对一种改进的ElGamal数字签名方案的攻击与改进

ATTACK AND IMPROVEMENT ON AN IMPROVED ELGAMAL DIGITAL SIGNATURE SCHEME

针对无Hash函数的ElGamal离散对数数字签名问题,对其各类改进方案进行分析研究,对最新的改进方案进行伪造签名攻击。给出4种伪造签名方法,证明其不具有安全性。针对其方案的缺点提出一个新的改进方案。证明了其正确性和安全性,可防止各种伪造攻击和同态攻击。

Aiming at the problem of ElGamal discrete logarithmic digital signature without Hash function, we analyzed and studied various improved schemes. In this paper, an improved ElGamal digital signature scheme was analytical attacked. We gave four forgery signature schemes and proved to be insecure. In view of the shortcomings of improved ElGamal digital signature scheme, we proposed a new improved scheme we proved its correctness and security, and it could prevent various forgery attacks and homomorphism attacks.