Cryptanalysis of Two Multisignature Schemes with Distinguished Signing Authorities
Eun‐Jun Yoon, Kee-Young Yoo · 2006
In 2005, Huang and Chang proposed two multisignature schemes with distinguished signing authorities. The two schemes are based on a RSA cryptosystem and a discrete logarithm with composite modulus. One scheme is suitable for sequential architecture and the other for broadcasting. However, the current paper demonstrates an attack on Huang-Chang?s two multisignature schemes in which attacker can derive a user?s secret key and forge multisignatures schemes in arbitrary messages.