Interoperability of patient files between hospitals continues to present significant obstacles. Health systems frequently utilize central EHR systems that could suffer malfunctions, data breaches, and unauthorized access by third parties. Not only does this jeopardize patient confidentiality, but it also hinders the efficient operations of hospital processes.Blockchain technology is viewed as a prospective remedy for the issue. Blockchain keeps its data differently, allowing users to store data securely and make changes difficult. In this study, we analyze research works published between 2016 and 2023 regarding blockchain-based hospital-to-hospital data exchange.The methodologies differ widely: there are cases where researchers use smart contracts in Ethereum, build a system on Hyperledger Fabric, and deploy IPFS. Moreover, certain studies incorporate encryption methods, machine learning algorithms, and more. In summary, the results show that blockchain allows for improved data protection and transparency while giving patients more control over their personal information. Still, some issues persist, such as scalability, expenses, integration with existing infrastructure, and adherence to GDPR and HIPAA requirements. For future work, more improvements are necessary. For instance, zero-knowledge proofs, cybersecurity measures for new technologies, and using artificial intelligence to audit and validate smart contracts may be promising solutions.
Financial privacy protocols on public blockchains protect transaction linkability but offer no defense when users are physically compelled to reveal their credentials — the "$5 wrench attack." This paper presents a complete solution in two integrated parts. Part I provides the formal cryptographic foundation: dual-nullifier arithmetic selectors within Groth16 zk-SNARK circuits, where path selection between real and decoy funds is computed entirely within the zero-knowledge witness without conditional branching. The R1CS structure is identical for both execution paths (<8% overhead), and the resulting proof is computationally indistinguishable regardless of whether coercion resistance was activated. We formalize peace of mind as a protocol design principle, prove coercion resistance through a four-game sequence-of-games reduction under the Sponge PRF and q-SDH assumptions, and prove withdrawal soundness, double-spend prevention, and front-running resistance. Part II presents ZK-Sentinel V11: a Diamond EIP-2535 architecture with 10 independently upgradeable facets and 104 functions; Stealth Shielded Transfers eliminating temporal correlation at ~60% lower gas cost; 92 privacy pools across 12 tokens on two networks; and a Multi-Tier Compliance Oracle with 4 KYC levels. Indistinguishability is confirmed empirically: a Random Forest classifier trained on 10,000 simulated transactions achieves 50.3% accuracy (AUC-ROC 0.501, p=0.87), consistent with random guessing. To our knowledge, this is the first work providing both a formal coercion resistance proof and a production-scale multi-asset deployment validated across all 12 tokens on two networks.
We prove three impossibility theorems establishing fundamental limits on universal AML compliance in zero-knowledge financial systems. T1 (Completeness Impossibility): no ZK compliance system achieves complete coverage of illicit transactions under rational adversarial behavior. T2 (Oracle Integrity Impossibility): no decentralized oracle network achieves integrity guarantees when state-level adversaries control oracle nodes — cryptographically valid compliance proofs can be semantically false by construction. T3 (Sovereignty Gap Impossibility): no voluntary international compliance framework achieves universal participation when sovereign defection is individually rational. These theorems are not engineering limitations addressable by better cryptography — they are structural properties of the compliance problem under adversarial conditions. Validated empirically against the Tornado Cash OFAC designation (T3) and the Lazarus Group / Ronin Bridge exploit (T2). The theorems characterize the residual attack surface that any compliance architecture must acknowledge and bound rather than claim to eliminate.
<sec> <title>BACKGROUND</title> Self-sovereign identity (SSI) provides a decentralized approach to digital identity management, enabling individuals to control their personal data without reliance on centralized authorities. Blockchain technology offers a tamper-resistant and distributed infrastructure that can support secure and verifiable identity systems. In health care, where identity fragmentation, privacy risks, and interoperability challenges persist, blockchain-enabled SSI (BC-SSI) has been proposed as a potential solution. However, existing research remains heterogeneous, with varying levels of technical maturity and limited evidence of real-world deployment. </sec> <sec> <title>OBJECTIVE</title> This study conducts a scoping review to systematically map BC-SSI applications in health care and to analyze their application domains, development stages, study aims, targeted challenges, and technological infrastructures. In addition, this study aims to identify structural gaps in current research and assess the readiness of BC-SSI systems for clinical deployment. </sec> <sec> <title>METHODS</title> This review followed the PRISMA-ScR (Preferred Reporting Items for Systematic Reviews and Meta-Analyses Extension for Scoping Reviews) methodology. A comprehensive literature search conducted between September 2024 and August 2025 identified 37 peer-reviewed studies that met predefined inclusion criteria. Data were extracted and synthesized using descriptive and thematic analyses across application areas, system maturity, technological components, and reported challenges. </sec> <sec> <title>RESULTS</title> The findings indicate that BC-SSI research in health care remains at an early stage of maturity, with most studies proposing conceptual models or prototype implementations and limited real-world validation. Applications predominantly focus on identity verification, credential management, and privacy-preserving data exchange across domains such as electronic health records, mobile health, and access control systems. Commonly used technologies include decentralized identifiers, verifiable credentials, smart contracts, and privacy-enhancing mechanisms such as zero-knowledge proofs and selective disclosure. Despite rapid technical development, persistent challenges include interoperability limitations, governance gaps, usability concerns, and insufficient integration with health care infrastructures. Notably, a structural gap was identified between technological capability and system-level readiness for clinical deployment. </sec> <sec> <title>CONCLUSIONS</title> BC-SSI technologies demonstrate potential for enabling secure, interoperable, and patient-centric identity management in health care. However, current research is predominantly technology-driven and lacks sufficient system-level validation. This study highlights the need for integrated architectural approaches, governance frameworks, and real-world evaluation to bridge the gap between conceptual innovation and clinical implementation. Advancing BC-SSI toward health care adoption will require coordinated progress across technical, organizational, and regulatory dimensions. </sec>
The modular invariance and automorphism group rigidity of vertex operatoralgebras provide a profound mathematical foundation for constructing novel postquantum cryptographic systems. However, a significant theoretical and engineeringgap exists between mathematical theorems and deployable cryptosystems. Thispaper does not propose new cryptographic protocols but rather systematicallyexamines the core challenges encountered in engineering vertex operator algebracryptography: the discrete selection of parameter spaces and their quantitativerelationship with security strength, the computational resource requirements ofcandidate algebraic families (lattice vertex operator algebras, WZW models, andmoonshine vertex operator algebras), the assessment of security boundaries underquantum attack models, and the practical overhead of auxiliary mechanisms suchas zero-knowledge proofs. The objective is to provide a clear problem inventoryand a feasibility analysis framework for future research, rather than to claim anyimmediately usable security parameters. The article concludes by summarizing thecurrent technology readiness levels and identifying the key breakthroughs requiredto advance from a theoretical framework toward a practical system.
Digital signature schemes derived from non-interactive zero-knowledge (NIZK) proofs are rapidly gaining prominence within post-quantum cryptography. CROSS is a promising new code-based post-quantum digital signature scheme based on the NIZK framework. It is currently in the second round of the NIST’s additional call for standardization for post-quantum digital signatures. However, CROSS’s reference implementation has a substantially large memory footprint. This makes its deployment on resource-constrained platforms prohibitively difficult.In particular, we identified the most memory-intensive areas such as Merkle and GGM tree structures, and zero-knowledge proof commitment generation. We propose several novel algorithms and implementation strategies to reduce the memory requirement of these components. Apart from these, we also propose several memory optimization techniques, such as just-in-time hashing and execution flow analysis. As a result, our implementation reduces the memory footprint of Key Generation, Signature Generation, and Verification of the CROSS reference code by as much as 95%, 92%, and 85%, respectively. This results in a suite of implementations in which all variants are under 128kB (for all security levels of KeyGen/Sign/Verify) and six variants under 32kB. Our memory optimization techniques are not specific to CROSS, but can be applied to other NIZK-based signature schemes.Regarding efficiency, matrix multiplications are crucial to the performance of CROSS. We show how the Digital Signal Processing (DSP) instructions on ARM Cortex-M4, specifically packing and multiplying, can be utilized to efficiently implement matrix operations over finite fields. The DSP optimizations combined with the memory reductions improve the efficiency of CROSS by up to 32% and 33% in Signature Generation and Verification respectively.
Industrial operational technology systems are becoming more intelligent and interconnected, requiring remote maintenance and multiparty collaboration. While traditional approaches improve efficiency, they introduce risks like data leakage and unauthorized operations. Existing access control schemes struggle with compliance verification and auditing while ensuring privacy. A novel access control scheme was proposed that combines zero-knowledge proof with the publicly verifiable covert security model. The scheme features a dual-layer verification mechanism: a basic layer using zero-knowledge proof to protect identities and permissions during remote maintenance and an enhanced layer for high-risk operations that uses oblivious transfer and digital signatures to detect malicious behavior and generate cheating certificates. Security analysis showed the scheme ensures privacy, access legitimacy, and non-repudiation. Experiments demonstrated the scheme had faster proof generation and verification compared to existing methods with effective malicious behavior detection and accountability.
A novel blockchain-based smart contract framework is proposed and designed to mitigate financial product fraud by enhancing transparency, auditability, and trust in advisory processes. The framework introduces a unique dual-contract architecture that combines product and authorization smart contracts, along with a challenge-response verification protocol that ensures both product authenticity and advisor legitimacy. The system is implemented and tested on the Ethereum blockchain, demonstrating operational feasibility through real-world transaction simulations and a corresponding gas cost analysis. By leveraging immutability, the framework preserves data integrity, while cryptographic signatures enable privacy protection without exposing sensitive data on-chain. It is designed to support multi-institutional environments, allowing various financial institutions to issue products and authorize advisors under a unified, fraud-resistant platform. Experimental results confirm the system’s effectiveness in preventing common fraud scenarios, while maintaining low transaction costs and high security.
Blockchain is a decentralised and distributed ledger technology that enables multiple participants to collectively maintain a secure and tamper-resistant record of transactions without relying on trusted central authorities. It has several potential features, including decentralisation, immutability, transparency and security. Beyond its original use in cryptocurrencies, blockchain has facilitated a diverse range of applications, including decentralised finance, supply chain tracking, digital identity management, secure voting systems and decentralised autonomous organisations, where transparency, trustlessness and data integrity are critical. Structurally speaking, a blockchain consists of an ordered sequence of blocks, each containing a set of validated transactions. Every block incorporates a cryptographic hash of its previous block, linking them into an immutable chain that maintains chronological ordering and prevents tampering. At its foundation, a blockchain relies on the consensus mechanism that ensures all untrusted participants agree on a consistent ledger state, despite network latency or malicious behaviour. Up to now, widely adopted consensus algorithms include proof-of-work (PoW), which relies on computationally intensive puzzles, and proof-of-stake (PoS), which utilises economic incentives based on stake ownership. Unlike PoW, PoS consumes less energy, achieves faster block finalisation with lower latency and lowers participation barriers, enhancing efficiency, scalability and decentralisation without compromising security.Digital signatures are fundamental cryptographic primitives essential for establishing trust and ensuring security in digital communications. By using a secret key to generate signatures on given messages, anyone who knows the corresponding public key can check the validity of signature candidates. This cryptographic process provides critical guarantees such as authentication, data integrity and non-repudiation, making them integral to secure communication and a wide range of cryptographic protocols. In PoS blockchain protocols, digital signatures play a crucial role not only in authenticating transactions but also in validating the participation of stakeholders in consensus processes, such as block proposals and block attestations. Advanced signature schemes, including forwardsecure signatures or puncturable signatures, are often employed to prevent long-range attacks caused by secret key leakage, preserving the immutability of PoS blockchain protocols. Furthermore, threshold or weighted threshold signatures are frequently deployed in PoS-based protocols to aggregate multiple block attestations into a single compact one efficiently, enhancing scalability while maintaining robust security guarantees.This thesis focuses on advanced digital signature schemes deployed in proof-of-stake blockchain protocols, with particular emphasis on puncturable signatures and weighted threshold signatures. To be more specific, the main contributions of this thesis are outlined as follows.First, we focus on puncturable signatures and propose the first generic construction derived from identity-based signatures by treating identities as to-be-punctured prefixes. Based on this framework, we give concrete puncturable signature instantiations over bilinear maps, lattices and multivariate polynomials, respectively. More specifically, the pairing-based instantiation is proven secure based on the computational Diffie-Hellman (CDH) assumption in the standard model. The lattice-based instantiation achieves provable security under the short integer solution (SIS) assumption in the random oracle model. The multivariate-based instantiation is analysed against some best-known attacks in multivariate public key cryptography. All of the proposed schemes support efficient puncture operations, while the lattice-based and multivariate-based ones additionally enjoy post-quantum security.Second, we adopt a different approach to constructing puncturable signatures supporting compact secret keys that serve as an effective mitigation against long-range attacks caused by secret key leakage in PoS blockchains. Specifically, we propose a new generic construction of puncturable signatures from delegated (key-policy) constrained signatures. Such a framework is inspired by an observation that matching between messages and constraints can be converted to equality tests between prefixes of to-be-signed messages and punctured prefixes. The key delegation property of (key-policy) constrained signatures enables repeated key puncture operations. Building on our framework, we give a concrete lattice-based instantiation that is proven secure based on the SIS assumption in the standard model. Our proposed scheme features small secret key sizes, particularly for the initial secret key, which is beneficial for users to join PoS blockchains without requiring a significant commitment in the initial phase.Third, we revisit the notion of puncturable signatures and find their vulnerability in mitigating long-range attacks caused by secret key leakage in PoS blockchains. Despite their key evolving property, compromising previous secret keys enable adversaries to forge branches in PoS blockchains, bypassing the security guarantees provided by puncturable signatures. It is essential to invalidate previous secret keys, regardless of whether they have been securely deleted. Therefore, we integrate key puncture and signing operations into a unified Sign-and-Pun algorithm. By publishing punctured prefixes and providing additional proofs, our strengthened puncturable signatures ensure that no malicious signers can generate valid signatures using previous secret keys. Furthermore, we propose a concrete lattice-based construction that is provably secure under the SIS assumption in the standard model.Finally, we focus on weighted threshold signatures for block attestations in PoS blockchain protocols, where validators are assigned different weights to reflect their varying impacts on consensus decisions. Specifically, we present the first weighted threshold signature scheme over lattices, which is a combination of multi-signature and non-interactive inner product arguments. In our proposed scheme, the weights of signers are public and work as a separate checking condition in threshold signature verification. We show that our scheme is provably secure under the module short integer solution (MSIS) assumption in the random oracle model. Furthermore, we demonstrate how to integrate our scheme into PoS blockchains for block attestation. Moreover, we implement our scheme in the C programming language and present an experimental evaluation of its practical efficiency.
Introduction: Intelligent room systems are experiencing a surge in demand within the Healthcare 4.0 ecosystem. The integration of Federated Learning (FL) and Data-Centric AI has led to substantial enhancements in the predictive capabilities of machine learning models while maintaining data privacy. However, centralized aggregation in FL remains a single point of failure and is vulnerable to poisoning attacks. Methods: This paper presents a novel, privacy-preserving architecture for Ambient Intelligence (AmI) that integrates Distributed Ledger Technology (DLT). Results: We explicitly note that while DLT does not preemptively prevent the generation of poisoned gradients, it provides an immutable, cryptographically secure audit trail. This ensures the trustworthiness and traceability of model updates for post-hoc detection, strict accountability, and targeted model rollbacks. Discussion: By fusing Data-Centric AI for quality assurance with a Blockchain-enabled FL framework, we propose a scalable, low-cost solution for real-time patient monitoring in diverse economic settings.
Collins Izuchukwu Okafor, Love Allen Chijioke Ahakonye, Dong‐Seong Kim, Jae Min Lee
Vehicular-to-Everything (V2X) communications promise unprecedented safety and efficiency gains but remain vulnerable to confidentiality breaches such as eavesdropping, traffic analysis, and man-in-the-middle attacks. We propose ConfidSPEC-V2X, a focused hybrid framework that integrates continuous-variable quantum key distribution (CV-QKD), a multi-agent deep reinforcement learning (DRL), and an Ethereum-based permissioned blockchainPureChainpublic-key infrastructure (PKI) to deliver information-theoretic secrecy, dynamic traffic obfuscation, and tamper-proof key management. In the quantum module, CV-QKD transceivers embedded in On-Board Units (OBUs) and Roadside Units (RSUs) establish symmetric keys resilient to passive interception and capable of immediate eavesdropping detection. The Artificial Intelligence (AI) module employs multi-agent DRL agents at RSUs to learn optimal dummy-traffic injection policies that obfuscate real V2X message patterns against statistical inference. The blockchain module leverages PureChain smart contracts to register, rotate, and timestamp vehicle public keys, ensuring that any man-in-the-middle attempt to forge or replay keys is invalidated. We implement and evaluate ConfidSPEC-V2X within an OMNeT++/Veins simulation under realistic urban mobility scenarios, measuring the quantum bit error rate, key generation throughput, obfuscation entropy, and key management latency. Results demonstrate that our framework achieves robust confidentiality protection with minimal performance overhead.
In the classic model, data integrity assumes a simple sender-receiver channel where threats are limited and verifications are straightforward. However, the modern Internet has reshaped this paradigm. In an era of viral misinformation, encrypted messaging, and decentralized finance, integrity is no longer about just who sent the data, but what it really means and whether it can be trusted. For instance, can we verify the authenticity of a direct message screenshot? Is Signal's end-to-end encryption truly end-to-end when a central server distributes users' keys? Can decentralized protocols, which have attracted four trillions in capital, sustain trust under attacks that wipe out millions?In response, we present a modern perspective on data integrity across diverse systems, arguing for the need of comprehensive innovations from theory to practice along three axes: cryptographic foundation in which we borrow ideas from theoretical research and develop interesting cryptographic tools, protocol design in which we find and achieve novel application goals, and empirical security analysis in which we critically evaluate deployed systems to understand their strengths and exploit their blind spots.To ground these ideas, we discuss three cases: Cauchyproofs as a batch-updatable vector commitment, an analysis of proxying in TLS oracles revealing subtleties in AEAD context unforgeability, and attacks and improvements on the Tor directory protocol. These case studies illustrate both the fragility and opportunity in today's integrity landscape, and how an integrated approach can help guide us forward.
This paper introduces ZKAP (Zero-Knowledge Audit Protocol), a cryptographic protocol in which a machine-learning inference is coupled to a zero-knowledge proof of constraint satisfaction in such a way that the output of the inference cannot be released on any observable channel unless the proof verifies. The protocol rests on two principal technical contributions: The Certified Stack — a composite object that cryptographically binds the model weights, a mandatory bit-integrity policy (integer quantisation), the inference runtime stack and the hardware configuration under a single commitment (RootHash), which is included as a public input to every proof produced by the system. Prove-before-output enforcement — a family of four embodiments (hardware output gate, trusted-execution-environment release path, silicon-level embodiment, syscall-intercepting software runtime) in which the output of the inference is physically blocked from leaving the system until the accompanying proof has verified against the Certified Stack commitment and against a constraint set signed by an external authority. Three supporting mechanisms are described: authority-signed formal constraints with a five-type taxonomy, a per-inference hash chain with external anchoring, and a three-party cryptographic separation of duties. The paper further discusses practical relaxations of the strict release semantics for real-time workloads. A soundness theorem is stated against a polynomial-time adversary controlling the operator of the inference, and regulatory implications for high-risk AI systems under Regulation (EU) 2024/1689 (Artificial Intelligence Act) are discussed. Priority declaration. The inventive mechanisms described in this paper are the subject of Bulgarian patent applications BG/P/2026/114317 (filed 30 March 2026) and PTBG202600000316742 (filed 12 April 2026). This preprint establishes the academic priority of the author, as of the date of the deposit timestamp, over the specific technical constructions described in Sections 3 and 4 of the paper. Access note. This deposit is under embargo until 31 March 2027. During the embargo, metadata (title, abstract, author, keywords, references) are publicly visible; the full text is not publicly accessible. The embargo date coincides with the Paris Convention priority deadline of the underlying Bulgarian patent application BG/P/2026/114317. The DOI assigned at deposit time serves as a timestamp for academic priority purposes, independent of the file's accessibility.
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Emergency vehicle authentication in vehicular ad hoc networks must satisfy strict latency, privacy, and trust constraints. Existing Public Key Infrastructure- and Conditional Privacy-Preserving Authentication-based schemes incur substantial overhead from certificate management and expensive per-hop verification, making them unsuitable for real-time emergency scenarios. We propose a lightweight zero-knowledge- and blockchain-assisted authentication scheme that eliminates certificates, pseudonym pools, and the requirement for online interaction with a trusted authority during the authentication phase. The Certificate Authority (CA) is involved only during offline initialization stages (vehicle enrollment and Merkle tree construction); once provisioning is complete, the runtime authentication process operates without any online CA interaction. Each emergency vehicle registers one-time hash commitments on-chain after proving membership in a category-specific Merkle tree, and authenticates messages by broadcasting a hash along with a zero-knowledge proof of preimage knowledge. Roadside units verify the proof and consult the on-chain state to enforce single-use semantics, creating a tamper-resistant audit trail. Evaluation using the Veins framework (OMNeT++/SUMO) demonstrated a constant 288-byte authenticated payload, millisecond-level end-to-end delay independent of hop count, and stable blockchain processing under sustained load.
The transition from isolated distributed ledgers to a unified “Internet of Value” is hindered by the lack of efficient, verifiable, and privacy-preserving cross-chain data retrieval mechanisms. While asset bridging has matured, generalized data indexing remains a critical bottleneck, constrained by the semantic gap between heterogeneous storage layouts and the prohibitive verification tax of cryptographic proofs. In this paper, we present HyperCross, a novel semantic-aware zero-knowledge indexing framework designed to bridge this divide. We first formalize the heterogeneous cross-chain storage optimization problem (HCCSOP) and prove its NP-completeness. To tackle this, HyperCross employs a synergistic tri-layered architecture. At the semantic layer, we introduce a unified data abstraction (UDA) that leverages category-theoretic functors and schema morphisms to ensure mathematically rigorous state mapping for both simple assets and complex smart contract logic. At the indexing layer, a zero-knowledge learning index (ZKLI) shifts prediction intelligence to the client side, integrating zk-SNARKs with silent oblivious transfer to achieve constant-time verification (O(1)) while concealing access patterns. Finally, a multi-level cache (MLC) utilizes predictive prefetching with Δ-bounded staleness to mask network latency. Extensive evaluations demonstrate that HyperCross reduces query latency by 2.4× and storage overhead by 40% compared to state-of-the-art baselines, establishing a scalable foundation for data-intensive inter-chain applications.
Zero-knowledge proof (ZKP) provers remain costly because multi-scalar multiplication (MSM) and number-theoretic transforms (NTTs) dominate runtime as they need significant computation. AI ASICs such as TPUs provide massive matrix throughput and SotA energy efficiency. We present MORPH, the first framework that reformulates ZKP kernels to match AI-ASIC execution. We introduce Big-T complexity, a hardware-aware complexity model that exposes heterogeneous bottlenecks and layout-transformation costs ignored by Big-O. Guided by this analysis, (1) at arithmetic level, MORPH develops an MXU-centric extended-RNS lazy reduction that converts high-precision modular arithmetic into dense low-precision GEMMs, eliminating all carry chains, and (2) at dataflow level, MORPH constructs a unified-sharding layout-stationary TPU Pippenger MSM and optimized 3/5-step NTT that avoid on-TPU shuffles to minimize costly memory reorganization. Implemented in JAX, MORPH enables TPUv6e8 to achieve up-to 10x higher throughput on NTT and comparable throughput on MSM than GZKP. Our code: https://github.com/EfficientPPML/MORPH.
DilithiumBar Architecture DilithiumBar is a high-performance, post-quantum (PQ) blockchain protocol engineered to withstand the cryptographic threats posed by future quantum computing. By replacing standard ECDSA signatures with the CRYSTALS-Dilithium5 lattice-based scheme, the system ensures long-term security without compromising operational efficiency. The protocol integrates a sophisticated suite of modern blockchain innovations: Post-Quantum Security: Native implementation of NIST-standardized lattice cryptography to secure transactions and state transitions. High-Finality Consensus: A Byzantine Fault Tolerant (BFT) mechanism that provides deterministic 10-second finality, significantly faster than traditional Proof-of-Work systems. Advanced State Management: Utilizes a Merkle-Patricia Trie for verifiable state tracking and atomic database operations to ensure data integrity. Dynamic Economics: An EIP-1559 inspired fee market that stabilizes transaction costs and optimizes network throughput. While the protocol acknowledges the increased bandwidth and storage requirements typical of post-quantum primitives, it balances these trade-offs through an optimized architecture designed for the next era of decentralized finance.
The Distributed Medical Report Management System using Blockchain Technology is designed to revolutionize the management and sharing of medical reports by integrating blockchain technology, specifically targeting data security and patient privacy.This system enhances the protection of Electronic Health Records (EHR) through sophisticated cryptographic methods and decentralized storage solutions.It consists of four core modules-Hospital, Doctor, Patient, and Receptionist-each tailored to manage specific healthcare tasks.The Hospital Module enables secure management of patient records and administrative tasks, creating a transparent and unchangeable ledger that boosts data integrity and builds trust.The Doctor Mod-ule allows healthcare professionals to securely access and update patient records, with cryptographic safeguards ensuring that only authorized users can see or alter sensitive information, significantly reducing the risk of data breaches.The Patient Module empowers individuals by providing direct access to their medical records, allowing them to monitor their health history and control who can view their data.The Receptionist Module streamlines administrative functions, such as appointment scheduling, while securely logging all interactions on the blockchain.By replacing traditional paper-based systems, this blockchain-centric approach offers a more secure, efficient, and user-friendly method for managing sensitive patient data.Advatages include enhanced security through blockchain protection, decentralized storage minimizing risks of data loss, improved accessibility for authorized healthcare providers, and increased patient control over their health information.Ultimately, the Distributed Medical Report Management System demonstrates the transforma-tive potential of blockchain technology in creating a secure framework for managing patient records, addressing challenges in healthcare data management, and paving the way for a more efficient healthcare system.
This repository/dataset presents the Matrix Cryptographic Tree (MCT), a novel cryptographic primitive based on the special linear group SL(2, \mathbb{Z}). Unlike traditional hash-based Merkle Trees, MCT is fully reversible and structure-preserving, allowing for unique algebraic verification without information loss. The core of this research is the integration of Unified Zero-Knowledge Proofs (ZKP). MCT enables advanced privacy-preserving operations, such as proving data similarity (L1 norm distance), prefix/suffix matching, and existence proofs, all without revealing the underlying data.
Rabib Jahin Ibn Momin, Ahmed Mahir Sultan Rumi, Rezwana Reaz
Academic examination systems worldwide continue to rely on centralised, opaque record-keeping that is often vulnerable to credential forgery, result tampering, examiner bias, and the absence of transparent re-evaluation pathways. Existing blockchain-based approaches in education focus predominantly on post-hoc certificate storage or online-only examination portals, leaving the complete onsite examination lifecycle, from conducting exams through scrutiny, largely unaddressed. This paper proposes ParikkhaChain, a blockchain-based framework that covers the entire examination lifecycle of an onsite examination system with three distinguishing contributions: (i) anonymous script evaluation through cryptographic hashing of answer scripts before examiner access, thereby eliminating identity-based bias; (ii) a transparent evaluation and scrutiny workflow backed by an immutable on-chain audit trail that records every mark submission and grade revision; and (iii) inclusion of privacy-preserving verification using zero-knowledge proofs and off-chain storage mechanisms. The system is architected around four Solidity smart contracts deployed on the Ethereum blockchain. The proposed architecture is the first initiative to our knowledge to support physical examination process, anonymous marking, and re-evaluation transparency. We successfully simulate full exam cycles of an onsite exam to grade-sheet generation using a working prototype on a large scale of 100 courses and hundreds of teachers and students. The experimental results show that the system can manage online examinations of hundreds of courses, students and faculties efficiently with great throughput, low storage, and transaction cost. Our codebase is available in open source form at https://github.com/AhmedRumi/CSE6608-ParikkhaChain
Blockchain-Driven Healthcare Platform with Access-Controlled Record Management is a decentralized application designed to enhance the security, privacy, and accessibility of medical records. Traditional healthcare systems rely on centralized storage, making sensitive patient data vulnerable to breaches, manipulation, and unauthorized access. This project utilizes blockchain technology to provide a secure and tamper-proof environment for storing and managing healthcare data. Smart contracts are implemented to enforce access control, allowing patients to grant or revoke permission to doctors and healthcare providers. Medical records are securely stored using decentralized storage mechanisms, while blockchain maintains immutable references to ensure data integrity. The platform integrates Web3 technologies for secure user authentication and seamless interaction with the blockchain network. By eliminating intermediaries, the system improves transparency and trust among stakeholders. This solution demonstrates an efficient approach to managing healthcare data, ensuring confidentiality, integrity, and availability while addressing the limitations of traditional healthcare record systems in a modern, digital environment.
ABSTRACT E-voting in polarized contexts requires a strict balance between public verifiability, ballot secrecy, andcoercion resistance. Traditional centralized systems lack transparency, while fully decentralized modelsface scalability and privacy issues. This paper proposes a hybrid architecture compliant withOSCE/ODIHR standards [1] for low-trust environments. The protocol decouples identity from voting anoff-chain Oracle manages authorization via cryptographic tokens, while the Waves DLT acts as animmutable bulletinboard.Utilizinghomomorphicencryption[2],Zero-KnowledgeRangeProofs(ZKRP) [3],and Distributed Key Generation (DKG) [4], the system ensures End-to-End Verifiability (E2E) bydelegating tallying to auditable scripts. Finally, the study examines model limitations, specificallyregarding endpoint vulnerabilities and physical constraints on coercion resistance. KEYWORDS E-Voting, Distributed Ledger Technology, Homomorphic Encryption, End-to-End Verifiability, ZeroKnowledge Proofs PDF LINK: https://ijcionline.com/paper/15/15226ijci01.pdf VOLUME LINK: https://airccse.org/journal/ijci/Current2026.html MORE DETAILS: https://airccse.org/journal/ijci/index.html
We present DSKAG-IT-SIG, a family of post-quantum transaction signature schemes that achieve computational existential unforgeability under adaptive chosen-message attack, built on the DSKAG deterministic key-derivation layer. The construction derives per-transaction MAC keys through DSKAG, a deterministic symmetric key agreement protocol requiring no key transmission, no handshake, and no public key infrastructure. We prove (Theorem 1) that for an adversary making q adaptive chosen-message queries, existential forgery advantage in standard mode is at most q * 2^{-128} plus the PRF distinguishing advantage of HMAC-SHA256, reducing to the pseudorandomness of DSKAG-derived keys and the PRF security of HMAC-SHA256 under a uniform key; the ideal-cipher-model analysis gives the same q * 2^{-128} bound in idealized form. We prove (Theorem 2) that cross-domain forgery advantage is at most 2^{-128} + epsilon_iso, reducing to the key-separation properties of DSKAG across policy domains. The construction is computationally secure and is not unconditionally secure. DSKAG key derivation is built on HKDF-SHA512 (RFC 5869) over HMAC and SHA-512, and the shared base is established once via FIPS 203 ML-KEM, so security reduces throughout to standard FIPS-based symmetric and hash primitives. The scheme's post-quantum security rests on symmetric and hash hardness for authentication and on lattice hardness for the one-time base alone: the construction presents no integer-factorization or discrete-logarithm structure, so Shor's algorithm has no target and does not apply, and the operative quantum attack is Grover search, which yields at most a quadratic speedup against the 256-bit HMAC-SHA256, SHA-2, and SHA-3 primitives and preserves a 128-bit quantum security level. Because buffer uniqueness derives from tx_seq monotonicity rather than hash collision resistance, the security argument does not depend on the collision property, the hash property most weakened by quantum search. Standard-mode signatures are 30 bytes, a 97.8% reduction versus Falcon-512 (666 bytes) and compatible with ISO 20022 SWIFT message fields without re-engineering. The NexusKey composite policy digest binds asset class, jurisdiction, KYC level, and chain identity into the key derivation path; policy bypass is cryptographically equivalent to key forgery. A four-layer UltraHonk zero-knowledge proof system (143,802 gates, no trusted setup, 16 KB proof) verifies policy compliance wherever policy is enforced, off-chain in governance, cloud, and payment-processing deployments, and, where permissionless public auditability is required, on-chain; the on-chain Solidity verifier is deployed on Ethereum Sepolia and Arbitrum Sepolia. Version 2.3. 18 pages, 8 tables. Changes from v2.2: concrete finite bounds replacing generic negl(lambda) in Properties 1 and 2; buffer uniqueness derived from tx_seq monotonicity (no SHA3 collision resistance dependency); explicit ideal cipher model and standard model dual framing for HMAC analysis; formal separation of empirical and theoretical claims.
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Cryptography and Data Security
Cryptographic Implementations and Security
Physical Unclonable Functions (PUFs) and Hardware Security