diff --git a/js/models/core/Passphrase.js b/js/models/core/Passphrase.js
index 86f57b1bd..577099c92 100644
--- a/js/models/core/Passphrase.js
+++ b/js/models/core/Passphrase.js
@@ -1,13 +1,34 @@
 'use strict';
 
-var CryptoJS = CryptoJS || require('crypto-js');
+// 65.7% typed (by google's closure-compiler account)
 
+var CryptoJS = CryptoJS || require('crypto-js');
+var preconditions = require('preconditions').instance();
+var _ = require('underscore');
+
+/**
+ * @desc
+ * Class for a Passphrase object, uses PBKDF2 to expand a password
+ *
+ * @constructor
+ * @param {object} config
+ * @param {string=} config.salt - 'mjuBtGybi/4=' by default
+ * @param {number=} config.iterations - 1000 by default
+ */
 function Passphrase(config) {
+  preconditions.checkArgument(!config || !config.salt || _.isString(config.salt));
+  preconditions.checkArgument(!config || !config.iterations || _.isNumber(config.iterations));
   config = config || {};
   this.salt = config.salt || 'mjuBtGybi/4=';
   this.iterations = config.iterations || 1000;
 };
 
+/**
+ * @desc Generate a WordArray expanding a password
+ *
+ * @param {string} password - the password to expand
+ * @returns WordArray 512 bits with the expanded key generated from password
+ */
 Passphrase.prototype.get = function(password) {
   var hash = CryptoJS.SHA256(CryptoJS.SHA256(password));
   var salt = CryptoJS.enc.Base64.parse(this.salt);
@@ -18,20 +39,37 @@ Passphrase.prototype.get = function(password) {
   return key512;
 };
 
+/**
+ * @desc Generate a base64 encoded key
+ *
+ * @param {string} password - the password to expand
+ * @returns {string} 512 bits of a base64 encoded passphrase based on password
+ */
 Passphrase.prototype.getBase64 = function(password) {
   var key512 = this.get(password);
   var keyBase64 = key512.toString(CryptoJS.enc.Base64);
   return keyBase64;
 };
 
+
+/**
+ * @desc Callback for the Passphrase#getBase64Async method
+ * @callback passphraseCallback
+ * @param {string} passphrase 512 bits of a base64 encoded passphrase based on password
+ */
+
+/**
+ * @desc Generate a base64 encoded key, without blocking
+ *
+ * @param {string} password - the password to expand
+ * @param {passphraseCallback} cb
+ */
 Passphrase.prototype.getBase64Async = function(password, cb) {
   var self = this;
   setTimeout(function() {
     var ret = self.getBase64(password);
     return cb(ret);
-  }, 10);
+  }, 0);
 };
 
-
-
 module.exports = Passphrase;