Bitcoin custody systems are constructed under conditions of full knowledge and activated under conditions of partial knowledge. The person who designs a custody arrangement understands its components, dependencies, and intended operation. The person who later encounters that systemâoften an executor, trustee, or heirâmust interpret and operate it without access to the designer's contextual understanding. This paper defines a descriptive framework for examining Bitcoin custody systems under stress conditions at a point in time, producing reference records for later interpretation. The framework treats examination as observation rather than evaluation: it records what exists, what dependencies connect components, and how the system behaves under modeled stress scenarios. It explicitly excludes advice, recommendations, certification, and adequacy assessment. The framework introduces four modeled outcome statesâsurvives, constrained, blocked, and indeterminateâthat describe observed system behavior without normative judgment. It defines stress conditions including owner absence, cognitive unreliability, device loss, institutional delay, and coordination failure. It specifies what reference artifacts examination produces: system snapshots, scenario-bound observations, dependency maps, and assumption registries. The paper addresses how professionalsâattorneys, fiduciaries, advisorsâcan engage with examination records without overstepping interpretive boundaries. It distinguishes what records can establish (what was described, what was modeled, what assumptions applied) from what records cannot establish (adequacy, correctness, future outcomes). The framework is offered as a reference for professional contexts where Bitcoin custody must be understood by parties other than its original designer.
The increasing use of the internet by children in Azerbaijan to access harmful content demonstrates the weakness and absence of age verification mechanisms. The Law on the Protection of Children from Harmful Information has a comprehensive system of labeling information that is harmful to children on the offline and broadcasted information and has no direct enforcement mechanisms on the labeling of information on online and digital platforms. This research evaluates both the advantages and the missing aspects of the Azerbaijani system, outlines the enforcement mechanisms of the Texas House Bill 1181, and analyzes the constitutional and practical aspects of the enforcement mechanism of mandatory age verification. The Texas model provides a legal framework for age verification and was upheld under intermediate scrutiny in Free Speech Coalition, Inc. v. Paxton, raising significant privacy concerns. One of the concerns was disclosing users personal information to private platforms, which creates risks related to data collection, storage and potential misuse. Azerbaijan's digital identification systems, ASAN Imza and SIMA Imza, are implemented and are privacy- preserving, and therefore, the Texas system can be avoided by use of the given digital identification systems with the inclusion of the zero-knowledge proofs. The study focuses on the policy and the legal framework on the system to enhance the privacy aspects of the rights of the children, and in accordance with the data protection system, describes in detail the steps, legal aspects, and proposed changes to the privacy systems.
Compliance verification in regulated markets requires that verifiers obtain confidence in an entity's regulatory status before making downstream decisions. The conventional resolution of this requirement is full disclosure of underlying evidence to each verifier on each verification occasion, with substantial cost to the entity's informational privacy and substantial duplication of sensitive-data storage across verifier organisations. Modern cryptography offers, in principle, the tools to better balance verifier information needs against entity privacy: zero-knowledge proof systems, selective-disclosure credentials, vector commitments, and privacy-preserving aggregation primitives are now mature enough for serious regulatory consideration. Yet the legal and regulatory frameworks under which these tools would be deployed have not caught up with their technical readiness. We develop the legal and policy case for adoption of a cryptographic framework for selective disclosure in regulated markets. We analyse the framework's interaction with data-protection law (UK GDPR, EU GDPR, US state-level privacy regimes), financial-services regulation (FATF Recommendations, FCA rules, BSA/AML obligations), employment law (right-to-work, employment background screening), and identity system regulation (eIDAS 2.0, US REAL ID, digital identity wallets). We identify the principal legal uncertainties that constrain adoption and propose specific reforms to resolve them: data-protection safe harbours for cryptographic verification protocols; reconceiving regulatory data-retention requirements in terms of cryptographic attestations rather than underlying evidence; standardising regulator-grade revocation mechanisms; clarifying the legal status of zero-knowledge proofs as admissible evidence in supervisory and enforcement actions. We make four policy recommendations: (i) data-protection regulators (ICO, EDPB, equivalent) should issue guidance affirming that cryptographic selective-disclosure protocols meeting specified properties are compliant with data-protection law; (ii) financial-services regulators should issue guidance clarifying that cryptographic attestations satisfying specified properties can substitute for evidence retention obligations under AML/KYC rules; (iii) standard-setters should coordinate cross-jurisdictional protocol standards through W3C, IETF, and ISO/TC 307 with regulator participation; (iv) legislators in jurisdictions with active digital-identity programmes (UK, EU, US, Singapore) should ensure that statutory frameworks accommodate selective-disclosure verification. The paper contributes to the law-and-economics literature on data sharing under privacy constraints, to the policy economics of RegTech, and to the legal-academic literature on emerging-technology regulation. It complements the technical and economic threads of work developed in companion papers in this series.
Digital identity verification often forces a privacy trade-off, where users must disclose sensitive personal data to prove simple eligibility criteria. As blockchain applications integrate with regulated environments, this over-disclosure creates significant risks of data breaches and surveillance. This work proposes a general Selective Disclosure Framework built on Ethereum, designed to decouple attribute verification from identity revelation. By utilizing client-side zk-SNARKs, the framework enables users to prove specific eligibility predicates without revealing underlying identity documents. We present a case study, ZK-Compliance, which implements a functional Grant, Verify, Revoke lifecycle for age verification. Preliminary results indicate that strict compliance requirements can be satisfied with negligible client-side latency (< 200 ms) while preserving the pseudonymous nature of public blockchains.
Alen Horvat, Steffen Schwalm, Johannes Sedlmeir, Hakan Yildiz
Among the privacy-enhancing technologies explored in the context of the European Digital Identity (EUDI) Wallets, zero-knowledge proofs stand out for their ability to maintain established levels of cryptographic verifiability while enabling data minimisation â relative to the requirements expressed by the relying party (RP). However, legal frameworks in many sectors require the collection of verifiable data beyond the RPâs immediate needs, which may substantially narrow down the scope of data minimisation that can be achieved in regulated domains. Accordingly, this paper examines the tensions between the strict data minimisation requirements for the EUDI Wallets and the extensive legal proof obligations that relying parties must fulfil. Our analysis of the regulatory foundations and relevant technical mechanisms identifies documentation, audit, and long-term preservation obligations as key sources for friction. We explore the implications of the corresponding tensions, point to gaps in current standardisation and compliance regimes, and suggest potential technical and non-technical solution approaches that could help reap the benefits advanced privacy-enhancing technologies can offer in practice.
Abstract Cheap, disposable online identities make abuse easier to externalize. Users can harass, evade bans, amplify content through fake accounts, or abandon a damaged reputation at low cost, while other users, moderators, and platforms bear the consequences. This paper examines verified pseudonymity as an institutional response to that problem. First, I model online communities as club-governed informational commons in which incivility degrades the shared environment and raises enforcement costs. The model shows that conduct can improve when sanctions attach to a persistent pseudonymous identity and when users have future access, reputation, or governance rights at stake. Second, I compare verified pseudonymity with open pseudonymity, real-name mandates, centralized know-your-customer verification, algorithmic moderation, and no intervention. Decentralized identifiers, verifiable credentials, proof of personhood, and non-transferable standing credentials matter because they can separate authentication from public identification. Third, I add a community-currency layer that separates access to scarce attention from governance rights. The result is a governance framework in which accountability depends less on public naming than on durable standing, credible sanctions, and reusable privacy-preserving credentials.
The Internet has evolved from its early promise of global connection and freedom into a centralized system dominated by Big Tech and governments, resulting in widespread data exploitation, surveillance, censorship, and erosion of user privacy and ownership. This paper traces the historical development of Web2 infrastructure, its foundational flawsâparticularly the linkage of digital identities to real-world persons and the unchecked power of intermediariesâand the societal pressures that have exposed these vulnerabilities through events such as the Great Firewall of China, the Snowden revelations, the Cambridge Analytica scandal, and large-scale hacks. In response, the paper positions Web3 , underpinned by blockchain technology, as a necessary paradigm shift toward a decentralized, user-centric Internet. Web3 severs the tie between digital and physical identities, enables true data ownership, peer-to-peer encryption, global accessibility without geo-restrictions, and algorithmic governance that reduces reliance on potentially abusive middlemen. It argues that Web3 can encode core democratic values, including freedom of expression as articulated in Article 19 of the Universal Declaration of Human Rights, while addressing resistance from governments (concerned with control and taxation), Big Tech (threatened by loss of data monopolies), and everyday users (wary of complexity and perceived risks). The paper examines ethical considerations, potential misuse by bad actors, and the dual nature of technological innovation. It proposes four critical criteria for evaluating successful Web3 implementations: 1) affordability and equitable access with long-term cost reduction; 2) robust protection of individuals through privacy and bias mitigation, coupled with "freedom of speech, not reach"; 3) absence of any central governing body with control over development; and 4) a community-representative judicial system for handling violations of shared terms of service. Ultimately, this work contends that Web3 represents an inevitable evolution capable of empowering billions of usersâparticularly those in repressive regimesâby fostering transparency, equity, and self-governance, provided implementations adhere to these ethical and practical standards. It calls for cautious optimism, due diligence, and open-source verification in the transition to a more liberated and democratic digital era.
This study presents a comprehensive bibliometric analysis of blockchain identity management research published between 2010 and 2025, aiming to map its intellectual structure, thematic evolution, and global collaboration patterns. Using data retrieved from the Scopus database and analyzed with VOSviewer, the study applies network visualization, overlay visualization, density mapping, citation analysis, and co-authorship analysis to uncover dominant research streams and emerging frontiers. The results reveal that the field is conceptually centered on blockchain-based authentication and decentralized identity management systems, with increasing scholarly attention toward privacy-preserving mechanisms such as zero-knowledge proofs, anonymity, and data protection. Thematic evolution indicates a clear transition from foundational infrastructure-oriented studies to application-driven and regulatory-sensitive research domains, including e-government, IoT, healthcare, and digital governance. Collaboration analysis highlights the leading role of China and India, supported by strong transcontinental linkages with the United States and European countries, reflecting a globally interconnected yet regionally concentrated research landscape. By systematically mapping publication trends, thematic clusters, and collaboration networks, this study provides a structured knowledge base that supports future theoretical development, guides practical implementation, and informs policy formulation in blockchain-based digital identity ecosystems.
National identity systems require efficient, equitable decision-making that safeguards personal data. This article proposes a Self-Sovereign Identity (SSI) architecture, supported by a Verify-Without-Reveal (VWR) framework, designed for national-scale implementation. SSI places credentials in a citizen wallet and enables selective disclosure and zero-knowledge proofs, so services can verify attributes without seeing underlying records. VWR adds the policy and accountability spine: yes/no attribute APIs for holder-absent cases, purpose-bound and zero-trust enforcement on every call, and an immutable audit layer on a permissioned ledger. The study synthesises current standards and leading implementations in Europe and worldwide and formulates a deployable blueprint with clear roles, consent and lawful-override flows, per-agency pseudonyms, and regulator and citizen visibility. The study outlines reference APIs, user experiences for wallets and verifiers, and performance metrics suited for national workloads. Privacy-preserving AI strengthens biometric liveness, fraud detection, and anomaly response without centralising sensitive data. The framework aligns with GDPR data minimisation and purpose limitation, supports the European Digital Identity Wallet, and meets high-risk AI governance requirements. Results show how SSI proofs and VWR controls reduce unconsented disclosure and cross-agency browsing, while keeping latency low and interoperability high. The contribution is both conceptual and operational: a phased migration path that turns verify-without-reveal into the default mode for government and regulated services, improving security, inclusion, and public trust.
A system design built on blockchain technology presents a fundamental challenge: the inherent transparency of the blockchain conflicts with the growing need for user privacy. This dissertation explores how Zero-Knowledge Proofs (ZKPs) can be strategically combined with blockchain to strike a balance between these competing demands. The dissertation analyzes the challenges of privacy and transparency and provides an overview of solutions across the privacy-transparency solution space, drawing from the authorâs original research and the broader academic landscape. On the privacy-centric side, it proposes a privacy-preserving design that utilizes off-chain ZKPs. In contrast, on the transparency-centric side, it presents a transparency-enhancing design that leverages on-chain data to build trust. In the middle, it discusses a taxonomy of hybrid applications whose unique combination of on-chain privacy (via ZKPs) and blockchain transparency reveals both a disruptive potential and significant regulatory challenges.
Stepan Bakhaev, Josďż˝ Carlos Camposano, Annika Wolff, Kari Smolander
This paper analyzes stakeholdersâ understanding of an electronic identification (e-ID) system based on artificial intelligence and distributed ledger technology. We address the question "How is the trustworthiness of a novel information system for e-ID influenced by the stakeholdersâ understanding of its base technologies?". Our findings are based on a qualitative analysis of a questionnaire and interviews with stakeholders from a system development project focused on e-ID for online public services. We found that current e-ID systems have good usability but lack dialog and feedback mechanisms, whereas technical robustness and data protection are deemed essential attributes of emerging solutions. We identified four profiles of prospective users according to variations of trust in the new e-ID system. These findings suggest the need for greater transparency to facilitate the adoption of nascent digital identity solutions.
Thanassis Tiropanis, George Roussos, Mohammad Bahrani, Mohamed Ragab
The growing demand for data ownership and privacy is reshaping how information is accessed, managed, integrated, and recommended. Building on the inaugural DESERE workshop at The Web Conference 2024, this second edition advances research on Decentralised Search and Recommendation platforms such as Personal Online Datastores (PODs), where users retain control of their data and explicitly manage permissions. As ecosystems decentralise, traditional information retrieval must be revisited while standards for new techniques and system designs are developed to ensure efficient, accurate, and privacy-preserving search. The Second DESERE workshop at CIKM 2025 focuses on infrastructures and retrieval algorithms for user-controlled data. It convenes a cross-disciplinary community spanning data retrieval, management and integration, semantic technologies, recommendation systems, privacy-aware computing, and search efficiency to explore approaches that prioritize user agency, data ownership, and scalable retrieval across PODs and related architectures. Through paper presentations, panels, and interactive sessions, the workshop will highlight challenges, opportunities, and solutions for privacy-preserving IR. These discussions are especially relevant to domains where user-centric design and data stewardship are critical-such as personal finance, education, and high-stakes areas like criminal justice and health.
A TANULMĂNY CĂLJAA tanulmĂĄny cĂŠlja a Bitcoin buborĂŠkok kialakulĂĄsĂĄnak vizsgĂĄlata, megĂŠrtĂŠse. A buborĂŠkok erĹs hasonlĂłsĂĄgot mutatnak a Gartner-fĂŠle hype-gĂśrbe alakjĂĄval, ezĂŠrt az egyes buborĂŠkok ĂŠs a hype-gĂśrbe kapcsolata is ismertetĂŠsre kerĂźl. Ezek mellett a Bitcoin-buborĂŠkok kialakulĂĄsĂĄt elĹsegĂtĹ tĂŠnyezĹk feltĂĄrĂĄsĂĄra tĂśrekedtĂźnk. ALKALMAZOTT MĂDSZERTAN A Bitcoin ĂĄrfolyamĂĄnak historikus adatait elemeztĂźk, melyek alapjĂĄn a buborĂŠkok kirajzolĂłdnak. A buborĂŠkok lĂŠtezĂŠsĂŠnek alĂĄtĂĄmasztĂĄsĂĄra, illetve a Gartner-fĂŠle hype-gĂśrbĂŠvel valĂł azonosĂtĂĄs ĂŠrdekĂŠben kiszĂĄmoltuk az egyes buborĂŠkok kĂźlĂśnbĂśzĹ idĹszakaihoz tartozĂł kockĂĄzatokat, hozamokat is. IllesztettĂźk a hype-gĂśrbĂŠt a Bitcoin ĂĄrfolyamĂĄnak alakulĂĄsĂĄra, illetve a korrelĂĄciĂłs kapcsolatot is vizsgĂĄltuk. LEGFONTOSABB EREDMĂNYEK A szĂłrĂĄsbĂłl szĂĄmĂtott kockĂĄzatok, illetve a relatĂv szĂłrĂĄsok is alĂĄtĂĄmasztottĂĄk a feltĂŠtelezĂŠst, mely szerint az egyes Bitcoin-buborĂŠkok kĂśvetik a Gartner-fĂŠle hype-gĂśrbe alakjĂĄt. A gĂśrbĂŠk illesztĂŠse ĂŠs a korrelĂĄciĂł vizsgĂĄlata pedig kimutatta, hogy van kapcsolat a hype ĂŠs az ĂĄrfolyam alakulĂĄsa kĂśzĂśtt. A szabĂĄlyozĂĄs szerepe kritikus lehet a kriptovalutĂĄk ĂĄrfolyamĂĄnak alakulĂĄsĂĄban, ĂŠs a kĂźlĂśnbĂśzĹ orszĂĄgokban bevezetett szabĂĄlyozĂł intĂŠzkedĂŠsek jelentĹs hatĂĄst gyakorolhatnak a befektetĹi bizalomra ĂŠs az ĂĄrfolyamokra. A Bitcoin-bĂĄnyĂĄszat felezĂŠse szintĂŠn fontos esemĂŠny, amely befolyĂĄsolhatja a kĂnĂĄlatot ĂŠs keresletet ĂŠs ennek megfelelĹen az ĂĄrfolyamokat is. Az utĂĄnzĂł magatartĂĄs, vagyis a befektetĹk tendenciĂĄja arra, hogy mĂĄsok viselkedĂŠsĂŠt mĂĄsoljĂĄk, szintĂŠn jelentĹs tĂŠnyezĹ a buborĂŠkok kialakulĂĄsĂĄban. VĂŠgĂźl az intĂŠzmĂŠnyi szereplĹk stabilizĂĄlĂł hatĂĄsĂĄt ismertettĂźk. GYAKORLATI JAVASLATOK A tanulmĂĄnybĂłl kiderĂźl, hogy a fent emlĂtett tĂŠnyezĹk igen nagy befolyĂĄst gyakorolnak a Bitcoin ĂĄrfolyamĂĄnak alakulĂĄsĂĄra, melyek kĂśzĂźl a bĂĄnyĂĄszatĂŠrt jĂĄrĂł jutalmak felezĂŠse a leginkĂĄbb szembetĹąnĹ, illetve szĂĄmĂtĂĄssal alĂĄtĂĄmaszthatĂł. Az Ăşj szabĂĄlyozĂĄsok megjelenĂŠsĂŠvel nem tudunk szĂĄmolni, viszont a felezĂŠssel jĂĄrĂł ĂĄrfolyamvĂĄltozĂĄssal igen, melynek fĹ indikĂĄtora az utĂĄnzĂł magatartĂĄs, hiszen a befektetĹk hozamaik maximalizĂĄlĂĄsĂĄra tĂśrekednek. Ezek alapjĂĄn a tanulmĂĄny rĂĄvilĂĄgĂt, hogy egy igen kockĂĄzatos befektetĂŠsi formĂĄrĂłl van szĂł, melynek elĹrejelzĂŠse igen nehĂŠz feladat.
Blockchain technology has revolutionized digital transactions by offering decentralization, transparency, and immutability. However, its inherent transparency often conflicts with the need for user privacy and anonymity, raising significant concerns regarding accountability, especially in regulatory and legal contexts. This study explores the delicate balance between anonymity and accountability in blockchain systems, proposing a framework that ensures both privacy and compliance with regulatory requirements. The research addresses key challenges in balancing these two aspects, evaluates the effectiveness of existing privacy-preserving technologies such as zero-knowledge proofs and ring signatures, and introduces the Privacy-Accountability Balanced Blockchain (PABB) Framework. This framework integrates Selective De-Anonymization, Self-Sovereign Identity (SSI), and the Adaptive Privacy-Accountability Control (APAC) Algorithm to dynamically adjust privacy levels based on regulatory conditions. Through theoretical analysis, mathematical modeling, and empirical validation, preserving privacy for 92% of transactions while enabling selective de-anonymization in high-risk cases, the study demonstrates that the APAC Algorithm effectively balances privacy and compliance needs. The findings suggest that privacy-conscious blockchain systems can coexist with accountability mechanisms, paving the way for ethical and legally sound blockchain applications. The study concludes that the PABB Framework offers a practical and scalable approach to achieving this balance, fostering trust among users and regulators alike.
IvĂĄn AbellĂĄn Ălvarez, Pol HĂślzmer, Johannes Sedlmeir
Digital identity wallets promise significant advancements in digital identity management by offering users a high degree of convenience, security, and control over their data disclosure. However, there is also criticism regarding their privacy guarantees, especially when used in regulated use cases that require high levels of assurance on the correctness and binding of a legal identity. In this paper, we present a comprehensive privacy model and analysis of one of the most prominent digital wallets â the European Digital Identity Wallet (EUDIW) â as specified by the Architecture and Reference Framework (ARF) and the eIDAS 2.0 regulation. We employ a suite of qualitative privacy risk assessment methods to systematically map and evaluate information flows in three key use cases. Our analysis identifies multiple privacy risks â including linkability, identifiability, and excessive attribute data disclosure â and reveals that although the ARF is designed to comply with privacy-by-design principles, inherent design choices, such as the reliance on SD-JWT and mDOC data formats, as well as the concept of a Wallet Unit Attestation (WUA), retain risks to user privacy. Building on our findings, we then highlight how advanced Privacy-Enhancing Technologies (PETs), such as (general-purpose) Zero-Knowledge Proofs (ZKPs), can reduce or mitigate some of these risks.
Cross chain interoperability in blockchain systems exposes a fundamental tension between user privacy and regulatory accountability. Existing solutions enforce an all or nothing choice between full anonymity and mandatory identity disclosure, which limits adoption in regulated financial settings. We present VeilAudit, a cross chain auditing framework that introduces Auditor Only Linkability, which allows auditors to link transaction behaviors that originate from the same anonymous entity without learning its identity. VeilAudit achieves this with a user generated Linkable Audit Tag that embeds a zero knowledge proof to attest to its validity without exposing the user master wallet address, and with a special ciphertext that only designated auditors can test for linkage. To balance privacy and compliance, VeilAudit also supports threshold gated identity revelation under due process. VeilAudit further provides a mechanism for building reputation in pseudonymous environments, which enables applications such as cross chain credit scoring based on verifiable behavioral history. We formalize the security guarantees and develop a prototype that spans multiple EVM chains. Our evaluation shows that the framework is practical for today multichain environments.
The rise of centralised social networks has consolidated power among a few major technology companies, raising critical concerns about privacy, censorship, and transparency. In response, decentralised alternatives, including Web3 platforms like Decentralised Social (DeSo) and Fediverse platforms such as Mastodon, have gained increasing attention. While prior research has explored individual aspects of decentralised networks, comparisons between Fediverse and Web3 platforms remain limited, and the unique dynamics of Web3 networks like DeSo are not well understood. This study provides the first in-depth study of DeSo, characterising user behaviour, discourse, and economic activities, and compares these with Mastodon and memo.cash . We collected over 3.1M posts from 13K users on DeSo and Mastodon, along with 11M DeSo on-chain transactions via public APIs. Our analysis reveals that while DeSo and Mastodon share similarities in passive content engagement, they differ in their use of URLs, hashtags, and community focus. DeSo is primarily oriented around Decentralised Finance (DeFi) topics, whereas Mastodon hosts diverse discussions with an emphasis on news and politics. Despite DeSoâs decentralised social graph, its transaction graph remains centralised, underscoring the need for further decentralisation in Web3 platforms. Additionally, while wealth inequality exists on DeSo, low transaction fees promote user participation irrespective of financial status. These findings provide new insights into the evolving landscape of decentralised social networks and highlight critical areas for future research and platform development.
The rapid progress of large-scale models, including foundational and generative, brings to the forefront the tension between data-driven innovation and core privacy concerns. Such contracts as the GDPR and the undue privacy threats of data aggregation make centralized training approaches less desirable. To analyze the dataâs distributed characteristics and their application to FLO, we investigate the role of federation analytics in a plausible paradigm that shunts data. In this paper, we present a new federated learning (FL) framework enhanced with cutting-edge privacy technologies (PET) such as Differential privacy for user-level formal guarantees of confidentiality, and strengthened secure Multi-Party Computation (SMPC), which guards the model updates. This paper studies more recent approaches to resolving the principal challenges of FL: statistical heterogeneity, communication bottlenecks, and vulnerability to adversarial attacks. We greatly appreciate what this new method portends, especially for training large language models (LLMs) and the more delicate areas of healthcare and finance. By evaluating certain existing limitations, such as the complexities of federated fine- tuning and model fairness, it is clear that an architecture with exemplary performance in FL serves as a model for scalable, secure, and privacy cop.
This paper proposes a hybrid access control system that integrates the usability of Web2 authentication (Google Login) with the transparency and integrity of Web3 technologies (blockchain and smart contracts). The system enables users to authenticate via their existing Google accounts without managing crypto wallets or private keys, while access permissions are securely recorded on-chain through smart contracts. To ensure cryptographic key security without relying on a centralized authority, the design incorporates Distributed Key Management (DKM). This approach addresses the challenge of balancing usability with verifiability in data access control. By embedding decentralized guarantees within a centralized web service interface, the system enables practical and transparent access control. The proposed architecture demonstrates the potential for a general-purpose, auditable module that facilitates user-consented data sharing with third parties.
Although the P2P power transactions using the multiagent deep deterministic policy gradient (MADDPG) algorithm has been extensively studied, there are still challenges in privacy protection and training incentives. Furthermore, the stability and efficiency of the strategy decreases when dealing with nonindependent identically distribution (Non-IID) data from heterogeneous prosumers. Therefore, this article proposes a blockchain-enabled asynchronous federated learning-MADDPG (BEAFL-MADDPG) framework designed to enhance the training efficiency of heterogeneous prosumers while safeguarding data privacy. The framework includes a novel P2P energy trading model that facilitates energy trading amidst incomplete information while ensuring privacy assurances. In addition, a BEAFL-MADDPG algorithm is proposed, which accelerates training processes and enables parallel computation among agents. This algorithm enhances the efficiency of algorithm and empowers the training of diverse prosumers. Furthermore, a blockchain-enabled training mechanism and prosumer incentive scheme are proposed that not only encourage prosumer engagement in training but also ensure traceable transactions without the need for trust among participants. These mechanisms promote transparency and integrity, fostering a collaborative and secure environment for energy trading. Simulation results demonstrate that the framework achieves peak load reduction through optimized P2P trading, maintains computation efficiency across discount rates, and ensures secure transactions via blockchain-based incentives. These practical benefits support scalable and sustainable community microgrid operations.
Decentralized technologies such as blockchain and federated learning have emerged as promising solutions to improve privacy, transparency, and security in distributed environments. This paper aims to provide updated research directions concerning the unresolved issues of linkability and traceability in decentralized technology transactions. A systematic review was conducted using Scopus and Web of Science databases, covering studies published between 2017 and 2023. A total of 313 papers were initially identified, screened, and filtered based on inclusion and exclusion criteria, resulting in 29 relevant studies. The analysis indicates that most prior works focused on privacy preservation and incentive mechanisms but neglected linkability and traceability concerns. Several approaches, including ring signatures, CryptoNote protocols, and smart contract-based incentives, were identified as potential solutions. While blockchainâfederated learning integration enhances privacy, unresolved traceability and linkability issues still pose significant risks in sensitive domains such as healthcare and finance. Future work should prioritize addressing these issues to ensure secure, anonymous, and scalable decentralized transactions.
Kriti Patidar, Swapnil Jain, Mohammad Husain, Mohd Muqeem ¡ 9 authors
As IoT-connected devices, sometimes referred to as the Internet of Things (IoT), continue to proliferate, existing centralized identity management systems struggle in the large scale due to issues with scalability, privacy and security. For these reasons, centralized identity management systems will not meet the requirements of large-scale IoT deployments. In this paper, we suggest a decentralized identity management system to authenticate and authorize IoT devices based on a hybrid blockchain and Zero-Knowledge Proof (ZKP) protocol. The proposed system utilizes decentralized identifiers (DIDs), verifiable credentials (VCs) and a hierarchical web-of-trust structure as part of the identity management process. The identity and credentials can be created and validated in a decentralized manner and locally, using smart contracts and lightweight consensus models such as Proof of Stake (PoS) and Practical Byzantine Fault Tolerance (PBFT). The performance evaluation demonstrated the performance in respect of authentication latency businesses managed to get the latency to 250 ms, throughput reaching to 200 messages per second and energy efficiency improved to 300mW/device. Based on the baseline comparisons including PoW, OAuth and Hash-MAC based systems included, the proposed method is scalably better, provides greater security against DDoS and MITM attacks and used less memory. The proposed method yields a robust, fully decentralized identification system for managing IoT identities without requiring a centralized authority, allowing scalable and secure interactions across distributed networks.
Abstract In the context of the IoT platform, the smart home represents a quintessential application scenario. Here, device-to-device (D2D) collaboration serves as the core element of its ecosystem, playing a crucial role in implementing diversified automated execution scenarios that are customized to fulfill user requirements. The progressive integration of edge computing and AI technologies has enhanced the collaboration among heterogeneous devices. Nevertheless, the conventional centralized D2D collaboration authorization decision-making supported by a single IoT Hub violates the Principle of Least Privilege (PoLP), which is a foundational design tenet that has been empirically validated as an optimal engineering practice for enhancing system security and reliability in IoT ecosystems. If there is a trade-off of PoLP violations, it fails to meet the usersâ Quality of Experience (QoE). To address this issue, we propose D2DA, a distributed authorization decision-making model for smart home D2D collaboration, which constructs a distributed decision-making consensus network suitable for the edge side of smart homes by leveraging distributed ledger technology. D2DA presents a machine learning algorithm with a time complexity of O ( n ). Through this algorithm, consensus nodes can be efficiently and dynamically selected. Furthermore, D2DA ensures the security of the D2D collaboration process via wallets and hash verification. Extensive experiments conducted on a real-world smart home scenario validate that the decision-making latency of D2DA is on par with that of a single IoT Hub mode. The average latency for verifying the correctness of the newly added execution results is only 0.08% of the system time of D2DA, which is negligible.