Cryptanalysis of One Fair E-cash System  

作　　者：刘丽华 沈灏 

机构地区：[1]Dept.of Mathematics,Shanghai Jiaotong Univ.,Shanghai 200240, China,Dept. of Information and Computation Science, Shanghai Maritime University,Shanghai 200135 [2]Dept.of Mathematics,Shanghai Jiaotong Univ., Shanghai 200240, China

出　　处：《Journal of Shanghai Jiaotong university(Science)》2006年第3期389-393,共5页上海交通大学学报（英文版）

摘　　要：The security of Canard-Traore fair e-cash system scheme was believed to depend on the strong-RSA assumption and the Decision Diffie-Hellman assumption in groups of unknown order. But it is not the case. The cryptanalysis on Canard-Traore fair e-cash system was presented. An algorithm was designed to show that Canard-Traore fair e-cash system is insecure: It is forgeability. Further, two drawbacks on Canard-Traore fair e-cash system scheme were pointed out. One is that those integer intervals for si（i=1,…,9） are unappropriate. The other is that the datum s3 in signature data is redundant. Moreover, a minute description of the technique to shun the challenge in the scheme was presented. The technique is helpful for designing new group signature schemes in the future.The security of Canard-Traore fair e-cash system scheme was believed to depend on the strong-RSA assumption and the Decision Diffie-Hellman assumption in groups of unknown order. But it is not the case. The cryptanalysis on Canard Traore fair e-cash system was presented. An algorithm was designed to show that Canard- Traore fair e-cash system is insecure： It is forgeability. Further, two drawbacks on Canard-Traore fair e-cash system scheme were pointed out. One is that those integer intervals for si（i=1,……,9） are unappropriate. The other is that the datum s3 in signature data is redundant. Moreover, a minute description of the technique to shun the challenge in the scheme was presented. The technique is helpful for designing new group signature schemes in the future.

关 键 词：CRYPTANALYSIS group signature fair e-cash system FORGEABILITY 

分 类 号：O29[理学—应用数学] TB11[理学—数学]