diff --git a/hmac_key.py b/hmac_key.py
new file mode 100644
index 0000000..98d1b51
--- /dev/null
+++ b/hmac_key.py
@@ -0,0 +1,40 @@
+# -*- Mode:python; c-file-style:"gnu"; indent-tabs-mode:nil -*- */
+#
+# Copyright (C) 2014 Regents of the University of California.
+# Author: Weiwei Liu <summerwing10@gmail.com> 
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU Lesser General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+# A copy of the GNU General Public License is in the file COPYING.
+
+class HMACKey(object):
+    """
+    HMACKey implements the  HMAC symmetric key
+    """
+    def __init__(self, sequence, counter, key, name = None):
+        self._name = name
+        self._sequence = sequence
+        self._counter = counter
+        self._key = key
+
+    def getName(self):
+        return self._name
+  
+    def getSequence(self):
+        return self._sequence
+ 
+    def getCounter(self):
+        return self._counter
+   
+    def getKey(self):
+        return self._key
+