Cryptanalysis of Dynamic Group Signature Scheme
Lei Hu · Jisuanji yingyong yanjiu · 2007
Group signature allows an arbitrary member in a group can sign a signature on behalf of the group whilst the identity of the member remains anonymous.When a dispute investigation happens,the identity of the signer can be traced by the group manager.Member deletion is one of the kittlest problems in group signature schemes.An Efficient and Secure Dynamic Group Signature Scheme,He Yefeng and Zhang Jianzhong gave a method based on ELGamal encryption and signature of knowledge to solve the problem,in 2005.But we point out that in their scheme,the member who had been deleted from group can still give out a group signature that can pass the verification successfully,so there has some weakness in the security of their scheme.