Patent ID: 8631491

Claim:
In a communication network including a sending node operably linked to a receiving node, the sending node operable to send data packets to the receiving node, a method comprising the sending node, in association with a packet index i: generating a random number r i ; retrieving a code sequence (h* i−1 ); generating a hash value h i based on the random number r i and the code sequence (h* i−1 ); formulating a packet with index i including h i , r i and data i ; and sending the packet i to the receiving node; wherein h i and r i are retrievable by the receiving node for use in detecting replay attacks, the receiving node maintaining a code sequence (h* j ), generating a hash value (h j+1 ) based on the random number r i and the code sequence (h* j ), and declaring a replay attack if h i does not equal h j+1 .