Ring Signature Scheme Research Articles

Post-Quantum Secure ID-Based (Threshold) Linkable Dual-Ring Signature and Its Application in Blockchain Transactions

Ring signatures are widely used in e-voting, anonymous whistle-blowing systems, and blockchain transactions. However, due to the anonymity of ring signatures, a signer can sign the same message multiple times, potentially leading to repeated voting or double spending in blockchain transactions. To address these issues in blockchain transactions, this work constructs an identity-based linkable ring signature scheme based on the hardness of the lattice-based Module Small Integer Solution (M-SIS) assumption, which is hard even for quantum attackers. The proposed scheme is proven to be anonymous, unforgeable, linkable, and nonslanderable in the random oracle model. Compared to existing identity-based linkable ring signature (IBLRS) schemes of linear size, our signature size is relatively smaller, and this advantage is more pronounced when the number of ring members is small. We provide approximate signature size data for ring members ranging from 2 to 2048. When the number of ring members is 16 (or 512. resp.), the signature size of our scheme is 11.40 KB (or 24.68 KB, respectively). Finally, a threshold extension is given as an additional scheme with specifications and security analysis.

Efficient message authentication scheme with forward and backward security in Vehicle Cloud Network towards sustainable smart city

The Vehicular Cloud Network (VCN) serves as a crucial component of Intelligent Transportation Systems (ITS), playing an instrumental role in the development of sustainable smart cities. It merges the benefits of both Vehicular Ad Hoc Networks (VANET) and cloud computing. However, VCN faces significant security challenges due to the complexity of communication, the dynamic nature of the environment, and the privacy concerns of data. To address the issues of message security and privacy preservation in VCN, this paper introduces an identity-based key-insulated ring signature (ID-KIRS) scheme for VCN message authentication. Our scheme integrates a secure key update function to address key exposure issues, providing both forward and backward security. The security analysis confirms that our scheme ensures message integrity, unconditional anonymity, and unforgeability. The performance evaluation clearly demonstrates our scheme is efficient, and applicable to vehicle congestion situations, especially car accident scenarios.

Revocable ring signatures with CCA-anonymity from standard lattices

Ring signatures are significant cryptographic primitives used for anonymous authentication due to their anonymity and spontaneity. However, in some scenarios, they may offer excessive anonymity to the signer. Revocable ring signatures aim to preserve the desirable properties of ring signatures while incorporating the accountability aspect of group signatures, leading a better trade-off between anonymity and accountability. Nevertheless, most revocable ring signature schemes only provide relatively weak CPA-Anonymity. In this paper, we present an instantiation of CCA-Anonymity from standard lattices, and prove its security under the random oracle model. Our construction achieves stronger anonymity and revocability, while relying on weaker assumptions than existing schemes from module lattices. Moreover, it boasts smaller sizes when the ring is large.

Deniable ring signature scheme based on the ISRSAC digital signature algorithm

This article introduces a deniable ring signature scheme within the framework of a ring signature protocol, which allows a member of the ring to assert or deny their role as the signature’s originator without the involvement of a trusted third party. Deniable ring signatures find applications in various scenarios where balancing privacy protection with supervised oversight is crucial. In this work, we present a novel deniable ring signature scheme based on the ISRSAC digital signature, tailored for environments with regulatory requirements, empowering regulators to hold malicious signers accountable. We formally validate the scheme’s correctness, unforgeability, anonymity, traceability, and non-frameability through rigorous proofs. Additionally, we conduct a comparative analysis of the communication and computational overheads associated with our proposed scheme, demonstrating its superiority in practical scenarios such as electronic auctions and anonymous reporting mechanisms.

Linkable ring signature scheme with stronger security guarantees

Ring signatures enable a user to sign messages on behalf of an arbitrary set of users, called the ring. The signer-anonymity property guarantees that the signature does not reveal which member of the ring signed the message. The notion of linkable ring signatures (LRS) is an extension of the concept of ring signatures such that there is a public way of determining whether two signatures have been produced by the same signer. However, the existing LRS schemes may not be competent in some scenarios since they exhibit a gap to bridge as reflected on the security guarantees such as the absence of quantum-resistance, inadequate security notions, and a reliance on the random oracle heuristic.In this paper, we present a framework for LRS that provides stronger security guarantees. We instantiate the framework from standard lattice assumptions and prove the security in the standard model. Furthermore, we implement our scheme and conduct experimental evaluations, which demonstrate that the performances are practical for typical settings.

CPPA-RORS: A conditional privacy-preserving authentication scheme based on revocable one-time ring signature for VANETs

Vehicular ad-hoc networks (VANETs) are a wireless communication system designed to improve driving safety and traffic management, with a focus on enhancing road traffic efficiency and safety. Privacy protection is one of the crucial security challenges for VANETs. However, considering the high mobility of vehicles that frequently transmit delay-intolerant safety and informative messages, two problems exist in some ring signature-based conditional privacy-preserving authentication (CPPA) schemes for VANETs: first, vehicles cannot detect the malicious vehicles when a malicious vehicle signs a message multiple times; and second, the TAs cannot reveal vehicles’ identities when some vehicles engage in illegal activities. To address these concerns, we propose a CPPA scheme based on revocable one-time ring signature (CPPA-RORS) scheme, leveraging the properties of ring signatures. The scheme ensures anonymity of the honest vehicles while providing TAs with the ability to reveal malicious vehicles at any time. We allow one vehicle only can sign one signature on one message, called one-time, to safeguard vehicle privacy with high security. CPPA-RORS scheme provides the formal security model for VANETs, and in particular simultaneously offers message-linkability and mandatory revocability, effectively preventing the double-spending attack (Shrestha et al. 2020) and enabling TAs to revoke the anonymity of any vehicle at any time for further enhancing the security and trustworthiness of the networks. Theoretical analysis and experimental results show that CPPA-RORS provides robust security measures and privacy for vehicles in VANETs.

A logarithmic-sized accountable ring signature scheme in the standard model

Ring signature and group signature are two major cryptographic primitives providing users anonymity and authentication simultaneously. While both primitives enable any user to sign messages as a member of a set of users, the feature of ring signature is that a signer can choose a group in an ad-hoc manner, which is called a ring, by itself. Conversely, in group signature, a group membership is managed by some trusted third party, which is called a group manager, and an (appropriate) accountability is provided for the group manager to identify illegal anonymous signers. Accountable ring signature (ARS) is a cryptographic primitive combining the features of ring signature and group signature. ARS allows signers to choose their groups (rings) in an ad-hoc manner, and at the same time, maintain accountability by forcing them to select a designated opener who can identify them.In this paper, we propose the first ARS scheme with O(log⁡n) signature size in the standard model (without depending on the random oracle methodology), where n is the size of a ring. More precisely, we propose a new generic construction of ARS based on (standard) signature, (standard) public key encryption, non-interactive zero-knowledge proof system, somewhere perfectly binding hash function, and public key encryption with non-interactive opening. All building blocks for our ARS scheme can be obtained under the decisional linear (DLIN) assumption over bilinear groups.

On the Black-Box impossibility of multi-designated verifiers signature schemes from ring signature schemes

Abstract From the work by Laguillaumie and Vergnaud in ICICS’04, it has been widely believed that multi-designated verifiers signature scheme (MDVS) can be constructed from ring signature schemes in general. However, in this article, somewhat surprisingly, we prove that it is impossible to construct an MDVS scheme from a ring signature scheme in a black-box sense (in the standard model). The impossibility stems from the difference between the definitions of unforgeability of the two schemes. To the best of our knowledge, existing works demonstrating the constructions do not provide formal reductions from an MDVS scheme to a ring signature scheme, and thus, the impossibility has been overlooked for a long time.

A Bilinear Mapping Based Ring Signature Scheme with Batch Verification for Applications in VANETs

A Bilinear Mapping Based Ring Signature Scheme with Batch Verification for Applications in VANETs

Traceable ring signature schemes based on SM2 digital signature algorithm and its applications in the data sharing scheme

Traceable ring signature schemes based on SM2 digital signature algorithm and its applications in the data sharing scheme

RSHealth: A Ring Signature Scheme for Identity Anonymization and Transaction Privacy in Blockchain Based E-Healthcare Systems

RSHealth: A Ring Signature Scheme for Identity Anonymization and Transaction Privacy in Blockchain Based E-Healthcare Systems

Blockchain-Enabled Privacy-Preserving Authentication Mechanism for Transportation CPS With Cloud-Edge Computing

In this article, we propose a secure and effective blockchain-enabled privacy-preserving authentication scheme for the transportation cyber-physical system (CPS) with the cloud-edge computing environment, which supports unconditional anonymity and data batch integrity verification while greatly simplifying key management issues. The proposed privacy-preserving authentication scheme employs an elliptic curve to construct a pairing-free ring signature scheme, which greatly reduces the resources overhead in the transportation CPS with cloud-edge computing. Moreover, the authentication process is performed on the blockchain to provide more reliable service information for vehicular communication. Furthermore, the security proof of the scheme is demonstrated based on the elliptic curve discrete logarithm problem under the random oracle model, and gives the corresponding security analysis. Finally, a simulation experiment demonstrates that the proposed scheme is feasible compared with the existing schemes.

Quantum-Secure Hybrid Blockchain System for DID-Based Verifiable Random Function with NTRU Linkable Ring Signature

In this study, we present a secure smart contract-based Verifiable Random Function (VRF) model, addressing the shortcomings of existing systems. As quantum computing emerges, conventional public key cryptography faces potential vulnerabilities. To enhance our VRF’s robustness, we employ post-quantum Ring-LWE encryption for generating pseudorandom sequences and a NTRU lattice-based linkable ring signature scheme. Given the computational intensity of this approach and associated on-chain gas costs, we propose a hybrid architecture of VRF system where both on-chain and off-chain can communicate in a scalable and secure way. Our decentralized VRF employs multi-party computation (MPC) with blockchain-based decentralized identifiers (DID), ensuring the collective efforts of enhanced randomness and security. We show the security and privacy advantages of our proposed VRF model with the approximated estimation of overall temporal and spatial complexities. We also evaluate our VRF MPC model’s entropy and outline its Solidity smart contract integration. This research also provides a method to produce and verify the VRF output’s proof, optimal for scenarios necessitating randomness and validation. Lastly, using NIST SP800-22 test suite for randomness, we demonstrate the commendable result with a 97.73% overall pass rate on 11 standard tests and 0.5459 of average 𝑝-value for the total 176 tests.

A novel quantum ring signature based on secret sharing

Quantum signature has become a hot topic in the current research of digital signature schemes due to its unconditional security. As a special kind of digital signature, ring signatures are frequently employed in practical situations because of their superior anonymity. In this work, we propose a quantum ring signature scheme based on secret sharing that does not use entanglement states. To guarantee the complete security of the participants’ secret keys, the idea of secret sharing is incorporated into the quantum key distribution process during the key distribution stage. Each ring member contributes his private key share to the final verification formula through a recursive relationship throughout the signing and verification phases, and the verifier can utilize his private key share along with the user’s public key to confirm the ring members’ authenticity; The [Formula: see text]-AS2U hash function is used to encrypt the ring signer’s identity during the entire signature process, which assures the signer’s identity’s complete anonymity, effectively protects the signer’s privacy, and is more in line with practical requirements.

New trend for LWE application in different computer science fields

Problems of large keys in the on-lattice ring signature link due to reduce to the lattice, based on the problem of fault-tolerant learning on the ring (RLWE), according to "Homomorphic Commitment→∑-Protocol→Fiat-Shamir Transformation" reconstructs a linkable ring signature scheme on a lattice. First construct a base “Homomorphic commitment scheme” on polynomial ring of RLWE difficult, and use the Fiat-Shamir transformation method. The method converts the ∑-protocol into a linkable ring signature scheme, and suggests linkable ring signature scheme model. It is resistant to quantum computer attacks. compared with the previous linkable ring signature schemes on lattices, proposed methods with high computational, simple and less time frame because the ring elements in the scheme are taken from small polynomials which represents as case of application in computer science.

Secure Ring Signature Scheme for Privacy-Preserving Blockchain.

Blockchain integrates peer-to-peer networks, distributed consensus, smart contracts, cryptography, etc. It has the unique advantages of weak centralization, anti-tampering, traceability, openness, transparency, etc., and is widely used in various fields, e.g., finance and healthcare. However, due to its open and transparent nature, attackers can analyze the ledger information through clustering techniques to correlate the identities between anonymous and real users in the blockchain system, posing a serious risk of privacy leakage. The ring signature is one of the digital signatures that achieves the unconditional anonymity of the signer. Therefore, by leveraging Distributed Key Generation (DKG) and Elliptic Curve Cryptography (ECC), a blockchain-enabled secure ring signature scheme is proposed. Under the same security parameters, the signature constructed on ECC has higher security in comparison to the schemes using bilinear pairing. In addition, the system master key is generated by using the distributed key agreement, which avoids the traditional method of relying on a trusted third authorizer (TA) to distribute the key and prevents the key leakage when the TA is not authentic or suffers from malicious attacks. Moreover, the performance analysis showed the feasibility of the proposed scheme while the security was ensured.

Efficient lattice-based traceable ring signature scheme with its application in blockchain

Traceable ring signatures (TRSs) were proposed by Fujisaki and Suzuki (PKC 2007), which is a variant of ring signatures that aims to restrict excessive anonymity of them. If the signer signs two identical messages about the same group of ring members and issue, the two signatures will be detected, but the identity of the signer will not be disclosed; if the signer signs two different messages about the same group of ring members and issue, it allows to reveal the identity of the signer. This primitive is very useful in scenarios that require anonymous protection and avoid duplicate signatures, such as electronic voting, blockchain and Internet of Things. However, the existing post-quantum TRS schemes all have a long signature and low computational efficiency, which is far from practical application. In this paper, we propose an efficient lattice-based TRS scheme by improving DualRing that is a short ring signature scheme proposed by Yuen et al. (CRYPTO 2021). Among all existing post-quantum TRS schemes, the proposed scheme has the shortest signature for a ring size between 5 and 2000, and it is also the fastest one in signature generation, taking only about 0.4 s for a ring size of 1024. In the random oracle model, the proposed scheme is proved to satisfy anonymity, tag-linkability and exculpability under the Module Short Integer Solution and Module Learning With Errors hardness assumptions over lattice. In addition, to demonstrate the applicability of the proposed scheme, we develop a post-quantum blockchain model with access control based on it, which can be extended to Internet of Medical Things (IoMT), e-commerce, education, banking and other systems.

SM2-DualRing: Efficient SM2-based ring signature schemes with logarithmic size

As an equivalent of a handwritten signature, digital signature can resist against information tampering and identity impersonation during digital communication, but it fails to meet the specific anonymity requirement in circumstances like voting, credit reporting, and whistle-blowing. Ring signature was introduced as a special digital signature to further achieve anonymity, and classical schemes constructed from single ring were faced with linearly increasing size. In CRYPTO 2021, Yuen et al. proposed a novel construction paradigm (namely, DualRing) for reaping logarithmic-sized ring signature. Existing DualRing-based ring signature schemes are based on its supported Type-T standard signature algorithms (Three-move type, e.g. Schnorr signature). In this paper, we are motivated to seek a SM2-based ring signature scheme upon the DualRing technology, among which the SM2 digital signature is widely adopted as an international standard but not with a Type-T architecture. Therefore, we first transform the SM2 digital signature into Type-T and integrate DualRing with the variant of the SM2 digital signature. After that, we prove the unforgeability and anonymity of our schemes, together with proposing optimized and linkable schemes. Finally, we put our schemes into practice to display their performance in communication and computation costs.

A lattice‐based blind ring signature scheme for sensitive data protection in blockchain applications

SummaryEvery transaction is made public and verified by a third party, and the transparency of blockchain applications leads to privacy leaks. Everyone can access the transaction, making it easier for network analysis to identify the user's identity, which is a major problem with the blockchain. Financial institutions have become hesitant to adopt blockchain technology; as a result, preventing its spread. To confirm that encryption and security are maintained for transactions in the blockchain, this research introduces a zero‐knowledge proof (ZKP) based transaction validation scheme. To increase the security of blockchain applications, the proposed lattice‐based blind ring signature (LBRS) scheme integrates blind and ring signatures and is applied to sensitive data. The data are encrypted using this encryption scheme before being stored with the transactional information in the blocks. The encrypted data is then stored in the blocks, which users can retrieve after verification. The encrypted data is then stored in blocks, which users can retrieve after verification. A verification scheme based on the ZKP is used to prevent unauthorized access and changes to the data. The proposed LBRS scheme meets the security analysis requirement. The performance of an LBRS scheme is compared to other relevant models in terms of execution time, encryption time, and decryption time. Overall, the results are more encouraging and reassuring than other relevant works of interest. Finally, this model provides better computational security and satisfies the requirements like correctness and security analysis.

Identity verifiable ring signature scheme for privacy protection in blockchain

Identity verifiable ring signature scheme for privacy protection in blockchain