Cryptanalysis of Threshold Signature Scheme for Group Communication
Wang Qing-ju · Journal of Huaqiao University · 2008
Recently,Chang proposed a(t,n) threshold signature with(k,l) threshold-shared verification to be used in agroup-oriented cryptosystem without a shared distribution center(SDC).In their scheme,any t participants can represent a group(signing group) to sign a message,and any k participants can represent another group(verifying group) to verify the signature.In this paper,we will argue that Chang′s scheme is vulnerable to the impersonation attack,and violates the basic definition requirement of(t,n) threshold signature with(k,l) threshold-shared verification.