Research On Attribute-based Sigma-Protocol And Attribute-Based Identification

Attribute-based cryptography can provide fine-grained access control and good privacy,while the application scope of identity-based cryptography is limited.In order to meet the large-scale demand,it is extremely important to add the concept of attributes into the scheme,so it has become a hot research field of cryptography.The bottleneck problem and the risk of the whole system collapse exist in the centralization,and the application scenario is limited.On this basis,it is particularly important to introduce the concept of decentralization.Decentralization can overcome the bottleneck problem of a single attribute authority and the security problem of the system,so the application scenarios are wider.Sigma-protocol is a 3-move interactive zero-knowledge proof protocol,which can prove the possession of certain knowledge by zero-knowledge proof,and has many important applications in the field of cryptography.Identification can prove one's identity to others under the condition of hiding one's key or personal identification number,so it has been studied by many researchers.Firstly,attribute-based cryptography and sigma-protocol are combined,and the formal definition and security definition of attribute-based sigma-protocol are given.Combined with standard sigma-protocol,trapdoor samplable relation and smooth secret sharing scheme,the first general construction method decentralized attribute-based sigma-protocol is obtained,and the security of the construction scheme is proved.In order to reflect the construction process more intuitively,a concrete example is given.Secondly,we combine the attribute-based cryptography,identification and sigma-protocol,and get the scheme of sigma-type decentralized attribute-based identification.This thesis studies the relationship between sigma-type attribute-based identification and sigma-type identity-based identification and proposes a generic construction of sigma-type decentralized attribute-based identification.The generic construction uses the smooth secret sharing scheme to transform the sigma-type identity-based identification into the decentralized attribute-based identification,and the security of the construction scheme is proved.A concrete example of the general construction is given,and the efficiency of the proposed scheme is compared with that of the existing schemes.Finally,this thesis also presents the specific applications of the decentralized attribute-based sigma-protocol and the sigma-type decentralized attribute-based identification respectively.The first is to obtain the corresponding decentralized attribute-based signature scheme by using the Fiat-Shamir transformation of the above two schemes.The second can be applied to the decentralized attribute-based two-tier signature.Fiat-Shamir transformation is also used to convert the obtained decentralized attribute-based sigma-protocol into the decentralized attribute-based two-tier signature.The results show that the proposed scheme is superior to the existing schemes in terms of data lengths and computation costs.