Research On Group Signatures And Their Applications

Digital signature scheme was proposed by Whitfiele Diffie and Matin Hellmanthe since 1976,it has been an essential tool to construct secure cryptographic algorithms.A secure digital signature scheme can achieve authentication,integrity and non-repudiation.Besides the features of ordinary digital signatures,group signatures allow a member to anonymously sign on behalf of the group,a special kind of digital signature mechanism,and can achieve traceability when necessary.As a result,group signatures have more practical applications than ordinary digital signatures,particularly in the area of privacy protection.Despite of a decade of extensive research,the most group signature schemes require expensive computing,or generate long size of signature,or are infeasible in membership revocation.Therefore,it remains a significant research work to design secure,efficient and flexible group signature schemes.Additionally,with the rapid development of quantum computers,these group signature schemes,which depend on traditional hardness problems,will suffer a serious security threat.Designing secure cryptographic algorithms against quantum computer attacks is a hot topic.Lattice-based cryptographic,conjectured to resist against quantum computers,has become one of the most trendy research direction.Along with other primitives,lattice-based group signatures have received noticeable attention.Lastly,with computational power improves,the low efficiency of group signature scheme is becoming less important.The applications of group signature schemes have attracted cryptographic researchers' widely attention because their advantages.Therefore,it is urgent for us to investigate new efficient group signatures and its applications.Specifically,the main research results are as follows:1.Research on a revocable dynamic group signature scheme from traditional hard problem.(1)Based on the extended q-SDH prblem,we construct a zero-knowledge proof protocol,and prove that the protocol is complete,simulatable and extractable.(2)We propose an efficient dynamic group signature scheme that supports dynamic members join and revocation,and can achieve non-frameability.(3)We prove that our proposed group signatures achieves fully-anonymity,fully-traceability and nonframeability in the random oracle model.(4)Last,we analyze the performance of our scheme in terms of signature size and computation overhead,and provide simulation results.This analysis includes a comparison between the four best-known group signature schemes.2.Research on group signatures from lattice assumptions.(1)If quantum computers are ever developed,the traditional group signature schemes will be insecure.Lattice-based group signatures are considered as the most promising alternative in quantum computer age.We investigate the existing lattice-based group signatures.None of them allow members to join and leave the group at arbitrary time.(2)Based on lattice-based identification scheme,we propose a new lattice-based group signature scheme.Our scheme supports dynamic members join and revocation.(3)In the random oracle model,we prove that our proposed group signature scheme can achieve full-anonymity,full-traceability and non-frameability.Additionally,in terms of the security features,functionality and efficiency,we demonstrate a comparison between the existing best-known lattice-based group schemes.3.Research on access control based on group signatures in cloud service.(1)The disappear of trusted domain and relationship that cannot trust their cloud computing provider bring some new challenges to access control.Many existing access control models can not adapt the needs of cloud computing environment.(2)We build an access control framework,which can manage multi-group and validate the group certificates of users.Furthermore,we construct the security model of this framework based on the construction of group signature.(3)Based on our dynamic group signatures,we propose a new access control scheme for cloud computing environment.In the random oracle model,we prove that our scheme can achieve anonymous authentication and accountability.Additionally,we analyze the performance of our scheme in terms of enrollment,authentication and user revocation.4.Research on lattice-based compact e-cash scheme.(1)Compact e-cash schemes are efficiency soultion to implement withdraw protocol and achieve anonymity of users.Therefore,it has attracted researchers' extensive attention.Nevertheless,the security of existing e-cash schemes are based on traditional hardness problems.(2)Integrating lattice-based digital signature scheme with zero-knowledge protocol,we propose a off-line compact e-cash scheme,which is constructed based on lattice.Thus,it is the first compact e-cash scheme against quantum computer attacks.(3)In the random oracle model,we prove that our scheme can achieve balance,anonymity of users,identification of double-spenders and exculpability.