Comments on an efficient group signature scheme
评一种高效的群签名

Group signature schemes are extended from ordinary digital signatures motivated by a variety of applications.Zhang et al proposed an efficient group signature scheme which was claimed to be more efficient than the well known ACJT scheme,because expensive signature of knowledge,a component in a majority of group signature schemes,was avoided in generating the group signature.In this paper,we point out that Zhang(et al's) scheme actually adopted signature of knowledge,and it is completely insecure because of the inappropriate design.