diff --git a/package.json b/package.json
index 3b5cf18..7d766ac 100644
--- a/package.json
+++ b/package.json
@@ -75,7 +75,6 @@
     "bigi": "1.1.0",
     "bs58": "1.2.1",
     "bs58check": "1.0.1",
-    "crypto-js": "3.1.2-3",
     "crypto-browserify": "3.0.0",
     "ecurve": "1.0.0"
   }
diff --git a/src/convert.js b/src/convert.js
deleted file mode 100644
index 8548866..0000000
--- a/src/convert.js
+++ /dev/null
@@ -1,32 +0,0 @@
-var assert = require('assert')
-var Crypto = require('crypto-js')
-var WordArray = Crypto.lib.WordArray
-
-function bufferToWordArray(buffer) {
-  assert(Buffer.isBuffer(buffer), 'Expected Buffer, got', buffer)
-
-  var words = []
-  for (var i = 0, b = 0; i < buffer.length; i++, b += 8) {
-    words[b >>> 5] |= buffer[i] << (24 - b % 32)
-  }
-
-  return new WordArray.init(words, buffer.length)
-}
-
-function wordArrayToBuffer(wordArray) {
-  assert(Array.isArray(wordArray.words), 'Expected WordArray, got' + wordArray)
-
-  var words = wordArray.words
-  var buffer = new Buffer(words.length * 4)
-
-  words.forEach(function(value, i) {
-    buffer.writeInt32BE(value & -1, i * 4)
-  })
-
-  return buffer
-}
-
-module.exports = {
-  bufferToWordArray: bufferToWordArray,
-  wordArrayToBuffer: wordArrayToBuffer
-}
diff --git a/src/crypto.js b/src/crypto.js
index 1c8423b..890bf0a 100644
--- a/src/crypto.js
+++ b/src/crypto.js
@@ -1,8 +1,4 @@
-// Crypto, crypto, where art thou crypto
-var assert = require('assert')
-var CryptoJS = require('crypto-js')
 var crypto = require('crypto')
-var convert = require('./convert')
 
 function hash160(buffer) {
   return ripemd160(sha256(buffer))
@@ -29,16 +25,8 @@ function HmacSHA256(buffer, secret) {
   return crypto.createHmac('sha256', secret).update(buffer).digest()
 }
 
-function HmacSHA512(data, secret) {
-  assert(Buffer.isBuffer(data), 'Expected Buffer for data, got ' + data)
-  assert(Buffer.isBuffer(secret), 'Expected Buffer for secret, got ' + secret)
-
-  var dataWords = convert.bufferToWordArray(data)
-  var secretWords = convert.bufferToWordArray(secret)
-
-  var hash = CryptoJS.HmacSHA512(dataWords, secretWords)
-
-  return convert.wordArrayToBuffer(hash)
+function HmacSHA512(buffer, secret) {
+  return crypto.createHmac('sha512', secret).update(buffer).digest()
 }
 
 module.exports = {
diff --git a/src/index.js b/src/index.js
index 73f3c1e..0ab57e2 100644
--- a/src/index.js
+++ b/src/index.js
@@ -1,7 +1,6 @@
 module.exports = {
   Address: require('./address'),
   bufferutils: require('./bufferutils'),
-  convert: require('./convert'),
   crypto: require('./crypto'),
   ecdsa: require('./ecdsa'),
   ECKey: require('./eckey'),
diff --git a/test/convert.js b/test/convert.js
deleted file mode 100644
index 0b06e44..0000000
--- a/test/convert.js
+++ /dev/null
@@ -1,27 +0,0 @@
-var assert = require('assert')
-var convert = require('../src/convert')
-
-var fixtures = require('./fixtures/convert')
-
-describe('convert', function() {
-  describe('bufferToWordArray', function() {
-    fixtures.valid.forEach(function(f) {
-      it('converts ' + f.hex + ' correctly', function() {
-        var buffer = new Buffer(f.hex, 'hex')
-        var result = convert.bufferToWordArray(buffer)
-
-        assert.deepEqual(result, f.wordArray)
-      })
-    })
-  })
-
-  describe('wordArrayToBuffer', function() {
-    fixtures.valid.forEach(function(f) {
-      it('converts to ' + f.hex + ' correctly', function() {
-        var resultHex = convert.wordArrayToBuffer(f.wordArray).toString('hex')
-
-        assert.deepEqual(resultHex, f.hex)
-      })
-    })
-  })
-})
diff --git a/test/fixtures/convert.json b/test/fixtures/convert.json
deleted file mode 100644
index b759004..0000000
--- a/test/fixtures/convert.json
+++ /dev/null
@@ -1,25 +0,0 @@
-{
-  "valid": [
-    {
-      "hex": "0000000000000000000000000000000000000000",
-      "wordArray": {
-        "words": [0, 0, 0, 0, 0],
-        "sigBytes": 20
-      }
-    },
-    {
-      "hex": "62e907b15cbf27d5425399ebf6f0fb50ebb88f18",
-      "wordArray": {
-        "words": [1659439025, 1556031445, 1112775147, -151979184, -340226280],
-        "sigBytes": 20
-      }
-    },
-    {
-      "hex": "ffffffffffffffffffffffffffffffffffffffff",
-      "wordArray": {
-        "words": [-1, -1, -1, -1, -1],
-        "sigBytes": 20
-      }
-    }
-  ]
-}