摘要
Digital signature,as an important cryptographic primitive,has been widely used in many application scenarios,such as e-commerce,authentication,cloud computing,and so on.Certificateless Public Key Cryptography(PKC)can get rid of the certificate management problem in the traditional Public Key Infrastructure(PKI)and eliminate the key-escrow problem in the identity-based PKC.Lately,a new Certificateless Signature(CLS)scheme has been proposed by Kyung-Ah Shim(IEEE SYSTEMS JOURNAL,2018,13(2)),which claimed to achieve provable security in the standard model.Unfortunately,we present a concrete attack to demonstrate that the scheme cannot defend against the Type I adversary.In this type of attack,the adversary can replace the public key of the signer,and then he plays the role of the signer to forge a legal certificateless signature on any message.Furthermore,we give an improved CLS scheme to resist such an attack.In terms of the efficiency and the signature length,the improved CLS is preferable to the original scheme and some recently proposed CLS schemes in the case of precomputation.
基金
The work was partially supported by the National Natural Science Foundation of China under grant Nos.61872060 and 61772292
the National Key R&D Program of China under grant No.2017YFB0802000
Key Laboratory of Financial Mathematics of Fujian Province University(Putian University)under grant Nos.JR201806 and JR201901
by the Natural Science Foundation of Fujian Province under grant Nos.2019J01752 and 2020J01905
by the Program for Innovative Research Team in Science and Technology in Fujian Province University under grant No.2018-049
by the Educational Research Projects of Young and Middle-aged Teachers in Fujian Education Department(JAT200514).
