Cryptanalysis of an efficient group signature schemen

Abstract

The security flaws of the group signature proposed by Zhang Jianhong and etc.was analyzed.It pointed out that the group signature was not untraceable for the revocation center could not open a valid group signature.A coalition attack that the manager and the revocation center could conspire to generate valid group signatures and impose them on an arbitrary member of the group was presented.The security analysis show that the scheme is insecure.

Keywords

• cryptography;group signature;cryptanalysis;coalition attack