diff --git a/authentic2_idp_ltpa/utils.py b/authentic2_idp_ltpa/utils.py
index 77b6ede..9d53b1a 100644
--- a/authentic2_idp_ltpa/utils.py
+++ b/authentic2_idp_ltpa/utils.py
@@ -55,7 +55,7 @@ def parse_token(token, secret=None, user_charset='utf8'):
                 digest, computed_digest)
     return user, creation, expire
 
-if __name__ == '__main__':
+def main():
     import argparse
     import datetime
 
@@ -71,10 +71,15 @@ if __name__ == '__main__':
     parser_generate.add_argument('user', help='user\'s username')
 
     # create the parser for the "b" command
-    parser_parse = subparsers.add_parser('parse', help='b help')
+    parser_parse = subparsers.add_parser('parse', help='parse an LtpaToken')
     parser_parse.set_defaults(command='parse')
     parser_parse.add_argument('token', help='the LTPA cookie content')
 
+    parser_decryptkey = subparsers.add_parser('decryptkey', help='decrypt an exported shared key for LtpaToken')
+    parser_decryptkey.set_defaults(command='decryptkey')
+    parser_parse.add_argument('file', help='file containing an exported shared key')
+    parser_parse.add_argument('password', help='password for the encryption')
+
     args = parser.parse_args()
     if args.secret:
         if args.secret.startswith('hex:'):
@@ -97,3 +102,15 @@ if __name__ == '__main__':
         print 'User:', user
         print 'Creation timestamp:', from_timestamp(creation)
         print 'Expire timestamp:', from_timestamp(expire)
+    elif args.command == 'decryptkey':
+        from pyDes import des, ECB, PAD_PKCS5
+
+        content = file(args.file).read()
+        key = hashlib.sha1(args.password).digest() + '\x00' * 4
+
+        data = "Please encrypt my data"
+        k = des(key, ECB, padmode=PAD_PKCS5)
+        print 'hex:' + k.decrypt(content).encode('hex')
+
+if __name__ == '__main__':
+    main()
diff --git a/setup.py b/setup.py
index 22122c4..9d37a28 100755
--- a/setup.py
+++ b/setup.py
@@ -10,7 +10,7 @@ setup(name='authentic2-idp-ltpa',
         author_email="info@entrouvert.com",
         packages=find_packages(os.path.dirname(__file__) or '.'),
         install_requires=[
-            'djangorestframework',
+            'pyDes',
         ],
         entry_points={
             'authentic2.plugin': [