diff --git a/karma.conf.js b/karma.conf.js
index 9a6ca1a..c2c9d5c 100644
--- a/karma.conf.js
+++ b/karma.conf.js
@@ -3,7 +3,7 @@
 module.exports = function(config) {
 
   config.set({
-    browsers: ['Firefox'],
+    browsers: ['PhantomJS'],
     frameworks: ['mocha'],
     singleRun: true,
     files: [
@@ -11,7 +11,7 @@ module.exports = function(config) {
     ],
     plugins: [
       'karma-mocha',
-      'karma-firefox-launcher'
+      'karma-phantomjs-launcher'
     ]
   });
 
diff --git a/lib/bitauth-browserify.js b/lib/bitauth-browserify.js
index e3f8d7a..4895a02 100644
--- a/lib/bitauth-browserify.js
+++ b/lib/bitauth-browserify.js
@@ -1,7 +1,7 @@
 'use strict';
 
-var elliptic = require('elliptic');
-var ecdsa = new elliptic.ec(elliptic.curves.secp256k1);
+var EC = require('elliptic').ec;
+var ecdsa = new EC('secp256k1');
 
 var BitAuth = require('./bitauth-common');
 
@@ -19,7 +19,7 @@ BitAuth._getPublicKeyFromPrivateKey = function(privkey) {
   } else {
     privKeyString = privkey;
   }
-  var keys = ecdsa.keyPair(privkey, 'hex');
+  var keys = ecdsa.keyFromPrivate(privKeyString, 'hex');
 
   // compressed public key
   var pubKey = keys.getPublic();
@@ -36,13 +36,14 @@ BitAuth._getPublicKeyFromPrivateKey = function(privkey) {
 };
 
 BitAuth._sign = function(hashBuffer, privkey) {
-  var signature = ecdsa.sign(hashBuffer.toString('hex'), privkey);
+  var keys = ecdsa.keyFromPrivate(privkey, 'hex');
+  var signature = keys.sign(hashBuffer.toString('hex'));
   var hexsignature = signature.toDER('hex');
   return hexsignature;
 };
 
 BitAuth._verifySignature = function(hashBuffer, signatureBuffer, pubkey) {
-  return ecdsa.verify(hashBuffer.toString('hex'), signatureBuffer, pubkey);
+  return ecdsa.verify(hashBuffer.toString('hex'), signatureBuffer, pubkey, 'hex');
 };
 
 module.exports = BitAuth;
diff --git a/lib/bitauth-common.js b/lib/bitauth-common.js
index 195ab2e..dbc756f 100644
--- a/lib/bitauth-common.js
+++ b/lib/bitauth-common.js
@@ -104,13 +104,16 @@ BitAuth.sign = function(data, privkey) {
  */
 BitAuth.verifySignature = function(data, pubkey, hexsignature, callback) {
   var dataBuffer;
+
   if (!Buffer.isBuffer(data)) {
     dataBuffer = new Buffer(data, 'utf8');
   } else {
     dataBuffer = data;
   }
+
   var hashBuffer = crypto.createHash('sha256').update(dataBuffer).digest();
   var signatureBuffer;
+
   if (!Buffer.isBuffer(hexsignature)) {
     signatureBuffer = new Buffer(hexsignature, 'hex');
   } else {
diff --git a/package.json b/package.json
index cb9fca3..b7c9189 100644
--- a/package.json
+++ b/package.json
@@ -31,7 +31,8 @@
   "version": "0.3.2",
   "dependencies": {
     "bs58": "^2.0.0",
-    "elliptic": "=1.0.0",
+    "elliptic": "=6.4.0",
+    "karma-chrome-launcher": "^2.2.0",
     "secp256k1": "=1.1.5"
   },
   "devDependencies": {
@@ -41,16 +42,16 @@
     "bundle-collapser": "^1.2.1",
     "chai": "=1.9.1",
     "express": "^4.13.3",
-    "gulp": "^3.8.10",
+    "gulp": "^3.9.1",
     "gulp-bump": "^0.1.11",
-    "gulp-git": "^0.5.5",
+    "gulp-git": "^2.5.1",
     "gulp-mocha": "^2.0.0",
     "gulp-shell": "^0.2.10",
-    "karma": "^0.13.9",
-    "karma-firefox-launcher": "^0.1.4",
-    "karma-mocha": "^0.1.9",
-    "mocha": "~1.20.1",
-    "request": "^2.65.0",
+    "karma": "^2.0.0",
+    "karma-mocha": "^1.3.0",
+    "karma-phantomjs-launcher": "^1.0.4",
+    "mocha": "^5.0.0",
+    "request": "^2.83.0",
     "run-sequence": "^1.0.2",
     "uglify-js": "~2.4.14"
   },