关键词: 多重数字签名, 伪造攻击, 密码分析, RSA密码体制

Abstract: After analyzing the ID-based digital multi-signature scheme based on RSA (Rivest-Shamir-Adleman) proposed by Zhang et al. in 2008, a complete attack algorithm was proposed. Firstly, Zhang et al.'s scheme and the attack algorithm were introduced, and then two improved schemes against to the security problem of Zhang's scheme were proposed. The random operation of each signer was changed, and part of computation operation was transferred in both of the improved schemes. The results show that the improved schemes are secure without decreasing the efficiency of signing and verifying. Therefore, the improved schemes are more valuable in practical application.

Key words: multi-signature, forgery attack, cryptanalysis, RSA (Rivest-Shamir-Adleman) cryptography