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...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.展开更多
Leakage of the private key has become a serious problem of menacing the cryptosystem security. To reduce the underlying danger induced by private key leakage, Dodis et al.(2003) proposed the first key-insulated signat...Leakage of the private key has become a serious problem of menacing the cryptosystem security. To reduce the underlying danger induced by private key leakage, Dodis et al.(2003) proposed the first key-insulated signature scheme. To handle issues concerning the private key leakage in certificateless signature schemes, we devise the first certificateless key-insulated signature scheme. Our scheme applies the key-insulated mechanism to certificateless cryptography, one with neither certificate nor key escrow. We incorporate Waters (2005)’s signature scheme, Paterson and Schuldt (2006)’s identity-based signature scheme, and Liu et al.(2007)’s certificateless signature scheme to obtain a certificateless key-insulated signature scheme. Our scheme has two desirable properties. First, its security can be proved under the non-pairing-based generalized bilinear Diffie-Hellman (NGBDH) conjecture, without utilizing the random oracle model; second, it solves the key escrow problem in identity-based key-insulated signatures.展开更多
基金Supported by the National Natural Science Foundation of China under Grant No.60673070the Natural Science Foundation of Jiangsu Province of China under Grant No.BK2006217~~
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)
文摘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Project (Nos 60573032, 60773092, 60842002, 60873229, and 90604036) supported by the National Natural Science Foundation of China
文摘Leakage of the private key has become a serious problem of menacing the cryptosystem security. To reduce the underlying danger induced by private key leakage, Dodis et al.(2003) proposed the first key-insulated signature scheme. To handle issues concerning the private key leakage in certificateless signature schemes, we devise the first certificateless key-insulated signature scheme. Our scheme applies the key-insulated mechanism to certificateless cryptography, one with neither certificate nor key escrow. We incorporate Waters (2005)’s signature scheme, Paterson and Schuldt (2006)’s identity-based signature scheme, and Liu et al.(2007)’s certificateless signature scheme to obtain a certificateless key-insulated signature scheme. Our scheme has two desirable properties. First, its security can be proved under the non-pairing-based generalized bilinear Diffie-Hellman (NGBDH) conjecture, without utilizing the random oracle model; second, it solves the key escrow problem in identity-based key-insulated signatures.
