Moving 'n' to Policy.

nkms/policy/models.py

@@ -86,10 +86,6 @@ class PolicyGroup(object):
         self.uri = uri
         self.treasure_map = TreasureMap()
 
-    @property
-    def n(self):
-        return len(self.policies)
-
     @staticmethod
     def hash(message):
         return keccak_digest(message)
@@ -218,6 +214,10 @@ class Policy(object):
 
         self._encrypted_challenge_pack = encrypted_challenge_pack
 
+    @property
+    def n(self):
+        return len(self.kfrags)
+
     @property
     def id(self):
         if self._id: