Abstract：Identity-based signatures are the groundwork of many cryptographic protocols. This paper analyzed GU KE et al.'s (GU KE, JIA WEIJIA, JIANG CHUNLIANG. Efficient and secure identity-based signature scheme. Journal of Software,2011,22(6):1350-1360) efficient identity-based signature scheme. Two equivalent signature generating algorithms were proposed and it was pointed out that Gu et al.'s scheme could not satisfy the basic security properties. In other words, any attacker could use the equivalent secret key and signature generating algorithms proposed in this paper to forge a valid secret key of a user and a valid signature on any message with respect to any identity in their scheme. Furthermore, the reason that the scheme is insecure was also analyzed and it was pointed out that designing a more efficient identity-based signature scheme than the classical one is almost impossible.
2013, Vol. 33 
