Forgery Attacks on “Multisignature Schemes for Authenticating Mobile Code Delegates”

[[abstract]]In 2000, Shieh et al. proposed two novel multisignature schemes (a serial multisignature scheme and a parallel multisignature scheme) that are suitable for authenticating the delegated access, because of its efficiency of computation and communication, message recovery, and no pre-determination of signers and their signing order. However, this article shows that the two schemes are vulnerable to the forgery attacks