D C Saputro, Noor A Setiawan, Azkario Rizky Pratama, Avinanta Tarigan
The increasing adoption of blockchain technology in education has introduced alternative approaches to identity verification beyond centralized credential systems. This study proposes and implements a decentralized authentication mechanism for Moodle LMS using ERC-721 non-fungible tokens (NFTs) verified through MetaMask. Developed as a proof-of-concept following a design science methodology, the system links on-chain identity tokens to Moodle accounts without storing usernames or passwords. The architecture integrates Ethereum smart contracts, nonce-based digital signature verification, and Moodle’s Role-Based Access Control (RBAC) framework. Functional testing confirms that access is granted exclusively to users possessing valid ERC-721 tokens and verified wallet signatures. Replay attack simulations demonstrate effective resistance through nonce validation, while ensuring that no sensitive credential data is exposed during the authentication process, in contrast to default Moodle login mechanisms. Performance evaluation using Apache JMeter indicates stable operation under moderate loads. Although scalability and token management limitations remain, the results demonstrate the technical feasibility and enhanced security advantages of NFT-based authentication for learning management systems.
GLYPH is a transparent verification layer for Ethereum for trustless on-chain verification of heterogeneous proof systems. It unifies upstream SNARK and STARK settlement through a single packed arity-8 sumcheck verifier over p = 2^128 - 159, while preserving upstream assumptions. The design centers on a universal adapter surface, UCIR compilation, and a chain-bound artifact interface for stateless verification. Benchmark evidence in the whitepaper reports 29.45k total transaction gas in recorded testnet receipts. This record includes the whitepaper and the formal proof appendix.
Li Xu, Mohd Nurul Hafiz Ibrahim, Mustafa Muwafak Alobaedy, S. B. Goyal
This is the first PRISMA-guided systematic review of scalable blockchain digital signatures for healthcare, synthesizing evidence from 85 peer-reviewed studies published between 2015 and 2024. The review examines five thematic areas: digital signatures, consensus mechanisms, smart contracts, hybrid blockchain architectures, and regulatory compliance. Particular emphasis is placed on scalability challenges and the role of alternative consensus protocols, such as Proof-of-Stake and Delegated Proof-of-Authority (DPoA), in addressing the energy and latency limitations of Proof-of-Work (PoW). Findings highlight the value of smart contracts in automating consent and authentication processes, while hybrid blockchain models are shown to balance security with scalability. The synthesis also identifies persistent challenges, including interoperability with legacy systems, energy consumption, and compliance with GDPR and HIPAA regulations. Importantly, emerging approaches such as Layer-2 scaling, AI-enhanced validation, and post-quantum cryptography are highlighted as promising directions. By integrating technical and regulatory perspectives, this review contributes a critical roadmap for researchers, healthcare providers, and system architects seeking secure, efficient, and regulation-compliant blockchain frameworks
We present the Mazari Bidirectional Architecture, a cryptographic framework providing end-to-end privacy guarantees for computation systems employing homomorphic encryption (HE), differential privacy (DP), and zero-knowledge proofs (ZK). The architecture comprises two complementary orderings: Y.I.N. Mazari Ordering (DP→ZK→HE) for secure data submission and Y.A.N.G. Mazari Ordering (VERIFY→DISAGGREGATE→DECRYPT→DENOISE) for secure result retrieval. Through exhaustive permutation analysis, we prove that among all possible orderings for each direction, exactly one ordering in each direction is secure—and these orderings are mathematical duals. The Y.I.N. ordering prevents information leakage during data submission, while the Y.A.N.G. ordering prevents timing side-channel attacks during result retrieval. This paper provides comprehensive coverage of all implementation variations, security proofs, and robustness analysis to establish technical foundations for privacy-preserving computation research.
The article systematizes modern methods of zero-knowledge proof (ZKP). Classification features are considered: protocol interactivity, algebraic or stochastic basis, need for trusted setup, type of zero-knowledge, and proof model. Classical schemes (Fiat–Shamir, Schnorr, Blum), modern zk-SNARK and zk-STARK, as well as novel approaches – PLONK, Halo 2, Bulletproofs, lattice-based ZKPs, and machine learning proofs are described. A comparative analysis is conducted according to efficiency, proof size, generation and verification complexity. It is shown that SNARKs provide compactness but require a trusted setup, while STARKs are transparent and post-quantum secure but large. Open problems are highlighted: recursive proofs, standardization, metadata protection, and applications in machine learning. It is concluded that further research in this field is aimed at creating scalable, secure, and quantum-resistant protocols for digital technologies.
The article systematizes modern methods of zero-knowledge proof (ZKP). Classification features are considered: protocol interactivity, algebraic or stochastic basis, need for trusted setup, type of zero-knowledge, and proof model. Classical schemes (Fiat–Shamir, Schnorr, Blum), modern zk-SNARK and zk-STARK, as well as novel approaches – PLONK, Halo 2, Bulletproofs, lattice-based ZKPs, and machine learning proofs are described. A comparative analysis is conducted according to efficiency, proof size, generation and verification complexity. It is shown that SNARKs provide compactness but require a trusted setup, while STARKs are transparent and post-quantum secure but large. Open problems are highlighted: recursive proofs, standardization, metadata protection, and applications in machine learning. It is concluded that further research in this field is aimed at creating scalable, secure, and quantum-resistant protocols for digital technologies.
In this paper we present BlockMedLedger, a decentralized patient health record management system based on blockchain and IPFS. BlockMedLedger provides solutions to the challenges of healthcare data silos, security vulnerabilities and patient ownership of their own data. The patient centric model supports patients, medical data owners, to have complete control over their own medical data, while providing an efficient process to facilitate secure sharing of the medical data with care providers initiated through smart contracts and cryptographic access controls. The system uses an Ethereum compatible blockchain to support access control decision and IPFS for decentralized encrypted storage of encrypted medical records. The implementation demonstrates good security, efficient access, retrieval and sharing of encrypted health information for health care providers and patients while meeting requirements specified in HIPAA utilizing zero-knowledge proofs and patient consent control features.
This paper presents zero knowledge proofs, their cryptographic significance and applications. It presents a basic classification: interactive and noninteractive zero knowledge proofs. It presents and compares three protocols of non-interactive zero knowledge proofs: ZK-SNARK, ZK-STARK and Bulletproofs. It presents the quadratic residue problem and proofs it with both interactive and non-interactive zero knowledge proofs. The non-interactive protocol used to prove the quadratic residue problem is ZK-SNARK. The proof is implemented in the Python programming language, using python-snark library.
Abstract Fair exchange is a cryptographic protocol that enables two parties to exchange their electronic data fairly, i.e., it ensures that no one can steal the other party’s item. FairSwap and OptiSwap are well-known fair exchange protocols for files and coins based on smart contracts. Although the design principles for the two protocols are similar, there is an extreme difference in round complexity and communication overhead between the two protocols. This gap can be a barrier to users since they must choose one of them. In order to remove the barrier, this work generalizes these two protocols. It proposes a fair exchange protocol that allows users to adjust the communication overhead and the number of rounds by a newly introduced parameter. Our protocol contains FairSwap, OptiSwap, and protocols with intermediate efficiency between them. Moreover, to evaluate the gas costs of our protocol, we present a performance evaluation of the proposed protocol by Solidity implementation over Ethereum.
As vehicular ad hoc networks (VANETs) increase in size and complexity, ensuring secure, flexible, and privacy-preserving vehicle-to-infrastructure (V2I) authentication remains a major challenge. Existing protocols often focus solely on identity verification, overlooking the need for access control based on vehicle attributes. Furthermore, vehicles must obtain authentication credentials from various trusted entities, including automakers, regulators, and government agencies. However, the absence of a unified credential issuance mechanism introduces fragmentation and inconsistencies during the registration process. To address these issues, we propose a V2I authentication protocol, called PriV2I, that integrates distributed credential issuance, attribute-based access control, and strong anonymity guarantees. During vehicle registration, our approach uses Shamir’s Secret Sharing with a threshold t of n across multiple certification authorities (CAs) to consolidate credentials. A vehicle credential can only be issued by a predefined threshold number of CAs, enhancing security and flexibility. Within the authentication protocol, Pointcheval-Sanders (PS) signatures enable fine-grained access control based on vehicle attributes such as type and role. Meanwhile, noninteractive zero-knowledge proofs protect identity privacy by allowing vehicles to prove credential possession and policy compliance without revealing sensitive information. The proposed scheme also supports batch authentication at Roadside Units (RSUs) to efficiently handle high-density environments and includes a comprehensive revocation mechanism to trace and revoke malicious vehicles promptly and securely. In our implementation, the computation cost during the authentication phase is 75.58 ms. The communication overhead per authentication exchange is 992 bytes across two messages. Overall, the protocol provides a secure, scalable, and privacy-preserving solution tailored to modern VANET environments.
Abstract Zero knowledge succinct non-interactive arguments of knowledge protocol (zk-SNARK) is an application oriented variant of zero knowledge proof, which enables a prover to convince a verifier that a statement is true, without revealing any other information beyond the correctness of the statement itself. Due to its powerful capabilities and high efficiency, it has been widely deployed in various blockchain based applications to provide privacy and scalability. While these applications place high demands on small proof size, fast verification and decentralization, currently available zk-SNARK with the shortest proof size and the fastest verification speed is in the common reference string (CRS) model, that is they require the trusted setup. After the pioneering results proposed by Bellare et al. in ASIACRYPT 2016, there have been lots of efforts to construct zk-SNARKs that satisfy subversion zero knowledge (S-ZK) and standard soundness from the zk-SNARK in the CRS model. These constructions could be regarded secure in the bare public key (BPK) model because that the equivalence between S-ZK in the CRS model, and uniform non-black-box zero knowledge in the BPK model has been proved by Abdolmaleki et al. in PKC 2020. Thus, compared to the CRS model, the BPK model better characterizes decentralized blockchain based application such as cryptocurrencies and anonymous credentials. In this study, by leveraging the power of random oracle (RO) model, we proposed the first publicly verifiable non-uniform ZK zk-SNARK scheme in the BPK model maintaining comparable efficiency with its conventional counterpart, which can also be compatible with the well-known transformation proposed by Bitansky et al. in TCC 2013 to obtain an efficient designated-verifier zk-SNARK. We achieve this goal by only adding a constant number of elements into the CRS, and using an unconventional but natural method to transform Groth’s zk-SNARK in EUROCRYPT 2016. In addition, we propose a new speed-up technique that provides a trade-off. Specifically, if a logarithmic number of elements are added into the CRS, according to different circuits, the CRS verification time in our construction could be approximately 9–23% shorter than that in the conventional counterpart.
Existing agent communication frameworks face critical limitations in providing verifiable audit trails without compromising the privacy and confidentiality of agent interactions. The protection of agent communication privacy while ensuring auditability emerges as a fundamental challenge for applications requiring accurate billing, compliance verification, and accountability in regulated environments. We introduce a framework for auditing agent communications that keeps messages private while still checking they follow expected rules. It pairs zero-knowledge proofs with the existing Model Context Protocol (MCP) so messages can be verified without revealing their contents. The approach runs in lightweight networks, stays compatible with standard MCP exchanges, and adds asynchronous audit verification to confirm format and general message types without exposing specifics. The framework enables mutual audits between agents: one side can check communication content and quality while the other verifies usage metrics, all without revealing sensitive information. We formalize security goals and show that zk-MCP provides data authenticity and communication privacy, achieving efficient verification with negligible latency overhead. We fully implement the framework, including Circom-based zero-knowledge proof generation and an audit protocol integrated with MCP's bidirectional channel, and, to our knowledge, this is the first privacy-preserving audit system for agent communications that offers verifiable mutual auditing without exposing message content or compromising agent privacy.
Formal verification of smart contracts is widely regarded as an effective method for ensuring correctness and security properties across all possible executions. Its practical relevance has been driven by the availability of automatic verification tools that discharge intricate proofs. Another area of growing interest is the integration of specification paradigms - for example, combining Hoare-logic–style specifications (pre/postconditions and invariants) with SMT and symbolic reasoning - so that each technique can precisely capture complementary aspects of contract behavior. In this article we present a comparative analysis of four leading Solidity verification tools - solc-verify, SMTChecker, VeriSmart and the Certora Prover - and define what is meant here by a formal verification tool: a system that provides mathematically rigorous proofs that stated properties hold for every possible execution of a contract. We also describe a consistent evaluation framework that considers the Solidity version support, the preservation of the original contract structure, the local execution capability, the verification time, and the modeling-language requirements, among other criteria. We used the ERC-20 token standard as a benchmark and applied this framework to obtain empirical evidence of each tool’s capabilities and limitations. Our results expose substantial variability in the tools performances that undermines their trustworthiness in practice and highlights a gap between an academic tool capabilities and the industrial requirements. Finally, we discuss how these findings can inform developers and researchers in selecting appropriate verification tools, thereby contributing to improved smart contract security and reliability.
This publication introduces Zero-Knowledge Behavioral Proof (ZKBP) as a post-biometric authentication primitive designed for the QADMON canonical security framework. ZKBP replaces traditional biometric and password-based identity with cryptographically verifiable behavioral continuity. The protocol proves liveness, integrity and continuity of behavior without revealing biometric templates, raw behavioral signals, or any permanent human identifier. The package includes: - Formal cryptographic definition of ZKBP - Security proofs under LWE-based post-quantum assumptions - Comprehensive threat model (AI imitation, replay, side-channels, insider threats) - Protocol specification in JSON - Comparative security tables (CSV) - Multilingual human-readable documentation (EN, RU, HE, ZH, AR) - Implementation notes for PQC + TEE environments This module follows the canonical QADMON axiom: FSIG ≠ Cryptographic Key FSIG = Zero-Knowledge Behavioral Proof The only cryptographic secret is a post-quantum key stored inside a Trusted Execution Environment (TEE). This work is published as Module 02 of the QADMON Canonical Security Framework.
Extends the EQBSL (Evidence-Quality Bayesian Subjective Logic) framework with zero-knowledge proof constraints. Allows a prover to demonstrate that their trust opinion was computed correctly from private evidence, without revealing the evidence itself. Bridges cryptographic privacy guarantees with the epistemic trust formalism of EQBSL.
Zero-knowledge proofs (ZKPs) have evolved from foundational interactive proof systems to highly efficient, scalable, and trusted-setup-free constructions powering today’s privacy-preserving and blockchain applications. The field began with the seminal works of Goldwasser, Micali, and Rackoff (GMR) and Goldreich, Micali, Wigderson (GMW) in the 1980s, which introduced interactive proofs, knowledge complexity, and showed that all NP languages admit zero-knowledge proofs. The 1990s brought non-interactive ZK (NIZK) via the CRS model (Blum–Feldman–Micali) and practical sigma-protocols like Schnorr proofs, establishing foundational tools still used today. From the 2000s through early 2010s, research integrated pairings, PCPs, and cryptographic soundness, culminating in pairing-based NIZKs and early succinct argument systems. The SNARK revolution accelerated with QAP-based zk-SNARKs (Gennaro–Gentry–Parno), practical implementations like Pinocchio and libsnark, and the highly efficient Groth16 proving system that became a blockchain standard. Since 2018, the field has shifted toward transparent, universal, and post-quantum-secure systems. Innovations include Bulletproofs (short proofs without trusted setup), zk-STARKs (scalable and PQ-secure), PLONK (universal/updatable setup), and Halo/Halo2 enabling recursive proofs without trusted setup. These advances underpin modern Zcash deployments, zk-rollups, and privacy-preserving scaling systems across Web3. Overall, the ZKP landscape has progressed from theoretical constructs to practical, scalable, and secure systems central to modern cryptography and decentralized computation.
Denis Wapukha Walumbe, Gabriel Kamau, Jane Wanjiru Njuki
With the rising integration of blockchain in critical domains such as healthcare, designing efficient, lightweight, and privacy-preserving consensus mechanisms remain a significant challenge.Existing Proof-of-Stake (PoS) implementations often incur high computational and communication overhead, making them unsuitable for telemedicine systems.This study proposed LightweightPoS, a novel voting mechanism designed for this environment.The proposed mechanism incorporates a cluster-based voting to minimize message complexity, Byzantine Agreement protocol for robust fault tolerance and cryptographic sortition to ensure fairness and privacy.This implementation slashes global communication, reducing message complexity by over 95% compared to traditional PoS models.The study evaluated the proposed and baseline mechanisms through simulations using real-time telemedicine data sensors.The results demonstrated that the proposed mechanism consistently achieved sub-10ms latency, high transaction throughput (up to 2400 TPS) and low energy consumption (~0.002kWh per round).It significantly outperformed baseline mechanism like Algorand and Ouroboros.Furthermore, the system included an effective Byzantine node detection, ensuring reliability under adversarial conditions.This work contributes a practical consensus voting mechanism that balances privacy and regulatory compliance.It provides a robust foundation for deploying blockchain technology in privacy-sensitive telemedicine applications.
One-Time Passwords (OTPs) are a core component of multi-factor authentication in banking, e-commerce, and digital platforms. However, conventional delivery channels such as SMS and email are increasingly vulnerable to SIM-swap fraud, phishing, spoofing, and session hijacking. This study proposes an end-to-end mobile authentication architecture that integrates a permissioned Hyperledger Fabric blockchain for tamper-evident identity management, an AI-driven risk engine for behavioral and SIM-swap anomaly detection, Zero-Knowledge Proofs (ZKPs) for privacy-preserving verification, and geolocation-bound OTP validation for contextual assurance. Hyperledger Fabric is selected for its permissioned governance, configurable endorsement policies, and deterministic chaincode execution, which together support regulatory compliance and high throughput without the overhead of cryptocurrency. The system is implemented as a set of modular microservices that combine encrypted off-chain storage with on-chain hash references and smart-contract–enforced policies for geofencing and privacy protection. Experimental results show sub-0.5 s total verification latency (including ZKP overhead), approximately 850 transactions per second throughput under an OR-endorsement policy, and an F1-score of 0.88 for SIM-swap detection. Collectively, these findings demonstrate a scalable, privacy-centric, and interoperable solution that strengthens OTP-based authentication while preserving user confidentiality, operational transparency, and regulatory compliance across mobile network operators.
Provable security is a cornerstone of modern cryptography: Due to ubiquitous and diverse applications of cryptography, a proof of security gives us the necessary confidence to deploy a cryptographic protocol. In most cases, such a security proof comes in the form of a black-box reduction, which bases the security of a potentially complex protocol on a small set of simple and abstract assumptions that are much easier to analyse. However, proving a black-box reduction can be quite complicated, and we do not have proofs for every protocol used in practice. Here, analysing the protocols relative to oracles, a technique from computational complexity theory, can provide insights: Oracles provide the ability to compute functionalities in one computational step that otherwise might not be efficiently computable, e.g., provide access to a truly random function or solve any NP-complete problem. These oracles now allow us to replace some parts in the protocol with abstract, idealized primitives that are easier to analyse, e.g., to replace a one-way function with a truly random function. In this thesis, we utilize oracles in two different ways. In the first part, we use oracles to prove lower bounds for cryptographic primitives, i.e., showing that certain assumptions are not sufficient to build this primitive securely. The essential idea here, going back to Impagliazzo and Rudich, is to replace the assumption with an oracle, i.e., replacing a one-way function with a truly random function, and then showing that relative to this oracle, it is impossible to build the primitive. From this impossibility result relative to the oracle, we can now conclude that the primitive cannot be built from the assumption in a black-box way. We use this technique to prove a lower bound on the efficiency of constructing strong from weak one-way functions, to show that we cannot construct collision-resistant hash functions from distributional collision-resistant hash functions in a fully black-box way, and to prove that extremely lossy functions cannot be built from a large class of symmetric primitives in a black-box way. In the second part of this thesis, we use oracles as idealized models that can be used to provide heuristic security arguments for protocols.These idealized models, starting with the random oracle model (short ROM) introduced and defined by Fiat and Shamir as well as Bellare and Rogaway, were motivated by the existence of very efficient cryptographic protocols used in practice, but for which no proof of security existed. Using idealized models, it was now possible to give at least a heuristic security argument for them. In this thesis, we first focus on the common random string model, an idealized model introduced to circumvent impossibility results for non-interactive zero-knowledge proofs. We show how to reuse a single common random string for polynomially many non-interactive statistical zero-knowledge arguments, as well as analyze the relation between different soundness definitions used in literature. In a second result, we introduce an alternative notion for the ROM, the universal random oracle model, which brings this idealized model closer to reality.
Mohammad Madine, Khaled Salah, Raja Jayaraman, Ibrar Yaqoob
In recent years, the healthcare sector has been increasingly challenged in securing patient identities and medical records on blockchain due to rising privacy demands and strict regulatory requirements. Although advanced techniques like self-sovereign identity and zero-knowledge proofs (ZKPs) show promise, these solutions fail to limit unwarranted patient data disclosure effectively. In this paper, we propose a ZKP-based solution that combines STARKs and anonymous credentials to enable anonymous authentication and enhance privacy across both public and private blockchains. Leveraging transparent ZKP schemes and anonymous credentials, our approach ensures unlinkability by preventing the correlation of multiple patient interactions. We present sequence diagrams of real-world interactions, detailed algorithms for on- and off-chain computations, and implement the system on Ethereum and Starknet blockchains. We present a rigorous evaluation of the proposed solution, encompassing smart contract testing on Starknet networks, transaction cost analysis, performance benchmarking, scalability assessment, and static security auditing. The results demonstrate consistent and economically viable transaction costs, millisecond-level execution times for credential issuance, presentation generation, and verification, linear scalability with increasing claim count and size. We compare our solution with state-of-the-art ZKP-based identity systems to demonstrate its superiority. We further discuss its broader applicability beyond healthcare, including domains such as finance, education, and supply chain management. We make the smart contract codes publicly available on GitHub.
Smart contracts automate blockchain transactions but are vulnerable to reentrancy attacks, where an attacker repeatedly calls a function before the contract updates its state, stealing funds. A well-known case is the 2016 DAO exploit, which caused a loss of $60 million.This study investigates methods to protect contracts from such attacks through a literature review, a case study comparing a vulnerable and a fixed contract, and evaluation of analysis tools (Mythril, Slither, Securify, Sereum, BlockWatchdog).The expected results include identifying effective coding patterns (like checks-effects-interactions and reentrancy guards), assessing tool accuracy, and providing secure development guidelines. All experiments will be conducted safely on test networks.