Public key cryptosystems are proposed to protect users'security of communications over the Internet from malicious attacks. Hence, to verify the validity of the public key of the legal user has become an important issue. In 2003, Lee et al. proposed a public key authentication scheme based on the discrete logarithm problem. Unfortunately, Peinado soon pointed out that Lee et al.'s scheme has a serious security problem, which the private key of the user can be compromised easily from the public key certificate of the user. Besides, Peinado also proposed an improvement to fix the security flaw of Lee et al.'s scheme. However, we find that the improvement and Lee et al.'s scheme are still suffered from the security weakness which the private key of the user can be compromised easily. In this article, we not only show the common security flaw of these schemes but also present an improvement on these public key authentication schemes based on the discrete logarithm problem.
Relation:
Journal of Discrete Mathematical Sciences & Cryptography 10(3):351-358
