To address the limitation that existing periodically deniable ring signature schemes rely on conventional cryptographic assumptions and were difficult to meet the requirements of post-quantum security, a periodically deniable ring signature scheme based on the Hamming quasi-cyclic (HQC) code-based cryptosystem was proposed. The scheme used the linear consistency relation induced by the HQC public key as the proof statement and constructed a non-interactive ring signature by combining a Stern-like Σ protocol, OR composition, and the Fiat-Shamir transformation. A time-window mechanism was introduced for periodic control of confirmation and disavowal. In the random oracle model, the scheme is proved secure based on support recovery and quasi-cyclic syndrome decoding decision problems, achieving unforgeability, anonymity, traceability, and non-slanderability. The analysis shows that the scheme achieves the unification of post-quantum sealrity, non-repucliation and periodic control with in the encooling framework.
To address the limitation that existing periodically deniable ring signature schemes rely on conventional cryptographic assumptions and were difficult to meet the requirements of post-quantum security, a periodically deniable ring signature scheme based on the Hamming quasi-cyclic (HQC) code-based cryptosystem was proposed. The scheme used the linear consistency relation induced by the HQC public key as the proof statement and constructed a non-interactive ring signature by combining a Stern-like Σ protocol, OR composition, and the Fiat-Shamir transformation. A time-window mechanism was introduced for periodic control of confirmation and disavowal. In the random oracle model, the scheme is proved secure based on support recovery and quasi-cyclic syndrome decoding decision problems, achieving unforgeability, anonymity, traceability, and non-slanderability. The analysis shows that the scheme achieves the unification of post-quantum sealrity, non-repucliation and periodic control with in the encooling framework.
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.
In cryptography, a ring signature is anonymous as it hides the signer’s identity among other users. When generating the signature, the users are arranged as a ring. Compared with group signatures, a ring signature scheme needs no group manager or special setup and supports flexibility of group choice. However, the anonymity provided by ring signatures can be used to conceal a malicious signer and put other ring members under suspicion. At the other extreme, it does not allow the actual signer to prove their identity and gain recognition for their actions. A deniable ring signature is designed to overcome these disadvantages. It can initially protect the signer, but if necessary, it enables other ring members to deny their involvement, and allows the real signer to prove who made the signed action. Many real-world applications can benefit from such signatures. Inspired by the requirement for them to remain viable in the post-quantum age, this work proposes a new non-interactive deniable ring signature scheme based on lattice assumptions. Our scheme is proved to be anonymous, traceable and non-frameable under quantum attacks.
This paper proposes a quantum ring blind signature scheme with revocable anonymity. In this scheme, the message holder blinds the quantum state message through the quantum revolving gate to ensure blindness, the signer uses the random number calculation to compute the generated commitment combined with the quantum revolving gate to obtain the quantum state signature, and the verifier verifies the validity of the signature through the SWAP test. The scheme introduces revocable tags maintained by trusted third parties, which can trace the identity of the signer when necessary, achieving conditional anonymity of signatures. Under the quantum stochastic oracle model, the analysis proves that it meets the requirements of unforgeability and anonymity. Compared with the existing scheme, this scheme integrates ring signatures, blind signatures, and revocable anonymity for the first time under the quantum framework, achieving a balance between privacy protection and compliance supervision.
With the rapid development of quantum computers and quantum computing, Internet of Things (IoT) networks equipped with traditional cryptographic algorithms have become very weak against quantum attacks. This paper focuses on the privacy-preserving problem in IoT networks and proposes a certificateless ring signature (CLRS) scheme. This CLRS is constructed with lattice theories, which show promising advantages in resisting quantum attacks. Meanwhile, the certificateless mechanism reduces the key control ability of the key generation center (KGC) by adding personal secret keys to the private key generated by the system. Meanwhile, the ring signature mechanism protects users' privacy information through a non-central control mechanism. Next, the security proof in a random oracle model is given, which shows that this CLRS scheme can obtain unforgeability and ensure the signer's anonymity. Its security properties include non-repudiation, traceability, and post-quantum security. Then, the efficiency comparison and performance results show that this CLRS scheme is more efficient and practical than similar schemes. Moreover, this work presents an exploration of the post-quantum cryptographic algorithm and its application in IoT networks.
A ring signature (RS) scheme enables a group member to sign messages on behalf of its group without revealing the definite signer identify, but this also leads to the abuse of anonymity by malicious signers, which can be prevented by traceable ring signatures (TRS). Up until that point, traceable ring signatures have been secure based on the difficult problem of number-theoretic (discrete logarithms or RSA), but since the advent of quantum computers, traditional traceable ring signatures may no longer be secure. Thus Feng proposed a lattice based TRS, which are resistant to attacks by quantum computers. However, that works did not tackle the certificate management problem. To close this gap, a quantum-resistant certificateless TRS scheme was proposed in the study. To the best of our knowledge, this is the first lattice based certificateless TRS. In detail, a specific TRS scheme was combined with the lattice-based certificateless signature technology to solve the certificate management problem while avoid key escrow problem. Additionally, a better zero-knowledge protocol is used to improve the computational efficiency of the scheme, and by reducing the soundness error of the zero-knowledge protocol, the number of runs of the zero-knowledge protocol is reduced, so that the communication overhead of the scheme is reduced. Under random oracle model, the proposed scheme satisfies tag-linkability, anonymity, exculpability and is secure based on the SIS problem and the DLWE problem. In conclusion, the proposed scheme is more practical and promising in e-voting.
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.