Russell W. F. Lai, Monisha Swarnakar, Ivy K. Y. Woo
The Learning with Errors (LWE) problem asks to distinguish noisy samples s^T A + e^T mod q from uniformly random values given the random matrix A. In this work, we show that a variant called Leaky LWE, where the distinguisher receives additionally noisy leakages (s^T, e^T) L + f^T of the LWE secret s and error e for low-norm matrix L chosen adaptively by the distinguisher after seeing A, is not easier than the standard LWE of the same dimensions up to polynomial losses in the noise level and the modulus. More generally, we show that the Leaky LWE problem is hard even if the public matrix A is structured and/or hinted and if the non-leaky parts of the secret and error do not follow Gaussian distributions, as long as the corresponding LWE problem without leakage is hard. Our reduction from LWE to Leaky LWE unifies and extends prior results on the Error-Leakage LWE problem [Döttling-Kolonelos-Lai-Lin-Malavolta-Rahimi, EUROCRYPT'23], where L only acts on the error e and the Hint-MLWE problem [Kim-Lee-Seo-Song, CRYPTO'23], where L is restricted to concatenations of random Gaussian scalar matrices not controlled by the distinguisher. Previously, the Hint-MLWE and Error-Leakage LWE assumptions were used as computational replacements of the statistical noise flooding technique in security proofs which led to improved parameters in lattice-based cryptographic constructions such as zero-knowledge proofs, threshold signatures and registration-based encryption. We provide lemmas which abstract out such computational arguments based on Leaky LWE.
An anonymous credential (AC) system with partial disclosure allows users to prove possession of a credential issued by an issuer while selectively disclosing a subset of their attributes to a verifier in a privacy-preserving manner. In keyed-verification AC (KVAC) systems, the issuer and verifier share a secret key. Existing KVAC schemes rely on computationally expensive zero-knowledge proofs during credential presentation, with the presentation size growing linearly with the number of attributes. In this work, we propose two highly efficient KVAC constructions that eliminate the need for zero-knowledge proofs during the credential presentation and achieve constant-size presentations. Our first construction adapts the approach of Fuchsbauer, Hanser and Slamanig (JoC'19), which achieved constant-size credential presentation in a publicly verifiable setting using their proposed structure-preserving signatures on equivalence classes (SPS-EQ) and set commitment schemes, to the KVAC setting. We introduce structure-preserving message authentication codes on equivalence classes (SP-MAC-EQ) and designated-verifier set commitments (DVSC), resulting in a KVAC system with constant-size credentials (2 group elements) and presentations (5 group elements). To avoid the bilinear groups and pairing operations required by SP-MAC-EQ, our second construction uses a homomorphic MAC with a simplified DVSC. While this sacrifices constant-size credentials (n+2 group elements, where n is the number of attributes), it retains constant-size presentations (2 group elements) in a pairingless setting. We formally prove the security of both constructions and provide open-source implementation results demonstrating their practicality. We extensively benchmarked our KVAC protocols and, additionally, bechmarked the efficiency of our SP-MAC-EQ scheme against the original SPS-EQ scheme, showcasing significant performance improvements.
In this paper, we show for the first time it is practical to privately delegate proof generation of zkSNARKs to a single server for computations of up to 2^20 R1CS constraints. We achieve this by computing zkSNARK proof generation over homomorphic ciphertexts, an approach we call blind zkSNARKs. We formalize the concept of blind proofs, analyze their cryptographic properties and show that the resulting blind zkSNARKs remain sound when compiled using BCS compilation. Our work follows the framework proposed by Garg et al. (Crypto'24) and improves the instantiation presented by Aranha et al. (Asiacrypt'24), which implements only the FRI subprotocol. By delegating proof generation, we are able to reduce client computation time from 10 minutes to mere seconds, while server computation time remains limited to 20 minutes. We also propose a practical construction for vCOED supporting constraint sizes four orders of magnitude larger than the current state-of-the-art verifiable FHE-based approaches. These results are achieved by optimizing Fractal for the GBFV homomorphic encryption scheme, including a novel method for making homomorphic NTT evaluation packing-friendly by computing it in two dimensions. Furthermore, we make the proofs publicly verifiable by appending a zero-knowledge Proof of Decryption (PoD). We propose a new construction for PoDs optimized for low proof generation time, exploiting modulus and ring switching in GBFV and using the Schwartz-Zippel lemma for proof batching; these techniques might be of independent interest. Finally, we implement the latter protocol in C and report on execution time and proof sizes.
The Metaverse has evolved into a transformative ecosystem, merging virtual and physical realities with consumer electronics and IoT to enable immersive experiences. However, vulnerabilities like avatar impersonation, identity theft, and Sybil attacks, compounded by centralized intermediaries, underscore the urgent need for decentralized solutions to enhance interoperability, security, and user-centricity. This paper proposes a smart contract-based authentication scheme for the Metaverse, leveraging Web 3.0 technologies to achieve decentralization and address existing limitations. The scheme ensures user-server and avatar-avatar authentication while maintaining anonymity, unlinkability, and incorporating an avatar revocation mechanism. Security validation is conducted using the informal analysis, and smart contract implementation. The system’s operational efficiency is benchmarked against existing solutions using metrics such as computational, bandwidth, and communication costs. Results demonstrate the proposed scheme’s superior performance in reducing computational and communication overhead, making it highly suitable for Metaverse applications. Additionally, the smart contract is implemented on the Ethereum test network, confirming its feasibility and showcasing an acceptable cost for blockchain consumption.
Ahmed Osama Daoud, Ratan Lal, Ahmed Gouda Mohamed, Mayar Mohamed · 5 authors
The Egyptian construction sector faces persistent challenges, including inefficiencies, delays, cost overruns, and contractual disputes, often due to fragmented workflows, manual documentation, and limited technological integration. This study investigates the potential of blockchain technology and smart contracts to improve transparency, automate contract enforcement, and enhance risk management within the sector. A conceptual framework was developed and tested using Partial Least Squares Structural Equation Modeling (PLS-SEM) based on data from 92 professionals across the construction industry. The findings reveal that key motivators for adoption include the willingness of clients and contractors (β = 0.809), clarity in responsibility and risk allocation (β = 0.772), and user-friendly contract interfaces (β = 0.747). Conversely, significant challenges include legal enforceability concerns (β = 0.855), broader legal ambiguities (β = 0.805), and market hesitation (β = 0.672). The study highlights the mediating role of these challenges and emphasizes the need for regulatory reform, stakeholder engagement, and capacity building. The proposed framework offers practical guidance for policymakers, industry leaders, and technology providers aiming to drive blockchain adoption in Egypt’s construction sector and similar emerging markets.
Bitcoin is one of the famous cryptocurrencies in the world. It is a permissionless blockchain, and all transactions are stored in a public decentralized ledger. In its security design, Bitcoin utilizes various cryptographic primitives, such as hash functions and signature schemes. In the current version of Bitcoin, the Elliptic Curve Digital Signature Algorithm (ECDSA) is employed, which is not considered post-quantum secure due to the Shor's algorithm. Since December 2016, the National Institute of Standards and Technology (NIST) initiated a process to standardize certain post-quantum cryptographic primitives, including key encapsulation mechanisms (KEMs), public key encryption (PKE), and digital signature schemes. Dilithium, a lattice-based digital signature scheme, emerged as one of the winners of this competition and is recently standardized as ML-DSA (FIPS 204). In this work, we analyze the potential replacement of the ECDSA signature, the current signature in Bitcoin, with Dilithium, which is a post-quantum digital signature. This replacement will have a significant impact on many protocols within the Bitcoin ecosystem. The ECDSA algorithms are not only utilized for transaction signing and verification but also in wallet management. Bitcoin operates on a pseudonymous system rather than complete anonymity. To enhance privacy protection, the Bitcoin community has adopted a special type of (hierarchical) deterministic wallet as outlined in Bitcoin Improvement Proposal 32 (BIP32). We have constructed deterministic wallets by first designing DilithiumRK, a signature scheme with rerandomizable keys from Dilithium. Subsequently, we conducted a thorough security analysis and successful implementation of DilithiumRK.
Issa Binda, Ahonankpon Hubert Frédéric Gbaguidi, Toussaint Vigninou
After a dozen years of implementing decentralization in Benin, local development actions remain timid because of the weak mobilization of financial resources. The overall objective of this research is to contribute to a better knowledge of the strategies for mobilizing own resources for the local development of the Municipality of Ouaké. The methodological approach adopted consisted in the collection of quantitative and qualitative data. These are demographic data, planimetric data and socio-economic data from population surveys. These various data collected from 91 people were analyzed and processed in order to arrive at the results. The results obtained show that the construction of socio-community infrastructures was made thanks to the financial and technical support of development partners and then the FADEC fund. The State, the Town Hall, the projects and the development associations of the municipality have financed the construction of several economic, socio-community infrastructures and other local development initiatives. The local communities have also participated in the development thanks to individual actions and the resources mobilized within the cooperative groupings and the local workforce. However, it should be noted a low rate of mobilization of budgetary resources, the average of which is 41% from 2018 to 2022. The average recovery rate of the 22 types of resources available to the municipality of Ouaké is below 50%. This shows that the actors have difficulties in mobilizing the municipality's own resources. It was thus devoted to these two lines only, for the nine years considered, an amount of 376,967,075 CFA francs out of a total operating expenditure of 555,625,774 CFA francs, i.e. more than 67.84% of operating expenses. From 2014 to 2022, four main investment lines absorb 851,979,521 CFA francs out of the total estimated investments of 1,179,157,828 CFA francs, or more than 72.25% of all investments made.
Leela V, Kanishka K, Kaviyasri S, Guru Dharshan K · 6 authors
Protecting privacy, availability, and security of Electronic Health Records (EHRs) is of utmost importance in the modern digital health industry. Traditional centralized storage system has been under increasing security threats like illegal access, data tampering, cyber-attack and single point of failure. To address these problems, we present in this work a new blockchain-based system which combines Token-Based Authentication and Permissioned Pure Proof-of-Stake (PPoS) consensus model. The architecture authenticates the identity of participants using Decentralized Identifiers (DIDs) and generates cryptographic tokens providing limited access to EHRs that expire over time. These tokens, together with encrypted metadata and access logs are written on a permissioned block chain to provide transparency, traceability and finegrained access control. For data privacy concern, the real health record is off-chained saved with encryption by the ChaCha20-Poly1305 algorithm. The PPoS enforced on Algorand blockchain, provides an efficient, green consensus for the authorized healthcare nodes. It is compliant with HIPAA and GDPR, has excellent audit features and provides a highly available, emergency override access.
The problem addressed in this study is the lack of a proper conceptualization of the Distributed Ledger Technology-based Central Bank Digital Currency technical language that guides central banks and their stakeholders in the platforms design and implementation.This research aims to improve the DLT-based CBDC knowledge, proposing a human-centered reference model.We use Design Science Research methodology combined with other research methods.The literature has not provided a reference model that can be used to improve the design of the CBDC system to meet regulatory requirements.This study fills the gap in the literature by presenting a human-centered reference model for DLT-based CBDC that serves as a decision-aid tool to study citizens' needs and behaviors, to design user experience, to improve alignment between cultural values and policy roles, and to facilitate communication between experts and stakeholders on currency digitalization process.
Chung, Siu Kei, Francisco Carpio, Andrei Navoichyk, Siarhei Valasovich · 11 authors
The internet faces a sovereignty crisis due to power concentration and data growth among a few hyperscalers, leading to centralization and loss of user control. This consolidation risks censorship and creates single points of failure. While Web3 offers decentralized solutions, they often sacrifice either scalability, decentralization, or security, which are key elements in the blockchain trilemma. These solutions also struggle with limited access to enterprise-grade hardware and frequently rely on centralized infrastructure. The Impossible Cloud Network (ICN) addresses these issues by creating a multi-tiered, decentralized infrastructure layer. ICN offers a composable service layer, an enterprise-grade hardware resource layer, and a transparent, permissionless HyperNode network for performance enforcement. By strategically decoupling and decentralizing each layer, ICN aims to provide an open, extensively scalable infrastructure that ensures digital sovereignty, eliminates single points of trust, enables service programmability, and offers a decoupled architecture for limitless possibilities in the future internet.
Shahad Altamimi, Qasem Abu Al‐Haija, Abdullah AlShuaibi
Incorporating BC technology in Internet of Things (IoT) networks allows secure peer-to-peer communication in Distributed Information Systems (DIS). This research analyzes the protocols implemented on the Blockchain (BC) about data integrity, authentication, and trust issues, which are core challenges of IoT. Thus, the study discussed a secure communication protocol based on BC. These protocols incorporate consensus and smart contracts, which remove central points of failure and improve transparency. Thus, the study setup simulates various IoT devices sending classified messages through a FastAPI backend integrated with Ethereum (Geth) via web3.py. The recent designs and blueprints show where they shine and where overhead or speed still bite. We aim to steer future work toward light, expandable, and privacy-first tools that lock down open IoT systems.
We introduce zkMaP (Zero-Knowledge Succinct Non-Interactive Matrix Multiplication Proofs), a novel non-interactive zero-knowledge proof system for verifying matrix multiplication with significant improvements in efficiency and scalability. Our protocol leverages KZG polynomial commitments and an innovative inner-product reduction technique to reduce the verification of n x n matrix multiplication to a single pairing equation, thereby enabling constant-time verification independent of the matrix size. In particular, zkMaP requires only two pairing operations and produces proofs as small as 320 bytes, yielding a 96 percent reduction in proof size compared to prior schemes. Furthermore, the prover's computational complexity follows the state-of-the-art at O(n^2), with experimental results demonstrating that proofs for 1024 x 1024 matrices can be generated in approximately 12.21 seconds, offering a 16.14x speedup over previous methods. Our implementation also exhibits better memory efficiency, using only 24.58 MB of prover-side RAM for 1024 x 1024 matrices, and supports scalable batch processing, achieving per-proof generation times of 46.79 milliseconds for 1024 instances while maintaining a constant verification time of 3.6 ms.
With the rapid expansion of the digital economy ecosystem, blockchain has become the core technology and theoretical path to support data interaction and trusted transactions. However, it still faces significant challenges in terms of privacy protection, transaction traceability and anti-attack capabilities. To address the above challenges, this study proposes a dynamic trust-aware blockchain security algorithm (DTBCSA) based on differential privacy and zero-knowledge proof. This algorithm is used to improve the system robustness and privacy protection capabilities in multiple scenarios. The core design of the algorithm includes: (1) introducing a dynamic trust evaluation mechanism. This mechanism dynamically adjusts the trust level of the node by analyzing its behavioral characteristics and historical interactions. At the same time, the secondary authentication mechanism is activated when the risk threshold is triggered; (2) embedding a differential privacy mechanism in the computing power transaction and model training process. This mechanism protects sensitive data and model parameters through Laplace noise; (3) using zero-knowledge proof to ensure the non-repudiation of transactions. At the same time, the aggregation and parallel optimization strategies are adopted to significantly reduce the computational overhead of proof and verification. In the experimental part, DTBCSA reduced the acceptance rate of malicious transactions from 70% of the baseline to 8% in the computing power trading market simulation. At the same time, it reduced the reputation distribution imbalance (Gini) from 0.42 to 0.20. In the federated learning collaborative training experiment, DTBCSA reduced the success rate of member inference attacks from 81% to 38% under the condition of privacy budget ε=1. While maintaining privacy protection, it improved the model accuracy by about 1.8 percentage points compared to FedDP. In addition, in the zero-knowledge proof verification performance test, DTBCSA reduced the proof size and generation time through aggregation optimization.
Introduction This study explores the feasibility of embedding futarchy, specifically policy-binding conditional prediction markets anchored to democratically chosen key performance indicators (KPIs) in Decentralized Science (DeSci) governance. By externalizing belief formation to speculative markets while anchoring values democratically, futarchy offers a structurally distinct alternative to existing Decentralized Autonomous Organization (DAO) governance models. Methods Through an empirical analysis of governance data from 13 DeSci DAOs, this study examines governance, participation, and cadence patterns that condition futarchic adoption. A retrospective simulation using proposals from VitaDAO assessed the degree to which historical decisions align with futarchy-preferred outcomes. Results The results indicate full directional alignment under deterministic modeling, suggesting latent compatibility between futarchy and existing DeSci governance. Discussion The analysis further outlines the design principles for implementation, emphasizing measurable KPIs and epistemic diversity. Futarchy, if carefully instantiated, may serve as a governance alternative for funding truth-tracking science through probabilistic decision making and market-based information aggregation.
Ivan Homoliak, Martin Perešíni, Marek Tamaškovič, Timotej Ponek · 6 authors
Proof-of-Stake (PoS) consensus protocols often face a trade-off between performance and security. Protocols that preelect leaders for subsequent rounds are vulnerable to Denial-of-Service (DoS) attacks, which can disrupt the network and compromise liveness. In this work, we present PoS-CoPOR, a single-chain PoS consensus protocol that mitigates this vulnerability by integrating a native onion routing mechanism into the consensus protocol itself. PoS-CoPOR combines stake-weighted probabilistic leader election with an anonymization layer that conceals the network identity of the next block proposer. This approach prevents targeted DoS attacks on leaders before they produce a block, thus enhancing network resilience. We implemented and evaluated PoS-CoPOR, demonstrating its ability to achieve a throughput of up to $110 \mathrm{tx} / \mathrm{s}$ with 6 nodes, even with the overhead of the anonymization layer. The results show that native anonymization can provide robust DoS resistance with only a modest impact on performance, offering a solution to build secure and scalable PoS blockchains.
Artificial Intelligence Generated Content (AIGC) services have shown tremendous potential in digital content creation. However, AIGC service, trading, and product ownership have not been adequately protected due to the lack of a reliable third-party verification platform. Although blockchain-based AIGC management solutions have been proposed, they still suffer from several overlooked issues, such as performance bottlenecks in blockchain systems and repeated sales of AIGC products. Motivated by these limitations, we propose a trusted, efficient, and reasonable AIGC service and trading framework called BC-AIGC by combining identifiers, state channels, and game theory with Web3. Specifically, we first propose an AIGC management scheme based on identifiers and blockchain that enables AIGC ownership to be traced. Then, an AIGC service and trading method based on state channels is proposed, allowing most processes to be completed off-chain and resolving non-cooperation through dispute handling mechanisms, thereby improving efficiency while ensuring security. Furthermore, to find the optimal strategy, we model the interactions among AIGC service participants as a Stackelberg game and prove the existence of a unique Stackelberg equilibrium. Finally, the system prototype and numerical simulations demonstrate the superiority of the proposed BC-AIGC.
Web3 incorporates blockchain technology, decentralisation, and token economies, requiring new service design approaches. Existing design principles, tools, methods, and processes were developed before Web3 and may not address its unique characteristics. This paper extracts four Web3 characteristics − Ownership, Transparency, Tokenisation, and Community Governance − through literature review and constructs three corresponding service design tools: a service concept sheet, community member journey map, and service ecosystem map. Semi-structured interviews with five Web3 and service design experts evaluated these tools through content analysis, identifying improvement areas and refinement proposals.
Carlos Melo, Johnnatan Messias, José Miqueias, Glauber Gonçalves · 6 authors
Sidechains offer partial solutions to Ethereum’s scalability challenges; however, they introduce trade-offs related to security and implementation complexity. These limitations have been further addressed by Layer-2 solutions known as rollups, which combine off-chain computation with on-chain verification, preserving both security and decentralization on the Ethereum platform. This paper proposes a Stochastic Petri Net model to evaluate the feasibility of ZK-Rollups by analyzing their impact on throughput and latency. The results indicate that increased adoption of Layer-2 transactions can enhance system throughput by up to 20%. Conversely, latency may rise by more than 100% when larger batches are used, revealing a fundamental performance trade-off.
Smart contracts control critical financial assets on blockchains, with potential weaknesses risking substantial losses. Thus, smart contract vulnerability detection is essential for maintaining blockchain ecosystem stability. Traditional methods depend extensively on expert-driven patterns, resulting in poor scalability. Although deep learning-based approaches have made significant progress, they still suffer from issues such as inflexible representations, insufficient feature modalities, and limited model capabilities. In this paper, we propose FSGDec, a novel smart contract vulnerability detection framework that fuses sequential information and structural features at the bytecode level. Firstly, an efficient node embedding method is developed for contract control flow graphs, flexibly processing node sequences and incorporating node-specific semantic information associated with weaknesses. Then, by modeling node features as time series signals, an adaptive graph wave network is introduced to automatically capture vulnerability-related structural features. Finally, a classifier is deployed to perform bug detection utilizing the extracted graph-level features that integrate semantic information. Evaluated on two real-world smart contract datasets, the experimental results demonstrate that FSGDec achieves superior performance compared to state-of-the-art baselines.
Javier Godoy, Margarita Capretto, Martín Ceresa, Juan Pablo Galeotti · 7 authors
Smart contracts manage valuable assets, and their immutability hinders bug fixing. Therefore, pre-deployment verification and validation are critical. In fact, auditing has become mandatory in the pipeline of smart contract development. Auditors usually combine manual inspection with automated tools in their auditing work, looking for issues that may be domain dependent (i.e., pertaining to the correct implementation of requirements-which are often informal, partial, and implicit) or independent (e.g., reentrancy, overflow, etc.), To identify domain dependent issues, it is important to understand the non-trivial behavior of the implementation over sequences of calls made by callees playing different roles in the contract. In this paper, we propose a novel approach that combines predicate abstraction with modal transition systems to build abstractions that can help auditors in the smart contract validation process. The required inputs are a set of predicates provided as code and, optionally, constraints over smart contract function parameters. The output is a modal transition system that captures the contract's behavior. We report on a prototype that builds modal abstractions and an evaluation on two established benchmarks where we identified four previously unreported issues.
Blockchain has become a critical enabler of secure data sharing in domains such as healthcare, finance, and digital identity. However, its reliance on classical cryptographic schemes (e.g., RSA, ECDSA, SHA-256) makes current systems vulnerable to emerging quantum computing attacks, raising risks to data confidentiality, integrity, and long-term trust. This paper addresses this challenge by proposing a modular hybrid framework that integrates post-quantum cryptographic (PQC) techniques into blockchain-based personal data sharing. The framework combines lattice-based encryption for protecting off-chain data, hash-based signatures for smart contract authentication, and quantum-safe zero-knowledge proofs and trusted execution environments (TEEs) for privacy-preserving verification and secure key management. To ground this design, we conducted a systematic literature review of 35 studies published between 2018 and 2025, analyzing security, scalability, interoperability, regulatory alignment, and user autonomy. Findings reveal that only 5 out of 35 studies (14%) explicitly addressed quantum threats, with over 80% focusing on theoretical resilience without testing implementation constraints. Furthermore, 90% of proposals neglected smart contract compatibility, and only 8% (3/35) incorporated TEEs, underscoring implementation barriers in contract execution, secure key management, and performance integration. Prototype evaluation demonstrated that the framework sustained 1,500 TPS on Hyperledger Fabric, achieved a 75% reduction in storage bloat using IPFS, and supported GDPR-aligned workflows with 99.98% audit log completion and 95% successful erasure requests. Privacy was further strengthened through zk-STARK proofs, which reduced unauthorized access by 40%, while TEEs improved key management efficiency by ~28%. Although PQC introduced 5–12 seconds of latency, consent revocation was processed in under 2.1 seconds, highlighting both the feasibility and trade-offs of practical post-quantum deployment. This work demonstrates a clear pathway toward quantum-resilient blockchain infrastructures that safeguard personal data, comply with regulatory standards, and maintain user trust in the quantum era.