diff --git a/oauth3.issuer.mock.js b/oauth3.issuer.mock.js
index ea72fa7..d64122f 100644
--- a/oauth3.issuer.mock.js
+++ b/oauth3.issuer.mock.js
@@ -3,12 +3,12 @@
 
   var OAUTH3 = exports.OAUTH3 = exports.OAUTH3 || require('./oauth3.core.js').OAUTH3;
 
-  OAUTH3.utils.bufferToBinaryString = function (buf) {
+  OAUTH3.utils.bufferToBinStr = function (buf) {
     return Array.prototype.map.call(new Uint8Array(buf), function(ch) {
       return String.fromCharCode(ch);
     }).join('');
   };
-  OAUTH3.utils.binaryStringToBuffer = function (str) {
+  OAUTH3.utils.binStrToBuffer = function (str) {
     var buf;
 
     if ('undefined' !== typeof Uint8Array) {
@@ -23,6 +23,13 @@
     return buf;
   };
 
+  OAUTH3._base64.urlSafeToBuffer = function (str) {
+    return OAUTH3.utils.binStrToBuffer(OAUTH3._base64.decodeUrlSafe(str));
+  };
+  OAUTH3._base64.bufferToUrlSafe = function (buf) {
+    return OAUTH3._base64.encodeUrlSafe(OAUTH3.utils.bufferToBinStr(buf));
+  };
+
   OAUTH3.crypto = {};
   OAUTH3.crypto.fingerprintJWK = function (jwk) {
     var keys;
@@ -44,15 +51,15 @@
     }
 
     var jwkStr = '{' + keys.map(function (name) { return name+':'+jwk[name]; }).join(',') + '}';
-    return window.crypto.subtle.digest({name: 'SHA-256'}, OAUTH3.utils.binaryStringToBuffer(jwkStr))
-    .then(OAUTH3.utils.bufferToBinaryString).then(OAUTH3._base64.btoa);
+    return window.crypto.subtle.digest({name: 'SHA-256'}, OAUTH3.utils.binStrToBuffer(jwkStr))
+    .then(OAUTH3._base64.bufferToUrlSafe);
   };
 
   OAUTH3.crypto._createKey = function (ppid) {
     var kekPromise, ecdsaPromise, secretPromise;
     var salt = window.crypto.getRandomValues(new Uint8Array(16));
 
-    kekPromise = window.crypto.subtle.importKey('raw', OAUTH3.utils.binaryStringToBuffer(ppid), {name: 'PBKDF2'}, false, ['deriveKey'])
+    kekPromise = window.crypto.subtle.importKey('raw', OAUTH3.utils.binStrToBuffer(ppid), {name: 'PBKDF2'}, false, ['deriveKey'])
     .then(function (key) {
       var opts = {name: 'PBKDF2', salt: salt, iterations: 8192, hash: {name: 'SHA-256'}};
       return window.crypto.subtle.deriveKey(opts, key, {name: 'AES-GCM', length: 128}, false, ['encrypt']);
@@ -85,8 +92,8 @@
     });
 
     return OAUTH3.PromiseA.all([kekPromise, ecdsaPromise, secretPromise]).then(function (keys) {
-      var ecdsaJwk  = OAUTH3.utils.binaryStringToBuffer(JSON.stringify(keys[1].privateKey));
-      var secretJwk = OAUTH3.utils.binaryStringToBuffer(JSON.stringify(keys[2]));
+      var ecdsaJwk  = OAUTH3.utils.binStrToBuffer(JSON.stringify(keys[1].privateKey));
+      var secretJwk = OAUTH3.utils.binStrToBuffer(JSON.stringify(keys[2]));
       var ecdsaIv  = window.crypto.getRandomValues(new Uint8Array(12));
       var secretIv = window.crypto.getRandomValues(new Uint8Array(12));
 
@@ -97,22 +104,22 @@
       .then(function (encrypted) {
         return {
           publicKey:  keys[1].publicKey
-        , privateKey: OAUTH3._base64.btoa(OAUTH3.utils.bufferToBinaryString(encrypted[0]))
-        , userSecret: OAUTH3._base64.btoa(OAUTH3.utils.bufferToBinaryString(encrypted[1]))
-        , salt:       OAUTH3._base64.btoa(OAUTH3.utils.bufferToBinaryString(salt))
-        , ecdsaIv:    OAUTH3._base64.btoa(OAUTH3.utils.bufferToBinaryString(ecdsaIv))
-        , secretIv:   OAUTH3._base64.btoa(OAUTH3.utils.bufferToBinaryString(secretIv))
+        , privateKey: OAUTH3._base64.bufferToUrlSafe(encrypted[0])
+        , userSecret: OAUTH3._base64.bufferToUrlSafe(encrypted[1])
+        , salt:       OAUTH3._base64.bufferToUrlSafe(salt)
+        , ecdsaIv:    OAUTH3._base64.bufferToUrlSafe(ecdsaIv)
+        , secretIv:   OAUTH3._base64.bufferToUrlSafe(secretIv)
         };
       });
     });
   };
 
   OAUTH3.crypto._decryptKey = function (ppid, storedObj) {
-    var salt   = OAUTH3.utils.binaryStringToBuffer(OAUTH3._base64.atob(storedObj.salt));
-    var encJwk = OAUTH3.utils.binaryStringToBuffer(OAUTH3._base64.atob(storedObj.privateKey));
-    var iv     = OAUTH3.utils.binaryStringToBuffer(OAUTH3._base64.atob(storedObj.ecdsaIv));
+    var salt   = OAUTH3._base64.urlSafeToBuffer(storedObj.salt);
+    var encJwk = OAUTH3._base64.urlSafeToBuffer(storedObj.privateKey);
+    var iv     = OAUTH3._base64.urlSafeToBuffer(storedObj.ecdsaIv);
 
-    return window.crypto.subtle.importKey('raw', OAUTH3.utils.binaryStringToBuffer(ppid), {name: 'PBKDF2'}, false, ['deriveKey'])
+    return window.crypto.subtle.importKey('raw', OAUTH3.utils.binStrToBuffer(ppid), {name: 'PBKDF2'}, false, ['deriveKey'])
     .then(function (key) {
       var opts = {name: 'PBKDF2', salt: salt, iterations: 8192, hash: {name: 'SHA-256'}};
       return window.crypto.subtle.deriveKey(opts, key, {name: 'AES-GCM', length: 128}, false, ['decrypt']);
@@ -120,7 +127,7 @@
     .then(function (key) {
       return window.crypto.subtle.decrypt({name: 'AES-GCM', iv: iv}, key, encJwk);
     })
-    .then(OAUTH3.utils.bufferToBinaryString)
+    .then(OAUTH3.utils.bufferToBinStr)
     .then(JSON.parse)
     .then(function (jwk) {
       return window.crypto.subtle.importKey('jwk', jwk, {name: 'ECDSA', namedCurve: jwk.crv}, false, ['sign'])
@@ -133,9 +140,9 @@
   };
 
   OAUTH3.crypto._getKey = function (ppid) {
-    return window.crypto.subtle.digest({name: 'SHA-256'}, OAUTH3.utils.binaryStringToBuffer(ppid))
+    return window.crypto.subtle.digest({name: 'SHA-256'}, OAUTH3.utils.binStrToBuffer(ppid))
     .then(function (hash) {
-      var name = 'kek-' + OAUTH3._base64.btoa(OAUTH3.utils.bufferToBinaryString(hash));
+      var name = 'kek-' + OAUTH3._base64.bufferToUrlSafe(hash);
       var promise;
 
       if (window.localStorage.getItem(name) === null) {
@@ -161,9 +168,9 @@
       , OAUTH3._base64.encodeUrlSafe(JSON.stringify(payload, null))
       ].join('.');
 
-      return window.crypto.subtle.sign({name: 'ECDSA', hash: {name: 'SHA-256'}}, key, OAUTH3.utils.binaryStringToBuffer(input))
+      return window.crypto.subtle.sign({name: 'ECDSA', hash: {name: 'SHA-256'}}, key, OAUTH3.utils.binStrToBuffer(input))
       .then(function (signature) {
-        return input + '.' + OAUTH3._base64.encodeUrlSafe(OAUTH3.utils.bufferToBinaryString(signature));
+        return input + '.' + OAUTH3._base64.bufferToUrlSafe(signature);
       });
     });
   };