(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.