Patent ID: 7653197

Claim:
A method of secret key agreement between a first and a second correspondent, the method comprising the acts of: (a) said first correspondent receiving a response A, from a source P, said first correspondent comprising a first arithmetic logic unit of a processor; (b) said second correspondent receiving a response B from said source P, said second correspondent comprising a second arithmetic logic unit of a processor; (c) said first correspondent generating (d−1) parity symbols as an output of a codeword W whose input includes said response A and a secret key K selected by said first correspondent; (d) said first correspondent transmitting said (d−1) parity symbols over a public communication channel to said second correspondent; and (e) said second correspondent generating a codeword W′ whose input includes said (d−1) parity symbols and said response B to determine said secret key K; wherein the secret key K may be determined from said (d−1) parity symbols and said response B by satisfying an inequality, dH ( A,B )<=( d− 1 −k )/2 where dH(A,B) is a Hamming distance between symbol sequences A and B, d is a minimum distance, and k is a number of symbols in the secret key K.