A Key Authentication Scheme for Non-repudiation

Abstract

In 1996, Horng and Yang had proposed a key authentication scheme that requires no authorities (Computer Communication 19(1996)848-850). However, it is vulnerable to the guessing attack. An intruder can try out a password and forge the public key. To amend this problem, an improved authentication scheme intended to prevent the guessing attack and the forging problem was proposed by Zhan et al. (Computer Communication 22(1999)739-741). However, their scheme did not achieve non-repudiation of public key. In order to achieve non-repudiation of public key, a key authentication scheme for non-repudiation is proposed in this paper. Our scheme will show that the attacker can neither repudiate public key nor forge a public key. The security of our scheme is based on the difficulty of solving the discrete logarithm problem.