Patent ID: 8908866

Claim:
A method comprising: receiving a challenge at a radio frequency identification (RFID) tag from an RFID tag reader; initializing the RFID tag based upon a first public key of a first key pair, a second public key of a second key pair, and a tag ID n received from the RFID tag reader; calculating S=f (s, O E ), U=f (u, O O ), B=E (n, k E ), G=f (A, k O ), where A is a function of the challenge and a private key of the RFID tag, s and u are random numbers, k E and ko are functions of the first public key and the second public key, respectively, and O E and O O are originators, provided by the reader; and returning S, U, B, and G from the RFID tag to the reader, the returned data being unique for each response even when responding to an identical challenge.