The deficiencies of the first threshold Guilbu-Quisquater signature schemepresented by Li-San Liu, Cheng-Kang Chu and Wen-Guey Tzeng arc analysiscd at first, and then a newthreshold Guillou-Quisquater signature scheme...The deficiencies of the first threshold Guilbu-Quisquater signature schemepresented by Li-San Liu, Cheng-Kang Chu and Wen-Guey Tzeng arc analysiscd at first, and then a newthreshold Guillou-Quisquater signature scheme is presented. The new scheme isunforgeable and robustagainst any adaptive adversary if the base Guillou-Quisquater signature scheme is unforgeable underthe chosen message attack and computing the discrete logarithm modulo a prime is hard This schemecan also achieve optimal resilience. However, the new scheme does not need the assumption that N isthe product of two safe primes. The basie signature scheme underlying the new scheme is exactlyGuillou-Quisqualtr signature scheme, and the additional strong computation assumption introduced bythe first threshold Guillou-Quisquater scheme is weaken.展开更多
The drawback of the first asynchronous proactive RSA scheme presented by Zhou in 2001, is that the security definition and security proof do not follow the approach of provable security. This paper presented a provabl...The drawback of the first asynchronous proactive RSA scheme presented by Zhou in 2001, is that the security definition and security proof do not follow the approach of provable security. This paper presented a provably secure asynchronous proactive RSA scheme, which includes three protocols: initial key distribution protocol, signature generation protocol and share refreshing protocol. Taken these protocols together, a complete provably secure proactive RSA scheme was obtained. And the efficiency of the scheme is approximate to that of the scheme of Zhou.展开更多
This paper proposes a(t,n)-threshold verifiable secret sharing scheme with changeable parameters based on a trapdoor one-way function.This scheme consists of a generation phase,a distribution phase,an encoding phase a...This paper proposes a(t,n)-threshold verifiable secret sharing scheme with changeable parameters based on a trapdoor one-way function.This scheme consists of a generation phase,a distribution phase,an encoding phase and a reconstruction phase.The generation and distribution phases are,respectively,based on Shamir’s and Feldman’s approaches,while the encoding phase is based on a novel trapdoor one-way function.In the reconstruction phase,the shares and reconstructed secret are validated using a cryptographic hash function.In comparison with existing schemes,the proposed scheme leaks no direct information about the secret from public information.Furthermore,unlike some existing schemes,the generation and distribution phases of the proposed scheme are both independent of the secret.This feature leads to a number of advantages over existing approaches such as the dealer’s ability to perform the following modifications without updating the shares(i)modify the secret and(ii)adjust the threshold parameters of the scheme.Furthermore,each participant receives a single share,and designated participants can be given the privilege of choosing their own shares for reconstructing a secret S.Moreover,the proposed scheme possesses a high level of security which is inherited from the schemes of Shamir and Feldman,in addition to the trapdoor one-way function and the employed cryptographic hash function.展开更多
文摘The deficiencies of the first threshold Guilbu-Quisquater signature schemepresented by Li-San Liu, Cheng-Kang Chu and Wen-Guey Tzeng arc analysiscd at first, and then a newthreshold Guillou-Quisquater signature scheme is presented. The new scheme isunforgeable and robustagainst any adaptive adversary if the base Guillou-Quisquater signature scheme is unforgeable underthe chosen message attack and computing the discrete logarithm modulo a prime is hard This schemecan also achieve optimal resilience. However, the new scheme does not need the assumption that N isthe product of two safe primes. The basie signature scheme underlying the new scheme is exactlyGuillou-Quisqualtr signature scheme, and the additional strong computation assumption introduced bythe first threshold Guillou-Quisquater scheme is weaken.
文摘The drawback of the first asynchronous proactive RSA scheme presented by Zhou in 2001, is that the security definition and security proof do not follow the approach of provable security. This paper presented a provably secure asynchronous proactive RSA scheme, which includes three protocols: initial key distribution protocol, signature generation protocol and share refreshing protocol. Taken these protocols together, a complete provably secure proactive RSA scheme was obtained. And the efficiency of the scheme is approximate to that of the scheme of Zhou.
文摘This paper proposes a(t,n)-threshold verifiable secret sharing scheme with changeable parameters based on a trapdoor one-way function.This scheme consists of a generation phase,a distribution phase,an encoding phase and a reconstruction phase.The generation and distribution phases are,respectively,based on Shamir’s and Feldman’s approaches,while the encoding phase is based on a novel trapdoor one-way function.In the reconstruction phase,the shares and reconstructed secret are validated using a cryptographic hash function.In comparison with existing schemes,the proposed scheme leaks no direct information about the secret from public information.Furthermore,unlike some existing schemes,the generation and distribution phases of the proposed scheme are both independent of the secret.This feature leads to a number of advantages over existing approaches such as the dealer’s ability to perform the following modifications without updating the shares(i)modify the secret and(ii)adjust the threshold parameters of the scheme.Furthermore,each participant receives a single share,and designated participants can be given the privilege of choosing their own shares for reconstructing a secret S.Moreover,the proposed scheme possesses a high level of security which is inherited from the schemes of Shamir and Feldman,in addition to the trapdoor one-way function and the employed cryptographic hash function.
