In order to achieve more secure group signature schemes, the security flaws of a group signature proposed by Lin and Dou recently were analyzed. It was found that the group signature does not satisfy the secure property of resisting forgery attack. Without using any secret identification or secret key, anyone can forge a valid signature only through selecting some random parameters and changing the calculation procedures. The possibility of forging the group scheme was analyzed, and a forgery attack example was designed to prove that Lin Dou’s group signature scheme is insecure.
