Research And Design On Identity-Based Linkable Ring Signature On Lattice

In recent years,the blockchain is booming,and the privacy security of both parties in blockchain has caused widespread concern from all fields of society.The privacy of both parties being protected only through pseudo-anonymity cannot satisfy complete privacy protection demand.Therefore,how to better ensure the collaboration and value transfer between untrusted individuals on the blockchain,and to transmit sensitive data in security is the problem that needed to be solved quickly.Linkable ring signature(LRS)is a special ring signature.It can ensure that two or more ring signatures signed with the same private key cannot pass the verification of link algorithm for different messages and public key sets,which can meet privacy protection requirement of blockchain applications and prevent users from double spending.Although gradual progress has been made for LRS in the last few years,problems such as the following still exist.First,the LRS based on classical number theory problems in public key infrastructure(PKI)system cannot effectively resist the attack of quantum algorithm,and has complicated certificate management problems.Second,most existing LRS schemes on lattice have the disadvantages of excessive time and storage overhead and need to be further optimized.Finally,identity-based linkable ring signatures(IBLRS)on lattice cannot enjoy fine-grained access control of users and realize the user anonymity better.To solve them,this paper carries out the study the LRS scheme over lattice,the main contents are as follows.(1)To make the LRS based on the classical number theory problem effectively resist the attack of quantum algorithm,and avoid complicated certificate management problems,this paper introduces identity-based cryptography into the LRS scheme,and an IBLRS over lattice is proposed based on techniques of preimage sampling and rejection sampling.It is proved that this scheme meets unconditional anonymity,unforgeability and linkability in the ROM.Compared with the existing schemes,the efficiency of key generation and signature verification is improved.Experimental results show that the efficiency of the key generation and signature verification is improved roughly by 64.53%and 38.21% at 80-bits security,respectively.(2)Aiming at the problems that the signature calculation efficiency of most existing LRS schemes on lattice is low and the communication and storage overhead is large,an IBLRS scheme over NTRU lattice is constructed by employing the technologies of trapdoor generation and rejection sampling,the security of this scheme relies on the problem of NTRU-SIS.Compared with the existing schemes,this scheme has a shorter size of public/private keys,and when the number of ring members is small(such as N ≤8),this scheme also has a smaller signature size.The computational efficiency of signature has also been further improved since it only involves multiplication in the polynomial ring and modular operations of small integers.The experimental result indicated that the time for the signature generation and verification of this scheme decreases roughly by 44.951% and 33.503% at 80-bits security,respectively.(3)To make up for the defects of IBLRS on lattice,which cannot enjoy fine-grained access control of users and cannot realize the user anonymity better,an attribute-based linkable ring signature(ABLRS)scheme over lattice is given by employing the technologies of GPV trapdoor generation and rejection sampling.Compared with the IBRS,the user identity of the proposed scheme is represented by a combination of attributes,and then the attribute set is used to manage the user’s signature authority,which has stronger anonymity.Furthermore,the proposed scheme can detect whether the user has completed two or more signatures with the identical private key.The results indicate that the signature generation and verification efficiency of this scheme improves roughly by 58.82% and 36.91% at security level λ =100 compared with other existing similar schemes,respectively.There are 11 figures,25 tables and 85 references.