基于ElGamal门限秘密共享的动态多方同时身份认证方案

In most existing authentication schemes users are authenticated by the server one by one which results in lower efficiency of authentication when the number of users is large. Aiming at the drawback, we propose an efficient trusted multi-party authentication scheme based on threshold secret sharing, the discrete logarithm problem and ElGamal cryptosystem. Using (t,n) threshold secret sharing idea, we propose a (t,n) threshold authentication scheme which can not only simultaneously authenticate t users satisfying some specific conditions, but also authenticate new users dynamically by distributing a new authentication key for the new user which was produced by t old users and the new user together. Finally, the security and efficiency of the proposed scheme are analyzed.