Identity-based cryptography (IBC) can be applied to scenarios that involve a large number of public keys in each execution. In this paper, we propose an efficient identity-based ring signature scheme on lattices with signature size logarithmic to the cardinality of the ring. To this end, we first construct an efficient identity-based ring identification scheme by combining preimage sampling algorithms and a zero-knowledge proof system for a tree-based accumulator. Then we apply the Fiat-Shamir transformation and obtain a secure identity-based ring signature scheme. We prove its security in the random oracle model under the small integer solution assumption.
Identity-based cryptography (IBC) can be applied to scenarios that involve a large number of public keys in each execution. In this paper, we propose an efficient identity-based ring signature scheme on lattices with signature size logarithmic to the cardinality of the ring. To this end, we first construct an efficient identity-based ring identification scheme by combining preimage sampling algorithms and a zero-knowledge proof system for a tree-based accumulator. Then we apply the Fiat-Shamir transformation and obtain a secure identity-based ring signature scheme. We prove its security in the random oracle model under the small integer solution assumption.
This work proposes a Fiat-Shamir linkable ring lattice-based signature scheme, building on Yuen et al. ‘s generic ring signature. It converts the MLWE-based Σ-protocol into a linkable ring signature through the Fiat-Shamir transformation, employing rejection sampling to avoid private key leakage. Linkability is achieved by attaching a public key structure label, avoiding complex zero-knowledge proofs and pseudorandom function calculations. Compared to other lattice-based schemes, our approach improves signature length. Security analysis under the random oracle model confirms correctness, anonymity, unforgeability, linkability, and non-slanderability.
Although most existing linkable ring signature schemes on lattice can effectively resist quantum attacks, they still have the disadvantages of excessive time and storage overhead. This paper constructs an identity-based linkable ring signature (LRS) scheme over NTRU lattice by employing the technologies of trapdoor generation and rejection sampling. The security of this scheme relies on the small integer solution (SIS) problem on NTRU lattice. We prove that this scheme has unconditional anonymity, unforgeability, and linkability under the random oracle model (ROM). Through the performance analysis, 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 has a shorter signature size compared with other existing latest lattice-based LRS schemes. 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. Finally, we implemented our scheme and other similar schemes, and it is shown that the time for the signature generation and verification of this scheme decreases roughly by 44.951% and 33.503%, respectively.
So far, most ring signature schemes rely on hard number theory problems, such as discrete logarithm, bilinear pairings and so on. Unfortunately, the above underlying number theory problems will be solvable in the post quantum era. Lattice-based cryptography is a hotspot of research recently, due to its implementation simplicity and provable security reductions. When the hash-and-sign signature scheme was constructed based on the hardness of worst-case lattice problems, provably secure lattice-based ring signature schemes were finally constructed. However, the hash-and-sign ring signatures were rather inefficient (with megabytes long signatures). In this paper, we propose an alternative method for constructing lattice-based and identity-based ring signature scheme which does not use the hash-and-sign methodology. In the random oracle model, the proposed signature scheme based on the problem in general lattices is unforgeable and holds anonymity. Compared with the previous instantiations of the hash-and-sign ring signature schemes, the lengths of secret key, public key and signatures in the proposed scheme are much shorter. The signing algorithm is quite simple, with matrix-vector multiplications and rejection samplings.
So far, most ring signature schemes rely on hard number theory problems, such as discrete logarithm, bilinear pairings and so on. Unfortunately, the above underlying number theory problems will be solvable in the post quantum era. Lattice-based cryptography is a hotspot of research recently, due to its implementation simplicity and provable security reductions. When the hash-and-sign signature scheme was constructed based on the hardness of worst-case lattice problems, provably secure lattice-based ring signature schemes were finally constructed. However, the hash-and-sign ring signatures were rather inefficient (with megabytes long signatures). In this paper, we propose an alternative method for constructing lattice-based and identity-based ring signature scheme which does not use the hash-and-sign methodology. In the random oracle model, the proposed signature scheme based on the problem in general lattices is unforgeable and holds anonymity. Compared with the previous instantiations of the hash-and-sign ring signature schemes, the lengths of secret key, public key and signatures in the proposed scheme are much shorter. The signing algorithm is quite simple, with matrix-vector multiplications and rejection samplings.
Identity-based ring signature is the combination of the identity-based cryptography and ring signature.It can be used in many practical applications.Most of the existing identity-based ring signatures are based the bilinear pairing assumption.How ever,bilinear pairing problem is no longer hard in the quantum era.To construct an identity-based ring signature securing in the quantum era,in this paper,we presented an identity-based ring signature scheme based on lattices.The scheme is secure in the standard model.The security of scheme is based on the standard small integer solution(SIS) assumption.Compared with other identity-based ring signature schemes from lattices in the standard model,our scheme enjoys higher efficiency.
Although the current lattice-based ring signcryption scheme resists quantum attacks,it has large key storage and high encryption/decryption time.The linkable lattice ring signcryption scheme not only can protect signer anonymity,but also can determine whether two signatures are generated by the same signer.Thus,based on the compact Gaussian sampling algorithm and rejection sampling technique,the identity-based linkable ring signcryption scheme is constructed on the NTRU lattice.Firstly,the system master key is generated using the trapdoor generation algorithm on the NTRU lattice.Then private keys of ring members are obtained based on the compact Gaussian sampling algorithm.Finally,the user signature is generated using rejection sampling,and the key encapsulation mechanism encrypts the signature.Security proof in the random oracle model (ROM) that DRLWE and NTRU small integer solutions are difficult to solve ensures confidentiality,unforgeability,unconditional anonymity,and linkability.Performance analysis shows that compared to the lattice-based ring signcryption and linkable ring signature schemes on NTRU,the proposed scheme has a smaller public key and lower encryption/decryption cost,greatly improving efficiency.