Cryptanalysis and Improvement of an Identity-based Signature Scheme
Deng Xiao-hong · Jisuanji gongcheng · 2012
This paper concludes that the efficient identity-based signature scheme proposed by Li Jiguo et al is insecure,and gives an attack method,which shows that any attacker can forge a valid signature on any message with respect to any identity.Therefore,Li Jiguo’s scheme does not satisfy existential unforgeability.By making a component of a signature as user’s public key,an improved scheme is proposed,which does not reduce the efficiency of Li Jiguo et al’s scheme while satisfying the existential unforgeability.