diff --git a/oauth3.core.js b/oauth3.core.js
index 37d7c63..02085a1 100644
--- a/oauth3.core.js
+++ b/oauth3.core.js
@@ -207,12 +207,12 @@
     }
   , jwt: {
       // decode only (no verification)
-      decode: function (str) {
+      decode: function (token, opts) {
 
         // 'abc.qrs.xyz'
         // [ 'abc', 'qrs', 'xyz' ]
         // {}
-        var parts = str.split(/\./g);
+        var parts = token.split(/\./g);
         var err;
         if (parts.length !== 3) {
           err = new Error("Invalid JWT: required 3 '.' separated components not "+parts.length);
@@ -220,14 +220,55 @@
           throw err;
         }
 
-        return JSON.parse(OAUTH3._base64.decodeUrlSafe(parts[1]));
+        if (!opts || !opts.complete) {
+          return JSON.parse(OAUTH3._base64.decodeUrlSafe(parts[1]));
+        }
+        return {
+          header:  JSON.parse(OAUTH3._base64.decodeUrlSafe(parts[0]))
+        , payload: JSON.parse(OAUTH3._base64.decodeUrlSafe(parts[1]))
+        };
       }
-    , verify: function (jwk, token) {
+    , verify: function (token, jwk) {
+        if (!OAUTH3.crypto) {
+          return OAUTH3.PromiseA.reject(new Error("OAuth3 crypto library unavailable"));
+        }
+        jwk = jwk.publicKey || jwk;
+
         var parts = token.split(/\./g);
         var data = OAUTH3._binStr.binStrToBuffer(parts.slice(0, 2).join('.'));
         var signature = OAUTH3._base64.urlSafeToBuffer(parts[2]);
 
-        return OAUTH3.crypto.core.verify(jwk, data, signature);
+        return OAUTH3.crypto.core.verify(jwk, data, signature).then(function () {
+          return OAUTH3.jwt.decode(token);
+        });
+      }
+    , sign: function (payload, jwk) {
+        if (!OAUTH3.crypto) {
+          return OAUTH3.PromiseA.reject(new Error("OAuth3 crypto library unavailable"));
+        }
+        jwk = jwk.privateKey || jwk;
+
+        var prom;
+        if (jwk.kid) {
+          prom = OAUTH3.PromiseA.resolve(jwk.kid);
+        } else {
+          prom = OAUTH3.crypto.thumbprintJwk(jwk);
+        }
+
+        return prom.then(function (kid) {
+          // Currently the crypto part of the OAuth3 library only supports ES256
+          var header = {type: 'JWT', alg: 'ES256', kid: kid};
+          var input = [
+            OAUTH3._base64.encodeUrlSafe(JSON.stringify(header, null))
+          , OAUTH3._base64.encodeUrlSafe(JSON.stringify(payload, null))
+          ].join('.');
+
+          return OAUTH3.crypto.core.sign(jwk, OAUTH3._binStr.binStrToBuffer(input))
+            .then(OAUTH3._base64.bufferToUrlSafe)
+            .then(function (signature) {
+              return input + '.' + signature;
+            });
+        });
       }
     , freshness: function (tokenMeta, staletime, now) {
         // If the token doesn't expire then it's always fresh.
diff --git a/oauth3.crypto.js b/oauth3.crypto.js
index 67c27ff..85479fc 100644
--- a/oauth3.crypto.js
+++ b/oauth3.crypto.js
@@ -1,5 +1,5 @@
 ;(function (exports) {
-'use strict';
+  'use strict';
 
   var OAUTH3 = exports.OAUTH3 = exports.OAUTH3 || require('./oauth3.core.js').OAUTH3;
 
@@ -82,6 +82,7 @@
     };
 
     function checkWebCrypto() {
+      /* global OAUTH3_crypto_fallback */
       var loadFallback = function() {
         var prom;
         loadFallback = function () { return prom; };
@@ -102,11 +103,10 @@
         return prom;
       };
       function checkException(name, func) {
-        new OAUTH3.PromiseA(function (resolve) { resolve(func()); })
+        OAUTH3.PromiseA.resolve().then(func)
           .then(function () {
             OAUTH3.crypto.core[name] = webCrypto[name];
-          })
-          .catch(function (err) {
+          }, function (err) {
             console.warn('error with WebCrypto', name, '- using fallback', err);
             loadFallback().then(function () {
               OAUTH3.crypto.core[name] = OAUTH3_crypto_fallback[name];
@@ -195,101 +195,61 @@
       .then(OAUTH3._base64.bufferToUrlSafe);
   };
 
-  OAUTH3.crypto._createKey = function (ppid) {
-    var saltProm = OAUTH3.crypto.core.randomBytes(16);
-    var kekProm = saltProm.then(function (salt) {
-      return OAUTH3.crypto.core.pbkdf2(ppid, salt);
-    });
-
-    var ecdsaProm = OAUTH3.crypto.core.genEcdsaKeyPair()
-    .then(function (keyPair) {
+  OAUTH3.crypto.createKeyPair = function () {
+    // TODO: maybe support other types of key pairs, not just ECDSA P-256
+    return OAUTH3.crypto.core.genEcdsaKeyPair().then(function (keyPair) {
       return OAUTH3.crypto.thumbprintJwk(keyPair.publicKey).then(function (kid) {
         keyPair.privateKey.alg = keyPair.publicKey.alg = 'ES256';
         keyPair.privateKey.kid = keyPair.publicKey.kid = kid;
         return keyPair;
       });
     });
+  };
+
+  OAUTH3.crypto.encryptKeyPair = function (keyPair, password) {
+    var saltProm = OAUTH3.crypto.core.randomBytes(16);
+    var kekProm = saltProm.then(function (salt) {
+      return OAUTH3.crypto.core.pbkdf2(password, salt);
+    });
 
     return OAUTH3.PromiseA.all([
       kekProm
-    , ecdsaProm
     , saltProm
-    , OAUTH3.crypto.core.randomBytes(16)
     , OAUTH3.crypto.core.randomBytes(12)
-    , OAUTH3.crypto.core.randomBytes(12)
-    ]).then(function (results) {
+  , ]).then(function (results) {
       var kek        = results[0];
-      var keyPair    = results[1];
-      var salt       = results[2];
-      var userSecret = results[3];
-      var ecdsaIv    = results[4];
-      var secretIv   = results[5];
+      var salt       = results[1];
+      var ecdsaIv    = results[2];
 
-      return OAUTH3.PromiseA.all([
-        OAUTH3.crypto.core.encrypt(kek, ecdsaIv, OAUTH3._binStr.binStrToBuffer(JSON.stringify(keyPair.privateKey)))
-      , OAUTH3.crypto.core.encrypt(kek, secretIv, userSecret)
-      ])
-      .then(function (encrypted) {
+      var privKeyBuf = OAUTH3._binStr.binStrToBuffer(JSON.stringify(keyPair.privateKey));
+      return OAUTH3.crypto.core.encrypt(kek, ecdsaIv, privKeyBuf).then(function (encrypted) {
         return {
           publicKey:  keyPair.publicKey
-        , privateKey: OAUTH3._base64.bufferToUrlSafe(encrypted[0])
-        , userSecret: OAUTH3._base64.bufferToUrlSafe(encrypted[1])
+        , privateKey: OAUTH3._base64.bufferToUrlSafe(encrypted)
         , salt:       OAUTH3._base64.bufferToUrlSafe(salt)
         , ecdsaIv:    OAUTH3._base64.bufferToUrlSafe(ecdsaIv)
-        , secretIv:   OAUTH3._base64.bufferToUrlSafe(secretIv)
-        };
+      , };
       });
     });
   };
 
-  OAUTH3.crypto._decryptKey = function (ppid, storedObj) {
+  OAUTH3.crypto.decryptKeyPair = function (storedObj, password) {
     var salt   = OAUTH3._base64.urlSafeToBuffer(storedObj.salt);
     var encJwk = OAUTH3._base64.urlSafeToBuffer(storedObj.privateKey);
     var iv     = OAUTH3._base64.urlSafeToBuffer(storedObj.ecdsaIv);
 
-    return OAUTH3.crypto.core.pbkdf2(ppid, salt)
+    return OAUTH3.crypto.core.pbkdf2(password, salt)
       .then(function (key) {
         return OAUTH3.crypto.core.decrypt(key, iv, encJwk);
       })
       .then(OAUTH3._binStr.bufferToBinStr)
-      .then(JSON.parse);
-  };
-
-  OAUTH3.crypto._getKey = function (ppid) {
-    return OAUTH3.crypto.core.sha256(OAUTH3._binStr.binStrToBuffer(ppid))
-    .then(function (hash) {
-      var name = 'kek-' + OAUTH3._base64.bufferToUrlSafe(hash);
-      var promise;
-
-      if (window.localStorage.getItem(name) === null) {
-        promise = OAUTH3.crypto._createKey(ppid).then(function (key) {
-          window.localStorage.setItem(name, JSON.stringify(key));
-          return key;
-        });
-      } else {
-        promise = OAUTH3.PromiseA.resolve(JSON.parse(window.localStorage.getItem(name)));
-      }
-
-      return promise.then(function (storedObj) {
-        return OAUTH3.crypto._decryptKey(ppid, storedObj);
+      .then(JSON.parse)
+      .then(function (privateKey) {
+        return {
+          privateKey: privateKey
+        , publicKey:  storedObj.publicKey
+      , };
       });
-    });
-  };
-
-  OAUTH3.crypto._signPayload = function (payload) {
-    return OAUTH3.crypto._getKey('some PPID').then(function (key) {
-      var header = {type: 'JWT', alg: key.alg, kid: key.kid};
-      var input = [
-        OAUTH3._base64.encodeUrlSafe(JSON.stringify(header, null))
-      , OAUTH3._base64.encodeUrlSafe(JSON.stringify(payload, null))
-      ].join('.');
-
-      return OAUTH3.crypto.core.sign(key, OAUTH3._binStr.binStrToBuffer(input))
-        .then(OAUTH3._base64.bufferToUrlSafe)
-        .then(function (signature) {
-          return input + '.' + signature;
-        });
-    });
   };
 
 }('undefined' !== typeof exports ? exports : window));