Patent ID: 8627080

Claim:
A method for mutual authentication between a first entity and a second entity, comprising: obtaining first dynamic data; retrieving at least a portion of key data from a data storage; calculating a first authentication code based on said first dynamic data and said at least a portion of key data; transmitting at least a portion of said first dynamic data and said first authentication code to said second entity; modifying said first dynamic data to form second dynamic data; calculating a second authentication code based on said second dynamic data and said at least a portion of key data; modifying at least one of said first dynamic data and said second dynamic data to form third dynamic data; calculating a third authentication code based on said third dynamic data and said at least a portion of key data; generating a decryption key based at least in part on said third authentication code; receiving authentication data from said second entity; decrypting at least a portion of said authentication data based on said decryption key to form decrypted authentication data; comparing at least a portion of said decrypted authentication data to said second authentication code; and verifying the identity of said second entity based at least in part on said comparing step.