diff --git a/keystoneclient/middleware/auth_token.py b/keystoneclient/middleware/auth_token.py
index e2628b624..e606b9c5a 100644
--- a/keystoneclient/middleware/auth_token.py
+++ b/keystoneclient/middleware/auth_token.py
@@ -769,6 +769,8 @@ class AuthProtocol(object):
         :no longer raises ServiceError since it no longer makes RPC
 
         """
+        token_id = None
+
         try:
             token_id = cms.cms_hash_token(user_token)
             cached = self._cache_get(token_id)
@@ -784,12 +786,13 @@ class AuthProtocol(object):
             return data
         except NetworkError as e:
             self.LOG.debug('Token validation failure.', exc_info=True)
-            self.LOG.warn("Authorization failed for token %s", user_token)
+            self.LOG.warn("Authorization failed for token %s", token_id)
             raise InvalidUserToken('Token authorization failed')
         except Exception as e:
             self.LOG.debug('Token validation failure.', exc_info=True)
-            self._cache_store_invalid(user_token)
-            self.LOG.warn("Authorization failed for token %s", user_token)
+            if token_id:
+                self._cache_store_invalid(token_id)
+            self.LOG.warn("Authorization failed for token %s", token_id)
             raise InvalidUserToken('Token authorization failed')
 
     def _token_is_v2(self, token_info):
@@ -930,20 +933,20 @@ class AuthProtocol(object):
         env_key = self._header_to_env_var(key)
         return env.get(env_key, default)
 
-    def _cache_get(self, token, ignore_expires=False):
+    def _cache_get(self, token_id, ignore_expires=False):
         """Return token information from cache.
 
         If token is invalid raise InvalidUserToken
         return token only if fresh (not expired).
         """
 
-        if self._cache and token:
+        if self._cache and token_id:
             if self._memcache_security_strategy is None:
-                key = CACHE_KEY_TEMPLATE % token
+                key = CACHE_KEY_TEMPLATE % token_id
                 serialized = self._cache.get(key)
             else:
                 keys = memcache_crypt.derive_keys(
-                    token,
+                    token_id,
                     self._memcache_secret_key,
                     self._memcache_security_strategy)
                 cache_key = CACHE_KEY_TEMPLATE % (
@@ -968,17 +971,18 @@ class AuthProtocol(object):
             # a collision with json.loads(serialized) == None.
             cached = json.loads(serialized)
             if cached == 'invalid':
-                self.LOG.debug('Cached Token %s is marked unauthorized', token)
+                self.LOG.debug('Cached Token %s is marked unauthorized',
+                               token_id)
                 raise InvalidUserToken('Token authorization failed')
 
             data, expires = cached
             if ignore_expires or time.time() < float(expires):
-                self.LOG.debug('Returning cached token %s', token)
+                self.LOG.debug('Returning cached token %s', token_id)
                 return data
             else:
-                self.LOG.debug('Cached Token %s seems expired', token)
+                self.LOG.debug('Cached Token %s seems expired', token_id)
 
-    def _cache_store(self, token, data):
+    def _cache_store(self, token_id, data):
         """Store value into memcache.
 
         data may be the string 'invalid' or a tuple like (data, expires)
@@ -986,11 +990,11 @@ class AuthProtocol(object):
         """
         serialized_data = json.dumps(data)
         if self._memcache_security_strategy is None:
-            cache_key = CACHE_KEY_TEMPLATE % token
+            cache_key = CACHE_KEY_TEMPLATE % token_id
             data_to_store = serialized_data
         else:
             keys = memcache_crypt.derive_keys(
-                token,
+                token_id,
                 self._memcache_secret_key,
                 self._memcache_security_strategy)
             cache_key = CACHE_KEY_TEMPLATE % memcache_crypt.get_cache_key(keys)
@@ -1025,7 +1029,7 @@ class AuthProtocol(object):
             raise InvalidUserToken('Token authorization failed')
         return expires
 
-    def _cache_put(self, token, data, expires):
+    def _cache_put(self, token_id, data, expires):
         """Put token data into the cache.
 
         Stores the parsed expire date in cache allowing
@@ -1033,15 +1037,15 @@ class AuthProtocol(object):
 
         """
         if self._cache:
-                self.LOG.debug('Storing %s token in memcache', token)
-                self._cache_store(token, (data, expires))
+                self.LOG.debug('Storing %s token in memcache', token_id)
+                self._cache_store(token_id, (data, expires))
 
-    def _cache_store_invalid(self, token):
+    def _cache_store_invalid(self, token_id):
         """Store invalid token in cache."""
         if self._cache:
             self.LOG.debug(
-                'Marking token %s as unauthorized in memcache', token)
-            self._cache_store(token, 'invalid')
+                'Marking token %s as unauthorized in memcache', token_id)
+            self._cache_store(token_id, 'invalid')
 
     def cert_file_missing(self, proc_output, file_name):
         return (file_name in proc_output and not os.path.exists(file_name))
diff --git a/tests/test_auth_token_middleware.py b/tests/test_auth_token_middleware.py
index 439522599..8ec13fe98 100644
--- a/tests/test_auth_token_middleware.py
+++ b/tests/test_auth_token_middleware.py
@@ -1076,9 +1076,17 @@ class AuthTokenMiddlewareTest(BaseAuthTokenMiddlewareTest):
         self.middleware(req.environ, self.start_fake_response)
         self.assertEqual(self.response_status, 401)
 
-    def test_memcache_set_invalid(self):
+    def test_memcache_set_invalid_uuid(self):
         req = webob.Request.blank('/')
-        token = 'invalid-token'
+        token = uuid.uuid4().hex
+        req.headers['X-Auth-Token'] = token
+        self.middleware(req.environ, self.start_fake_response)
+        self.assertRaises(auth_token.InvalidUserToken,
+                          self._get_cached_token, token)
+
+    def test_memcache_set_invalid_signed(self):
+        req = webob.Request.blank('/')
+        token = self.token_dict['signed_token_scoped_expired']
         req.headers['X-Auth-Token'] = token
         self.middleware(req.environ, self.start_fake_response)
         self.assertRaises(auth_token.InvalidUserToken,