无可信中心的(t,n)门限签名方案

在基于离散对数的安全机制的前提下讨论了(t，n)门限群签名方案．目前流行的门限签名方案一般可分为需要可信中心和不需要可信中心两类．由于在许多特定的应用环境下，一个可被所有成员信任的可信中心并不存在，所以不需要可信中心的门限群签名方案就显得很有吸引力．但已有的方案中使用了秘密共享技术，超过门限值的小组成员利用他们所掌握的秘密份额就能够恢复某个成员的私钥．为了解决这个问题，在新的方案中，利用联合秘密共享技术(joint secret sharing)解决了传统的秘密共享技术造成的成员的私钥泄露问题．

(t,n) Threshold Signature Scheme Without a Trusted Party

This paper discusses the (t,n) threshold signature scheme based on the difficulty of solving the discrete logarithm problem. All up-to-date solutions for threshold signature can be classified into the two categories:(1) solutions with the assistance of a trusted party (2) solutions without the assistance of a trusted party. Generally speaking, as an authority which can be trusted by all members doesn't exist, a threshold signature scheme without a trusted party appears more attractive. However, Secret Sharing technique used in previous schemes may cause some colluding members of the group to obtain secret keys of others. In order to solve the problem, authors present a new scheme by use of Joint Secret Sharing technique to protect secret keys of group members.