"ALJ4PS","./Point":"6tXgqr","./SecureRandom":"p4SiC2","bignum":58,"buffer":85,"soop":129}],"CBDCgz":[function(require,module,exports){
 (function (Buffer){
 'use strict';
 var imports = require('soop').imports();
diff --git a/lib/HierarchicalKey.js b/lib/HierarchicalKey.js
index 24fc8ff..4f45afb 100644
--- a/lib/HierarchicalKey.js
+++ b/lib/HierarchicalKey.js
@@ -6,7 +6,6 @@ var Point = imports.Point || require('./Point');
 var SecureRandom = imports.SecureRandom || require('./SecureRandom');
 var bignum = imports.bignum || require('bignum');
 var networks = require('../networks');
-var BufferPut = require('bufferput');
 
 var secp256k1_n = new bignum('FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFEBAAEDCE6AF48A03BBFD25E8CD0364141', 16);
 var secp256k1_Gx = new bignum('79BE667EF9DCBBAC55A06295CE870B07029BFCDB2DCE28D959F2815B16F81798', 16);
@@ -20,7 +19,8 @@ var HierarchicalKey = function(bytes) {
   if (typeof bytes == 'undefined' || bytes == 'mainnet' || bytes == 'livenet') {
     bytes = 'livenet';
     this.version = networks['livenet'].hkeyPrivateVersion;
-  } else if (bytes == 'testnet') {
+  }
+  else if (bytes == 'testnet') {
     this.version = networks['testnet'].hkeyPrivateVersion;
   }
   if (bytes == 'livenet' || bytes == 'testnet') {
@@ -35,12 +35,12 @@ var HierarchicalKey = function(bytes) {
     this.buildExtendedPrivateKey();
     return;
   }
-
+  
   // decode base58
   if (typeof bytes === 'string') {
     var decoded = base58.decode(bytes);
     if (decoded.length != 82)
-      throw new Error('Not enough data, expected 82 and received ' + decoded.length);
+      throw new Error('Not enough data, expected 82 and received '+decoded.length);
     var checksum = decoded.slice(78, 82);
     bytes = decoded.slice(0, 78);
 
@@ -51,7 +51,7 @@ var HierarchicalKey = function(bytes) {
     }
   }
 
-  if (bytes !== undefined && bytes !== null)
+  if (bytes !== undefined && bytes !== null) 
     this.initFromBytes(bytes);
 }
 
@@ -61,9 +61,9 @@ HierarchicalKey.seed = function(bytes, network) {
 
   if (!Buffer.isBuffer(bytes))
     bytes = new Buffer(bytes, 'hex'); //if not buffer, assume hex
-  if (bytes.length < 128 / 8)
+  if (bytes.length < 128/8)
     return false; //need more entropy
-  if (bytes.length > 512 / 8)
+  if (bytes.length > 512/8)
     return false;
   var hash = coinUtil.sha512hmac(bytes, new Buffer('Bitcoin seed'));
 
@@ -87,23 +87,23 @@ HierarchicalKey.seed = function(bytes, network) {
 
 HierarchicalKey.prototype.initFromBytes = function(bytes) {
   // Both pub and private extended keys are 78 bytes
-  if (bytes.length != 78) throw new Error('not enough data');
+  if(bytes.length != 78) throw new Error('not enough data');
 
-  this.version = u32(bytes.slice(0, 4));
-  this.depth = u8(bytes.slice(4, 5));
+  this.version      = u32(bytes.slice(0, 4));
+  this.depth        = u8(bytes.slice(4, 5));
   this.parentFingerprint = bytes.slice(5, 9);
-  this.childIndex = u32(bytes.slice(9, 13));
-  this.chainCode = bytes.slice(13, 45);
-
+  this.childIndex    = u32(bytes.slice(9, 13));
+  this.chainCode     = bytes.slice(13, 45);
+  
   var keyBytes = bytes.slice(45, 78);
 
-  var isPrivate =
-    (this.version == networks['livenet'].hkeyPrivateVersion ||
-    this.version == networks['testnet'].hkeyPrivateVersion);
+  var isPrivate = 
+    (this.version == networks['livenet'].hkeyPrivateVersion  ||
+     this.version == networks['testnet'].hkeyPrivateVersion  );
 
-  var isPublic =
-    (this.version == networks['livenet'].hkeyPublicVersion ||
-    this.version == networks['testnet'].hkeyPublicVersion);
+  var isPublic = 
+    (this.version == networks['livenet'].hkeyPublicVersion  ||
+     this.version == networks['testnet'].hkeyPublicVersion  );
 
   if (isPrivate && keyBytes[0] == 0) {
     this.eckey = new Key();
@@ -129,30 +129,34 @@ HierarchicalKey.prototype.buildExtendedPublicKey = function() {
   this.extendedPublicKey = new Buffer([]);
 
   var v = null;
-  switch (this.version) {
-    case networks['livenet'].hkeyPublicVersion:
-    case networks['livenet'].hkeyPrivateVersion:
-      v = networks['livenet'].hkeyPublicVersion;
-      break;
-    case networks['testnet'].hkeyPublicVersion:
-    case networks['testnet'].hkeyPrivateVersion:
-      v = networks['testnet'].hkeyPublicVersion;
-      break;
-    default:
-      throw new Error('Unknown version');
+  switch(this.version) {
+  case networks['livenet'].hkeyPublicVersion:
+  case networks['livenet'].hkeyPrivateVersion:
+    v = networks['livenet'].hkeyPublicVersion;
+    break;
+  case networks['testnet'].hkeyPublicVersion:
+  case networks['testnet'].hkeyPrivateVersion:
+    v = networks['testnet'].hkeyPublicVersion;
+    break;
+   default:
+    throw new Error('Unknown version');
   }
 
-  var r = new BufferPut();
-  r = r.word32be(v);
-  r = r.word8(this.depth);
-  r = r.put(this.parentFingerprint);
-  r = r.word32be(this.childIndex);
-  r = r.put(this.chainCode);
-  r = r.put(this.eckey.public);
-
-
-  this.extendedPublicKey = new Buffer(0);
-  this.extendedPublicKey = r.buffer();
+  // Version
+  this.extendedPublicKey = Buffer.concat([
+    new Buffer([v >> 24]),
+    new Buffer([(v >> 16) & 0xff]),
+    new Buffer([(v >> 8) & 0xff]),
+    new Buffer([v & 0xff]),
+    new Buffer([this.depth]),
+    this.parentFingerprint,
+    new Buffer([this.childIndex >>> 24]),
+    new Buffer([(this.childIndex >>> 16) & 0xff]),
+    new Buffer([(this.childIndex >>> 8) & 0xff]),
+    new Buffer([this.childIndex & 0xff]),
+    this.chainCode,
+    this.eckey.public
+  ]);
 }
 
 HierarchicalKey.prototype.extendedPublicKeyString = function(format) {
@@ -174,16 +178,21 @@ HierarchicalKey.prototype.buildExtendedPrivateKey = function() {
 
   var v = this.version;
 
-  var r = new BufferPut();
-  r = r.word32be(v);
-  r = r.word8(this.depth);
-  r = r.put(this.parentFingerprint);
-  r = r.word32be(this.childIndex);
-  r = r.put(this.chainCode);
-  r = r.word8(0);
-  r = r.put(this.eckey.private);
-
-  this.extendedPrivateKey = r.buffer(); 
+  this.extendedPrivateKey = Buffer.concat([
+    new Buffer([v >> 24]),
+    new Buffer([(v >> 16) & 0xff]),
+    new Buffer([(v >> 8) & 0xff]),
+    new Buffer([v & 0xff]),
+    new Buffer([this.depth]),
+    this.parentFingerprint,
+    new Buffer([this.childIndex >>> 24]),
+    new Buffer([(this.childIndex >>> 16) & 0xff]),
+    new Buffer([(this.childIndex >>> 8) & 0xff]),
+    new Buffer([this.childIndex & 0xff]),
+    this.chainCode,
+    new Buffer([0]),
+    this.eckey.private
+  ]);
 }
 
 HierarchicalKey.prototype.extendedPrivateKeyString = function(format) {
@@ -211,17 +220,16 @@ HierarchicalKey.prototype.derive = function(path) {
   for (var i in e) {
     var c = e[i];
 
-    if (i == 0) {
+    if (i == 0 ) {
       if (c != 'm') throw new Error('invalid path');
       continue;
     }
 
-    var usePrivate = (c.length > 1) && (c[c.length - 1] == '\'');
+    var usePrivate = (c.length > 1) && (c[c.length-1] == '\'');
     var childIndex = parseInt(usePrivate ? c.slice(0, c.length - 1) : c) & 0x7fffffff;
 
-    if (usePrivate) {
+    if (usePrivate)
       childIndex += 0x80000000;
-    }
 
     hkey = hkey.deriveChild(childIndex);
   }
@@ -233,15 +241,15 @@ HierarchicalKey.prototype.deriveChild = function(i) {
   var ib = [];
   ib.push((i >> 24) & 0xff);
   ib.push((i >> 16) & 0xff);
-  ib.push((i >> 8) & 0xff);
+  ib.push((i >>  8) & 0xff);
   ib.push(i & 0xff);
   ib = new Buffer(ib);
 
   var usePrivate = (i & 0x80000000) != 0;
 
-  var isPrivate =
-    (this.version == networks['livenet'].hkeyPrivateVersion ||
-    this.version == networks['testnet'].hkeyPrivateVersion);
+  var isPrivate = 
+    (this.version == networks['livenet'].hkeyPrivateVersion  ||
+     this.version == networks['testnet'].hkeyPrivateVersion  );
 
   if (usePrivate && (!this.hasPrivateKey || !isPrivate))
     throw new Error('Cannot do private key derivation without private key');
@@ -257,24 +265,18 @@ HierarchicalKey.prototype.deriveChild = function(i) {
     }
 
     var hash = coinUtil.sha512hmac(data, this.chainCode);
-    var il = bignum.fromBuffer(hash.slice(0, 32), {
-      size: 32
-    });
+    var il = bignum.fromBuffer(hash.slice(0, 32), {size: 32});
     var ir = hash.slice(32, 64);
 
     // ki = IL + kpar (mod n).
-    var priv = bignum.fromBuffer(this.eckey.private, {
-      size: 32
-    });
+    var priv = bignum.fromBuffer(this.eckey.private, {size: 32});
     var k = il.add(priv).mod(secp256k1_n);
 
     ret = new HierarchicalKey(null);
     ret.chainCode = ir;
 
     ret.eckey = new Key();
-    ret.eckey.private = k.toBuffer({
-      size: 64
-    });
+    ret.eckey.private = k.toBuffer({size: 32});
     ret.eckey.regenerateSync();
     ret.hasPrivateKey = true;
 
@@ -300,14 +302,14 @@ HierarchicalKey.prototype.deriveChild = function(i) {
     ret.chainCode = new Buffer(ir);
 
     var eckey = new Key();
-    eckey.public = newpub;
+    eckey.public = newpub; 
     eckey.compressed = true;
     ret.eckey = eckey;
     ret.hasPrivateKey = false;
   }
 
   ret.childIndex = i;
-  ret.parentFingerprint = this.pubKeyHash.slice(0, 4);
+  ret.parentFingerprint = this.pubKeyHash.slice(0,4);
   ret.version = this.version;
   ret.depth = this.depth + 1;
 
@@ -316,6 +318,7 @@ HierarchicalKey.prototype.deriveChild = function(i) {
 
   ret.buildExtendedPublicKey();
   ret.buildExtendedPrivateKey();
+
   return ret;
 }
 
@@ -331,20 +334,9 @@ function uint(f, size) {
   return n;
 }
 
-function u8(f) {
-  return uint(f, 1);
-}
-
-function u16(f) {
-  return uint(f, 2);
-}
-
-function u32(f) {
-  return uint(f, 4);
-}
-
-function u64(f) {
-  return uint(f, 8);
-}
+function u8(f)  {return uint(f,1);}
+function u16(f) {return uint(f,2);}
+function u32(f) {return uint(f,4);}
+function u64(f) {return uint(f,8);}
 
 module.exports = require('soop')(HierarchicalKey);