Cryptanalysis of Two Multi-signature Schemes
XU Guang-bao · Information Security and Communications Privacy · 2010
Based on in-depth study of the two multi-signature schemes,a forgery attack is proposed.In the first scheme,anyone of the signers could generate a valid multi-signature without others' participation,this shows that the scheme is not secure.In the second scheme,the designated combiner could acquire the secret key of each member and easily forge a valid threshold signature,this shows the scheme is not secure too.The reasons for successful attack are analyzed,thus providing an effective reference for the design of new secure schemes.