Date Added: Sep 2009
The braid groups have attracted much attention as a new platform of constructing cryptosystems. This paper firstly analyzes the security vulnerabilities of existing proxy signature schemes over braid groups and presents feasible attacks. Then a new proxy signature scheme is proposed based on the difficulty of the conjugacy search problem and the multiple conjugacy search problem. Security analysis shows that the proposed scheme satisfies the security requirements of proxy signature. This paper analyzes the security weaknesses of the existing proxy signature schemes over braid groups and proposes a new scheme which satisfies the security requirements. The rest of this paper is organized as follows. The second section introduces the basics of braid groups and proxy signatures.