摘要
Multi-proxy signature is a scheme that an original signer delegates his or her signing capability to a proxy group. In the scheme, only the cooperation of all proxy signers in the proxy group can create a signature on behalf of the original signer. Jin and Wen firstly defined the formal security model of certificateless multi-proxy signature （CLMPS） and proposed a concrete CLMPS scheme. However, their construction model is inaccurate, the concrete signature scheme has has three problems： the definition of the strengthened security a security flaw, and the proof of the security is imperfect. With further consideration, a remedial strengthened security model is redefined, and an improved scheme is also proposed, which is existentially unforgeable against adaptively chosen-warrant, chosen-message and chosen-identity attacks in the random oracles. In this condition, the computational Diffie-Hellman （CDH） assumption is used to prove full security for our CLMPS scheme.
Multi-proxy signature is a scheme that an original signer delegates his or her signing capability to a proxy group. In the scheme, only the cooperation of all proxy signers in the proxy group can create a signature on behalf of the original signer. Jin and Wen firstly defined the formal security model of certificateless multi-proxy signature （CLMPS） and proposed a concrete CLMPS scheme. However, their construction model is inaccurate, the concrete signature scheme has has three problems： the definition of the strengthened security a security flaw, and the proof of the security is imperfect. With further consideration, a remedial strengthened security model is redefined, and an improved scheme is also proposed, which is existentially unforgeable against adaptively chosen-warrant, chosen-message and chosen-identity attacks in the random oracles. In this condition, the computational Diffie-Hellman （CDH） assumption is used to prove full security for our CLMPS scheme.
基金
supported by the National Natural Science Foundation of China (61170270,61100203,60903152,61003286,61121061)
the Fundamental Research Funds for the Central Universities (BUPT2011YB01,BUPT2011RC0505,2011PTB-00-29,2011RCZJ15,2012RC0612)
