Patent ID: 7567672
Filing Date: 2009-07-28
Classification: H04L

Abstract:
1. A cryptographic communication system comprising: a store that stores a plurality of elements a, b, c, d of a finite group as a public key and a parameter “x” as a private key, wherein “x” is equal to a discrete logarithm of “b” to base “a”; means for generating random values β, γ and δ; a prover connected to a communication channel and accessible to said public key, said private key, and said random values, for calculating e=a a verifier, connected through said channel to said prover, for receiving the transmitted e, g and h, and determining whether said prover is capable of establishing said relations by using the public key and the received e, g, h, and determining whether there is a mismatch between g and h, whereby said prover establishes a proof that the parameter x is not equal to discrete logarithm of “d” to base “c” only if said verifier determines that said relations are established and detects said mismatch.