Patent ID: 7752444
Filing Date: 2010-07-06
Classification: H04L

Abstract:
1. A method of hiding an initiator's identity (ID) in a shared key authentication protocol, the method comprising the steps of: applying, by an initiator, a function which cannot be readily inverted to the initiator's ID to produce a Hint of the ID, the Hint of the ID enabling a receiver to identify a subset of possible shared keys from a plurality of known shared keys, the subset containing fewer than all of the known shared keys; transmitting the Hint of the ID and a Message Authentication Code (MAC) created from a message using a shared key associated with the initiator; receiving the Hint of the ID and the MAC by the receiver; using, by the receiver, the Hint of the ID to determine the subset of possible shared keys; creating, by the receiver, MACs of the message using shared keys within the subset of possible shared keys to look for a shared key that will produce a MAC of the message that matches the MAC of the message transmitted by the initiator; and upon producing a MAC of the message from one of the shared keys that matches the MAC of the message transmitted by the initiator, determining therefrom the identity of the initiator.