Ring Signature Scheme Research Articles

An Efficient Multilayered Linkable Ring Signature Scheme With Logarithmic Size for Anonymous Payment in Vehicle-to-Grid Networks

Vehicle-to-Grid (V2G) networks are emerging as an outstanding technique for alleviating energy and environmental concerns. Whereas, malicious attackers thirst for private information from frequent electricity/service exchanges between electric vehicles (EVs) and smart grids (SG) in V2G networks. Several attempts have been made to use ring signatures to achieve privacy-preserving payment and ensure reliable services in V2G. Nevertheless, most of the existing ring signature-based payment proposals may still have numerous limitations in the V2G paradigm due to their heavy signature size. To address the aforementioned problem, we propose Emularis, an efficient multilayered linkable ring signature scheme with a logarithmic size. Specifically, we implement an anonymous payment scheme for V2G using Emularis. We then prove that Emularis guarantees security and privacy requirements through rigorous security analysis. Furthermore, our scheme significantly outperforms existing schemes in terms of communication and computation costs. Extensive experimental results indicate that our scheme is suitable for deployment in V2G security-related applications.

On the security of multivariate-based ring signature and other related primitives

The multivariate public-key cryptography (MPKC) provides a promising class of post-quantum signature schemes. Its theoretical security comes from the intractability of the multivariate quadratic problem (MQ problem), which is an NP-hard problem [1]. Nevertheless, not every instance of MQ-problem is hard [2–6] while the problem itself is NP-hard. Thus, it is important to understand and analyze the nature of the quadratic systems used in existing MPKC so that the security of the multivariate schemes can be properly assessed. Herein, we present a detailed cryptanalysis of the multivariate based ‘ring’ signature scheme presented by Wang et al. [7]. We utilize the attacks on the underdetermined system of multivariate quadratic equations. We prove both theoretically and experimentally that the scheme (Wang et al. [7]) can be broken in polynomial time even for rings of small size. Additionally, we observed that the attack strategy we proposed in this work is not only limited to [7], but can also be applied to break the unforgeability of other multivariate based schemes such as verifiable ring signature scheme [8], multivariate group signature scheme [9], and Gui and GeMSS based ring signature scheme [10,11].

A privacy‐preserving model for blockchain‐based data sharing in the industrial internet

AbstractInformation technology is an important direction for the development of traditional industries. With the in‐depth study of the industrial internet and blockchain technology in recent years, data‐sharing based on blockchain has become an important means to achieve industrial internet interconnection and has played an important role in achieving production efficiency and product quality. However, the transparency of blockchain can raise privacy issues, and competitors may engage in malicious competition due to the exposure of blockchain transactions. Therefore, based on the general blockchain system, this article unifies the scale of value of data sharing by introducing a token exchange mechanism as a basis for privacy‐preserving mechanisms. Based on smart contracts, a token mixer anonymizes shared participants. By introducing a ring signature scheme with smart contracts, we provide group‐oriented authentication for anonymous identities participating in data sharing and ensure data flow within a controlled range. The abovementioned mechanism provides a feasible solution for the privacy‐preserving requirement of data sharing among industrial entities and could encourage industrial entities to participate in data sharing, supporting the goals of interconnection in the industrial internet.

Supersingular Isogeny-based Ring Signature

The increasing demand for secure and anonymous transactions raises the popularity of ring signatures, which is a digital signature scheme that allows identifying a group of possible signers without revealing the identity of the actual signer. This paper presents efficient supersingular isogeny-based ring signature and linkable ring signature schemes that will find potential applications in post-quantum technologies. We develop the ring signature scheme by applying the Fiat-Shamir transform on the sigma protocol for a ring which we obtain from the supersingular isogeny-based interactive zero-knowledge identification scheme by adopting the scheme for a ring. We also extend our ring signature protocol with an additional parameter, i.e., a tag that provides to detect if a signer issues two signatures concerning the same ring by preserving anonymity and linkable anonymity. The signature size of our ring signature protocols increases logarithmically in the size of the ring thanks to the Merkle trees. We show the security proofs and efficiency analyses of the protocols offered. Moreover, we provide the implementation results of the supersingular isogeny-based ring signature, which offers small signature sizes for NIST post-quantum security levels.

PRIVACY PRESERVATION FOR TRANSACTION INITIATORS: STRONGER KEY IMAGE RING SIGNATURE AND SMART CONTRACT-BASED FRAMEWORK

Recently, blockchain technology has garnered support. However, an attenuating factor to its global adoption in certain use cases is privacy-preservation owing to its inherent transparency. A widely explored cryptographic option to address this challenge has been ring signature which aside its privacy guarantee must be double spending resistant. In this paper, we identify and prove a catastrophic flaw for double-spending attack in a Lightweight Ring Signature scheme and proceed to construct a new, fortified commitment scheme using the signer’s entire private key. Subsequently, we compute a stronger key image to yield a double-spending-resistant signature scheme solidly backed by formal proof. Inherent in our solution is a novel, zero-knowledge-based, secured and cost-effective smart contract for public key aggregation. We test our solution on a private blockchain as well as Kovan testnet along with performance analysis attesting to efficiency and usability and make the code publicly available on GitHub.

An in-situ authentication with privacy preservation scheme for accident response in Internet of Vehicles

Real-time monitoring and handling of traffic in large urban cities, remains challenging due to a broad range of technical and non-technical factors. For example, while real-time incident reporting with supporting data (e.g., images or video feeds) can inform decision-making and facilitate traffic control, there are operational challenges (e.g., bandwidth and security). Hence, we propose an identity authentication and privacy preservation scheme based on both blockchain and ring signature. Specifically, in our approach, blockchain is leveraged to maintain anonymity yet guaranteeing traceability. We also design a new ring signature scheme based on the SM2 algorithm and analyze its security. To demonstrate utility, we evaluate our proposed approach using Ethereum smart contracts, and the findings demonstrate that our approach is efficient, supports privacy preservation, and is resilient to a range of common attacks.

A Lattice-Based Certificateless Traceable Ring Signature Scheme

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.

On The Impossibility of Providing Strong Anonymity in Blockchains via Linkable Ring Signatures

<p>Anonymity is a necessary property for a ring signature scheme and also its variant such as linkable ring signature and traceable ring signature schemes, which are especially useful in blockchains. Intuitively, those variants were designed for detecting or seeking the dishonest signatory, however, at the cost of reducing the anonymity of a traditional ring signature. As a result, while various constructions of strongly anonymous ring signatures were well-known, a linkable ring signature scheme with the same property was an open problem for a long time. In this work, we launched a so-called denying attack to show the gap between an arbitrary ring signature and linkable ring signature transparently, which further confirmed the widely believed impossibility in building a linkable ring signature with both strong anonymity and strong linkability. For a concrete instance, we also applied this attack to the scheme in IEEE TKDE, which to the best of our knowledge is the unique linkable ring signature both with strong anonymity and strong linkability so far. The concrete attack is easily launched in blockchain so that it shows the impossibility of providing strong anonymity via linkable ring signature for blockchain applications, since strong likability is indispensable.</p> <p> </p>

AQRS: Anti-quantum ring signature scheme for secure epidemic control with blockchain

Epidemics, such as Corona Virus Disease 2019 (COVID-19), have serious consequences globally, of which the most effective way to control the infection is contact tracing. Nowadays, research related to privacy-preserving epidemic infection control has been conducted, nevertheless, current researchers do not regard the authenticity of records and infection facts as well as poor traceability. Moreover, with the emergence of quantum computing, there is a bottleneck in upholding privacy, security and efficiency. Our paper proposes a privacy-preserving epidemic infection control scheme through lattice-based linkable ring signature in blockchain, called AQRS. Firstly, our scheme adopts a blockchain with three ledgers to store information in a distributed manner, which offers transparency and immunity from the Single Point of Failure (SPoF) and Denial of Service (DoS) attacks. Moreover, we design a lattice-based linkable ring signature scheme to secure privacy-preserving of epidemic infection control. Significantly, we are the first to introduce the lattice-based linkable ring signature into privacy preserving in epidemic control scenario. Security analysis indicates that our scheme ensures unconditional users anonymity, record unforgeability, signature linkability, link non-slanderability and contact traceability. Finally, the comprehensive performance evaluation demonstrates that our scheme has an efficient time-consuming, storage consumption and system communication overhead and is practical for epidemic and future pandemic privacy-preserving.

A Novel Linkable Ring Signature on Ideal Lattices

In this paper, a novel linkable ring signature scheme is constructed. The hash value of the public key in the ring and the signer's private key are based on random numbers. This setting makes it unnecessary to set the linkable label separately for our constructed scheme. When judging the linkability, it is necessary to determine whether the number of the intersections of the two sets reaches the threshold related to the number of the ring members. In addition, under the random oracle model, the unforgeability is reduced to the SVPγ problem. The anonymity is proved based on the definition of statistical distance and its properties.

Cryptanalysis of multivariate threshold ring signature schemes

Petzoldt et al. proposed the first multivariate threshold ring signature scheme extending the idea of a ring identification scheme in 2013. They claimed that their t-out of n threshold ring signature satisfies the security properties of unforgeability and source anonymity. Later, Zhang-Zhao in 2014 and Duong et al. in 2021 proposed other multivariate threshold ring signature schemes using different tools with the same technique. In this article, we cryptanalyze all these schemes and give an attack on their source anonymity which shows how the verifier can find the actual set of signers after some finite number of trials, viz., with at most N=(nn−t)+(nn−t−1)+…+(n1)+(n0) in t-out of n threshold ring.

Identity-based ring signature scheme with multi-designated verifiers

As far as we know, there is only one ring signature scheme with multi-designated verifiers in the literature and the scheme is based on the bilinear pairings which need to consume a lot of computation and under the traditional public key infrastructure (PKI). In order to improve computational efficiency and solve the problem of certificate management in PKI, in this paper, we propose the first identity-based ring signature scheme with multi-designated verifiers without pairings. We prove that our novel scheme's unforgeability, anonymity in the random oracle model and indistinguishability in the standard model under the intractability assumption of discrete logarithm problem and decisional Diffie-Hellman problem, and we prove that our novel scheme's non-transferability in the standard model. We compare the new scheme with a previous scheme in terms of computation and communication at last. The results show that our new scheme is more efficient than the previous scheme and is more suitable for the multi-user setting.

Identity-based ring signature scheme with multi-designated verifiers

Identity-based ring signature scheme with multi-designated verifiers

Efficient identity-based ring identification scheme and identity-based ring signature scheme on lattices

Efficient identity-based ring identification scheme and identity-based ring signature scheme on lattices

Using GeMSS128 in a ring signature scheme

Using GeMSS128 in a ring signature scheme

CRBFT: An Optimized Blockchain Algorithm for Edge-Based IoT System

In this article, a credit identity ring optimization blockchain algorithm (CRBFT) based on practical Byzantine fault tolerance (PBFT) is proposed to address the security problem for the network of Internet of Things (IoT). The contributions of this work are given as follows. First, combined with the edge computing architecture, CRBFT introduces the improved credit grading protocol and the improved ring signature scheme into the blockchain network, rewards or punishes the nodes through their behavior, changes the way of selecting the primary node, and ensures that the identity of the primary node will not be disclosed, so as to prevent the primary node from adaptive attack by Byzantine nodes, improve the reliability of the nodes participating in the consensus, and enhance the security of the system. Second, in order to reduce the communication traffic among nodes, CRBFT optimizes the consensus protocol, which not only reduces the time complexity of the traffic in the consensus stage from O ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${n}^{{2}}$ </tex-math></inline-formula> ) to O ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${n}$ </tex-math></inline-formula> ) but also improves the consensus efficiency of the system while ensuring the system security. Finally, CRBFT aims to measure the performance of CRBFT. This article is simulated and tested in three aspects: throughput (transactions per second), consistency delay, and communication overhead. Performance evaluation shows that CRBFT achieves lower communication overhead than PBFT. When the number of nodes is the same, CRBFT can obtain higher TPS and lower consistency delay. The results show that compared with PBFT, CRBFT can provide very competitive results.

A certificateless ring signature scheme based on lattice

SummaryFor the problems that ring signature needs key escrow, has some security risks, and cannot avoid malicious key generation center (KGC) in the post‐quantum era, we design a certificateless ring signature scheme based on lattice (L‐CRSS). In our scheme, the bimodal Gaussian distribution is used to improve the security and efficiency. Compared with the previous ring signature scheme based on lattice, our design does not need key escrow, does not disclose the signer's identity, can avoid malicious KGC, achieves the constant signature size, and has higher security and efficiency in the post‐quantum era. Finally, under random oracle model (ROM), we prove that our scheme is anonymous against the full‐key exposure, and existentially unforgeable against adaptive chosen message attacks (EUF‐CMA).

Shorter Linkable Ring Signature Based on Middle-Product Learning with Errors Problem

Abstract DualRing is a novel generic construction introduced by Yuen et al. (CRYPTO’21), which can transform a special kind of (Type-T*) canonical identification scheme to a ring signature scheme. Compared with the classical approaches, this method can get a shorter signature. In this paper, we construct a new middle-product learning with errors (MPLWE)-based ring signature scheme by using this framework. Specifically, we propose a new MPLWE-based identification scheme, which is compatible with the DualRing, then we obtain a ring signature scheme by using DualRing framework. We also show how to achieve linkability from this ring signature by using a collision resistant hash function. In the end, we provide available parameter options for our (linkable) ring signature scheme. Under these parameters, the signature size of our linkable ring signature is $2-40 \times $ shorter (depending on the ring size) than the previous MPLWE-based scheme by Das et al. (Africacrypt’19).

Efficient Lattice-Based Ring Signature Scheme without Trapdoors for Machine Learning.

Machine learning (ML) and privacy protection are inseparable. On the one hand, ML can be the target of privacy protection; on the other hand, it can also be used as an attack tool for privacy protection. Ring signature (RS) is an effective way for privacy protection in cryptography. In particular, lattice-based RS can still protect the privacy of users even in the presence of quantum computers. However, most current lattice-based RS schemes are based on a strong trapdoor like hash-and-sign, and in such constructions, there is a hidden algebraic structure, that is, added to lattice so that the trapdoor shape is not leaked, which greatly affects the computational efficiency of RS. In this study, utilizing Lyubashevsky collision-resistant hash function over lattice, we construct an RS scheme without trapdoors based on ideal lattice via Fiat‒Shamir with aborts (FSwA) protocol. Regarding security, the proposed scheme satisfies unconditional anonymity against chosen setting attacks (UA-CSA), which is stronger than anonymity against full key exposure (anonymity-FKE), and moreover, our scheme satisfies unforgeability with respect to insider corruption (EU-IC). Regarding computational overhead, compared with other RS schemes that satisfy the same degree of security, our scheme has the highest computational efficiency, the signing and verification time costs of the proposed scheme are obviously better than those of other lattice-based RS schemes without trapdoors, which is more suitable for ML scenarios.

Representative Ring Signature Algorithm Based on Smart Contract

Traditional ring signature algorithms suffer from large signature data capacity and low speed of signature and verification during collective signing. In this work, we propose a representative ring signature algorithm based on smart contracts. By collecting the opinions of the signatory based on multiparty secure computation, the proposed technique protects the privacy of the signatory during the data interaction process in the consortium chain. Moreover, the proposed method uses smart contracts to organize the signature process and formulate a signature strategy of “one encryption per signature” to prevent signature forgery. It uses the Hyperledger Fabric framework as the signature test platform of the consortium chain to perform the experiments. We compare the results of the proposed method with the ECC ring signature scheme. The experimental results show that in the worst case, the signature volume of the proposed method decreases by more than two times, and the signature speed and verification speed increase by more than three times. Therefore, in the collective signature scenario of transaction verification in the consortium chain, the proposed method is verified to be innovative and practical.