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 users’ 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.
Alvaro Gómez Vieites, Christian Delgado-von-Eitzen, Diego Estévez Garcia
For years, combining the immutability associated with blockchain technology with the European Union’s General Data Protection Regulation (GDPR) has been considered a practically unsolvable conflict due to the very nature of blockchain and the GDPR. This article presents the GAVIN project (GDPR-Compliant Blockchain-Based Architecture for Universal Learning, Education and Training Information Management), a pioneering initiative that overcomes this challenge through an innovative technical and legal approach to trusted digital academic certification. Developed by atlanTTic (University of Vigo) and funded by the European Union, GAVIN proposes a scalable architecture that combines off-chain storage, encrypted Hash-Based Message Authentication Code (HMAC) anonymization, access notarization, and blockchain-based access control. The legal validation of the working prototype under development demonstrates that blockchain decentralization is compatible with GDPR compliance. The model is presented as a replicable reference for institutions wishing to leverage distributed ledger technologies without compromising personal data protection. This paper details the legal design, technical architecture, and compliance mechanisms, offering a practical framework for implementing decentralized systems with privacy by design.
Blockchain technology has emerged as a promising solution for improving traceability across global supply chains, offering tamper-proof records and increased transparency.However, concerns related to data privacy, confidentiality, and interoperability continue to hinder widespread adoption.This paper proposes a comprehensive framework addressing these key challenges by combining privacy-preserving techniques-such as permissioned ledgers, zero-knowledge proofs, and verifiable credentials-with industry-driven data standards (GS1 EPCIS, W3C Verifiable Credentials).We first review the landscape of blockchain traceability solutions and outline critical requirements from regulatory and operational perspectives.Next, we detail our proposed privacy-preserving and interoperable architecture, incorporating off-chain storage, role-based permissions, and selective disclosure mechanisms to accommodate the diverse needs of modern supply chains.We illustrate these concepts through a high-level system design, accompanied by implementation considerations.Our evaluation highlights that successful adoption depends on carefully balancing transparency and confidentiality, supplemented by robust governance structures and standard APIs.The paper concludes by discussing future directions for blockchain traceability, emphasizing scalability, user-centric design, and cross-chain interoperability as critical enablers of a global, privacypreserving supply chain ecosystem.
Traditional centralized scholarship evaluation processes typically require students to submit detailed academic records and qualification information, which exposes them to risks of data leakage and misuse, making it difficult to simultaneously ensure privacy protection and transparent auditability. To address these challenges, this paper proposes a scholarship evaluation system based on Decentralized Identity (DID) and Zero-Knowledge Proofs (ZKP). The system aggregates multidimensional ZKPs off-chain, and smart contracts verify compliance with evaluation criteria without revealing raw scores or computational details. Experimental results demonstrate that the proposed solution not only automates the evaluation efficiently but also maximally preserves student privacy and data integrity, offering a practical and trustworthy technical paradigm for higher education scholarship programs.
Federated Learning (FL) enables collaborative model training across maritime devices without the need to share raw data. However, challenges such as data heterogeneity and unreliable marine communications impede its performance and security. In this work, we propose a Blockchain-based Active Client Selection Strategy for FL in Shipping (BAFLS), which utilizes blockchain technology to create a secure and auditable environment for node registration and parameter exchange. A lightweight consensus algorithm is introduced to dynamically elect aggregation nodes based on residual energy, reputation, and computing power, improving fault tolerance and reducing resource consumption. Based on such, a Top-kactive learning strategy is designed to select the most informative clients, balancing data utility and privacy protection. Security evaluation and analysis demonstrate that BAFLS effectively resists aggregation attacks and privacy inference. Experimentations on FMNIST, HAR, and ShipNetwork10 datasets show that BAFLS achieves up to 2.4% higher accuracy, reduces convergence rounds by up to 44%, and consistently lowers communication overhead compared to the baseline under various degrees of label and feature heterogeneity.
This chapter provides a comprehensive overview of the legal and regulatory landscape surrounding Web3. The chapter explores the challenges that decentralized technologies face, including the application of traditional laws to crypto projects, intellectual property issues, and data protection in a transparent blockchain environment. It discusses various frameworks – from securities laws and e-money regulations to anti-money laundering (AML)/counter-terrorist financing (CTF) requirements and VASP guidelines – highlighting the need for robust compliance strategies as jurisdictions worldwide tighten oversight. Real-world examples, such as the U.S. Securities and Exchange Commission’s (SEC) actions and international regulations like Markets in Crypto-Assets (MiCA), illustrate how these rules impact project structure and operations. The chapter also emphasizes the role of smart contracts in automating compliance and the importance of risk management in a rapidly evolving digital economy. Ultimately, it underscores that proactive legal adherence and transparent governance are essential for building trust and ensuring the sustainable growth of Web3 initiatives.
The traditional voting process, whether paper-based or electronic, is often criticized for its lack of transparency, susceptibility to fraud, and dependence on centralized authorities. Blockchain technology, particularly in the Web3 ecosystem, provides a decentralized, secure, and tamper-proof solution for digital voting. This paper explores how blockchain can enhance election integrity by leveraging decentralized applications (DApps), smart contracts, and cryptographic security. The proposed system employs Ethereum-based smart contracts to automate vote casting and tallying while ensuring voter privacy through zero-knowledge proofs. Decentralized Identity (DID) is integrated for secure authentication, preventing double voting and identity fraud. The paper discusses system architecture, security considerations, scalability challenges, and real-world applications of blockchain voting, highlighting how Web3 can transform democratic elections.
The digitization of democratic processes promises greater accessibility but presents challenges in terms of security, privacy, and verifiability. Existing electronic voting systems often rely on centralized architectures, creating single points of failure and forcing too much trust in authorities, which contradicts democratic principles. This research addresses the challenge of creating a secure, private e-voting system with minimized trust dependencies designed for the most versatile personal device: the smartphone. We introduce SmartphoneDemocracy, a novel e-voting protocol that combines three key technologies: the emerging European Digital Identity (EUDI) Wallet for Sybil-resistant identity verification, Zero-Knowledge Proofs for privacy-preserving validation, and a peer-to-peer blockchain (TrustChain) for a resilient, serverless public bulletin board. Our protocol enables voters to register and cast ballots anonymously and verifiably directly from their smartphones. We provide a detailed protocol design, a security analysis against a defined threat model, and a performance evaluation demonstrating that the computational and network overhead is feasible for medium- to large-scale elections. By developing and prototyping this system, we demonstrate a viable path to empower citizens with a trustworthy, accessible, and user-controlled digital voting experience.
Jul 11, 2025·The international archives of the photogrammetry, remote sensing and spatial information sciences/International archives of the photogrammetry, remote sensing and spatial information sciences
Abstract. Environmental surveillance, emergency response, and smart city planning all require the use of geospatial data, which includes satellite imagery, cartographic records, and real-time GPS coordinates. The high sensitivity and value of location-specific information make it unsafe to store and transmit it through conventional, centralized means, which can result in privacy breaches, unauthorized manipulations, and potential misuse. This paper aims to design and implement a secure, blockchain-based framework that blends AES (Advanced Encryption Standard) and RSA (Rivest–Shamir–Adleman) key management, which addresses these challenges. The aim is to guarantee strong data confidentiality by using symmetric encryption, and to use public-key cryptography for granular access control and secure key distribution. The proposed system uses Ethereum smart contracts to connect encrypted data references to a decentralized ledger, ensuring tamper resistance and auditability. In the proposed system, a Python-based FastAPI backend is responsible for data ingestion, cleaning, encryption, and blockchain interaction, while a React frontend can upload datasets, generate encryption keys, and retrieve access permissions. Modular microservices and well-defined APIs can seamlessly integrate various components, such as data processing scripts and on-chain contract logic, during development. The system's scalability is demonstrated by evaluating its performance against various dataset sizes, which involves metrics such as encryption overhead, blockchain transaction costs, and smart contract execution times. The practical usability of the system in actual scenarios is demonstrated through user acceptance testing, which is crucial for adoption in resource-limited environments. The results show the proposed crypto-enhanced blockchain framework can significantly enhance geospatial data security while still maintaining operational efficiency. Integration with zero-knowledge proofs may be explored in future work to enhance privacy, mitigate energy costs through alternative consensus algorithms, and enhance resilience in multi-network ecosystems through cross-chain interoperability.
As digital identity solutions become increasingly prevalent, the necessity for robust age verification mechanisms has emerged as a critical concern for a range of services, from online transactions to access to age-restricted content. Current age verification methods often fall short of accommodating the diverse standards across jurisdictions, leading to vulnerabilities and inconsistencies in user experience. One of the main objectives of this study is to identify and analyze in a systematic way existing age verification methods and the main relevant international regulatory frameworks. The Age Verification Profile by the European Commission is including and exploring Zero-Knowledge Proof-based solutions for age verification, which are also considered in the EUDI Wallet Architecture and Reference Framework. This approach not only minimizes data privacy risks but also facilitates seamless digital interactions across the European Union. This paper primarily aims to explore the critical role of the European Digital Identity Wallet Architecture and Reference Framework in age verification and demonstrate that the EUDI Wallet seeks to enhance the security and efficiency of online transactions by introducing robust age verification mechanisms that effectively balance user privacy, security, and compliance with various regulatory requirements while preventing unauthorized access to services with age restrictions, which is in line with the broader objectives of the European Digital Identity initiative. Furthermore, we examine the European Union's age verification approach via the EUDI Wallet and the U.S. framework approach, conducting a comparative analysis between them that highlights key differences in architectural design and legal underpinnings and emphasizes their advantages.
Crowd-sensing is considered a robust model for data collection, yet with challenges related to data availability and privacy. Traditional techniques such as data encryption and anonymization may not fully mitigate these issues, since anonymized data can still be traced back to individual users, and the volume of data generated can reveal user identities. This paper introduces a system that employs smart contracts and blockchain technology to manage crowd-sensing campaigns. The smart contract oversees user subscriptions, data encryption, and decentralized storage, creating a secure data marketplace. Incentive mechanisms within the smart contract promote user participation. Simulation results validate the system’s feasibility, emphasizing the importance of user engagement for data credibility and the impact of geographical data scarcity on rewards.
The rapid evolution of smart cities has led to transformative advancements through the integration of IoT devices, sensors, and data-driven systems, yet has simultaneously exposed critical vulnerabilities in cybersecurity, data integrity, and trust management. This research proposes a Decentralized Trust Framework that leverages blockchain technology, AI-driven threat detection, and a Lightweight Adaptive Proof-of-Stake (LA-PoS) consensus mechanism to address these challenges. The framework integrates three key layers: a Blockchain Layer for decentralized trust and immutability, a Cybersecurity Layer employing cryptographic standards and AI-based anomaly detection, and a Data Integrity Protocol Layer for real-time synchronization and tamper-proof data validation. Performance evaluations indicate the framework achieves a threefold increase in transaction throughput, a 30% reduction in latency, and enhanced energy efficiency compared to traditional blockchain systems. Security metrics highlight a 98.2% threat detection rate and a substantial reduction in false positives, while resource optimization nearly doubles IoT device battery life. The framework demonstrates applicability in critical smart city use cases, including smart traffic management, energy systems, and public safety, providing secure, scalable, and efficient solutions for urban infrastructures. Despite these advancements, challenges such as interoperability among heterogeneous systems, computational overhead for IoT devices, and policy adoption persist. Future research will focus on optimizing interoperability protocols, incorporating quantum-resistant cryptographic techniques, and extending the framework to emerging domains such as autonomous systems and smart healthcare. The proposed framework provides a robust foundation for building sustainable, resilient, and trustworthy urban ecosystems, bridging gaps in current smart city technologies.
Background: Cryptocurrency is a digital decentralized currency that enables peer-to-peer transactions without the involvement of intermediaries, using blockchain technology to ensure security and transparency. These emotions can help understand when and what behavioral intentions toward cryptocurrency adoption are necessary. These insights contribute to the growing literature on fintech adoption in emerging economies and provide valuable guidance for policymakers and investors formulating cryptocurrency regulations in Nepal. Objectives: It aims to investigate the influence of perceived usefulness, perceived ease of use, trust, and perceived risk constructs attached to an individual's intention to be involved in cryptocurrency transactions. It finally aims to study the relationships among these variables and their effect on cryptocurrency adoption in the Nepal context. Methods: The study uses a quantitative descriptive design and snowball sampling alone to extract information from cryptocurrency users in Nepal. A structured online questionnaire was used to gather 272 responses and analyzed using correlation and regression to investigate the significance of the proposed hypotheses. Results: Findings show that perceived usefulness, ease, or trust significantly and positively influence behavioral intention toward cryptocurrency adoption, while perceived risk harms adoption because users worry about market volatility, regulatory uncertainty, and security threats. Despite the government's legal restrictions, many Nepalese citizens are still involved in cryptocurrency transactions, seeing it as a source of financial benefit and investment opportunity. Conclusion: The study attests that perceived usefulness, perceived ease of use, and trust motivate behavior toward adopting cryptocurrency, while perceived risk provides a barrier. This enlightens policymakers on balanced regulatory measures that address risks while encouraging innovation in digital finance. These findings would provide valuable implications for policymakers, financial institutions, and technology developers in outlining the future of cryptocurrency regulation and adoption strategies. JEL Classification: D14, E42, G41
Blockchain technology presents transformative opportunities for secure personal data sharing, particularly in healthcare, finance, and identity management. However, its widespread adoption is constrained by challenges such as limited scalability, privacy concerns, and conflicts with regulatory frameworks like the General Data Protection Regulation (GDPR). This study introduces a novel hybrid framework that integrates the InterPlanetary File System (IPFS) for off-chain storage with Zero-Knowledge Proofs (ZKPs) to enhance privacy, ensure regulatory compliance, and reduce on-chain storage demands. Employing a Design Science Research (DSR) methodology, the framework was developed and validated using Ethereum and Hyperledger Fabric, guided by insights from a systematic review of 180 studies from 2018 to 2023. Empirical evaluations revealed a 75% reduction in blockchain storage, 98% GDPR compliance, and zk-SNARK proof verification times below one second. The framework also enables GDPR-compliant erasure by removing encrypted off-chain data while preserving on-chain auditability. Despite challenges such as IPFS latency and trusted setup complexities, the solution offers a scalable and privacy-preserving architecture applicable to real-world domains, especially in privacy-critical environments like healthcare and finance by resolving blockchain’s GDPR compliance paradox.
Syed Abrar Ahmed, Ricardo Correia, Anderson Oliveira do Carmo, Henrique Martins
Increasingly, across geographies, citizens are requiring access to and control of their health data. This paper examines the "Logging Component" proposed by the European Health Data Space (EHDS) regulation and its crucial role in facilitating secure and transparent access to electronic health records (EHR) and health data. We analysed the proposal for the five elements of the Logging Component (LC): identification of data accessors, identification of data subjects, categorisation of accessed data, temporal logging, and data origin tracking. Explored how these elements contribute towards enhanced accountability and compliance in health data management. We experimented with distributed ledger technology (DLT) to support the "data origin tracking element", reaching the demonstration level which can be presented. We used hybrid DLT to develop a system for immutable storage of access logs, and for using smart contracts to maintain a self-governing decentralised access control list (ACL) directly integrated with EHR and PHR systems. We found that the LC is more than a regulatory requirement. It can serve as a framework for the integration of advanced technologies, e.g. DLT and others, increasingly mature and potentially foundational to building new networks of trust among stakeholders, while ensuring data privacy in cross-border and intra-border healthcare scenarios. The study also identified shortcomings of the LC, such as the absence of "purpose logging", which was conceptualised and proposed. This study contributes to the understanding of how logging mechanisms can enhance transparency and accountability in electronic health record systems within the European healthcare landscape, but with potential usefulness for the "Global EHR". In conclusion, our findings suggest that the successful implementation of the five elements of the Logging Component are mandatory and can benefit from mature advance technologies, but the sixth element proposed by us would be critical for achieving the EHDS's broader objectives of harmonised health data sharing in Europe and beyond while maintaining robust security standards.
The article presents a comprehensive analysis of the transition from traditional centralized digital identity models to an innovative decentralized paradigm based on block-chain technologies and zero-knowledge proofs (ZKP). It highlights the fundamental problems of existing systems that rely on centralized registries, passwords, and social logins. Such approaches create significant vulnerabilities, including risks of data breaches, mass surveillance, and manipulation, as centralized intermediaries act as sole controllers of personal information, depriving users of control over their data. In response to these challenges, the article discusses the concept of Decentralized Identity (DID). This model enables individuals to own, store, and control their digital credentials independently, without involving intermediaries. The key technological components of this ecosystem include Verifiable Credentials (VC), Digital ID Wallets, and Decentralized Identifiers (DID), which are typically stored on a block-chain to ensure immutability and security. A triadic trust model involving the Issuer, Holder, and Verifier is described, allowing data verification without direct contact with the issuing organization. Special attention is given to the concept of Self-Sovereign Identity (SSI) as a specific philosophy within DID that emphasizes user autonomy, data minimization, and privacy by design. Unlike the broader DID concept, in the SSI model, the user makes the final decision regarding the disclosure of their data. A central technology ensuring privacy in decentralized systems is zero-knowledge proofs (ZKP). ZKP allow the validation of the truthfulness of a statement without revealing the underlying information. The article provides a detailed analysis of the benefits of using ZKP in the context of DID, including selective attribute disclosure (e.g., proving legal age without revealing the date of birth), minimizing the amount of shared data, preventing correlation and user activity tracking, as well as creating reputation systems that preserve anonymity. Practical application scenarios such as private electronic voting and confidential medical data protection are examined. The paper also addresses standardization, which is key to ensuring compatibility and widespread adoption of DID solutions. Leading initiatives such as W3C Verifiable Credentials, the Decentralized Identity Foundation (DIF), and projects like Hyperledger Indy and Aries are mentioned. Examples of advanced implementations already in use are provided: Polygon’s zkKYC for private verification in DeFi, the Sismo protocol for creating anonymous reputation badges in Web3, and Evernym’s SSI platform based on Hyperledger Indy. In conclusion, it is emphasized that the combination of DID and ZKP forms a new paradigm for digital identity management focused on security and user autonomy. Despite challenges related to usability complexity, key loss risk, and legal uncertainty, the technology is actively evolving and moving from conceptual to practical application, which may eventually become the foundation for a global sovereign digital identity.
BACKGROUND The integration of digital health tools and algorithms in mental healthcare brings a transformative era where technologies like digital phenotyping, affective computing, and computational behavioral analysis are used to passively collect and analyze data from patients outside clinical settings. These "computer perception" (CP) technologies offer new insights into symptom manifestation in daily life while generating large volumes of potentially sensitive data that raise significant data privacy concerns requiring high levels of patient awareness and consent. Empirical research is lacking into stakeholder understandings and perspective towards the collection, management and protection of these data types. OBJECTIVE This study aimed to explore key stakeholder perspectives on the sensitivity of CP data, trust in existing data protections, willingness to share CP data externally, and desire for transparency of CP data transactions outside of the clinical space. METHODS As part of a larger, multi-site study, we conducted qualitative interviews (n=40) via Zoom with 20 adolescents (aged 12-17 years) familiar with CP tools and their caregivers (n=20). Interviews consisted of a series of open-ended questions regarding stakeholders’ perspectives on privacy, data security, and the use and exchange of CP data. We developed a qualitative codebook to identify and label thematic patterns in responses to questions addressing the topics above, using thematic content analysis to inductively identify themes. Each interview was coded by merging work from at least two separate coders, and several team members contributed to qualitative analysis. RESULTS Most adolescents and caregivers viewed CP data as highly sensitive and expressed a reluctance to share these data beyond their clinical teams. While many participants expressed trust in existing data protections to protect CP data, they often misunderstood or overestimated the extent of protections like HIPAA to safeguard CP data. CONCLUSIONS Our findings underscore the critical need for clear and effective patient communication and education about the risks, benefits, and protections associated with CP data through informed consent protocols. To promote greater visibility, understanding, and trust (when justified) in digital tools that have strong promise to promote patient health, we recommend five key strategies, including: (1) educating patients on the limitations of existing data protections; (2) conducting targeted research, including forensic analyses, into secondary data exchanges and to identify privacy breaches or reidentification risks; (3) enacting regulations that mandate greater transparency in health data transactions; (4) implementing computational mechanisms, such as distributed ledger technologies, to enhance data traceability and auditability; and (5) adopting dynamic consent models that allow patients to continuously manage and update their consent preferences.
This study investigates the integration of the Portuguese Citizen’s Card authentication with Hyperledger Fabric blockchain technology, addressing the challenge of bridging traditional government-issued digital identities with blockchain-based systems, particularly focusing on reducing barriers to Web3 adoption for users unfamiliar with decentralized technologies. The proposed solution leverages the Autenticação.gov Software Development Kit (SDK), developed by the Portuguese Agency for Administrative Modernization (AMA) to create a secure bridge between the Citizen’s Card authentication system and Hyperledger Fabric's permissioned blockchain framework. The study examines how this approach can facilitate the development of transparent, tamper-proof authentication systems suitable for critical applications such as e-voting and digital government services, and also feasible for on-premises systems. The findings suggest that integrating existing digital identity systems with blockchain technology can promote wider acceptance of decentralized solutions while maintaining security, privacy, and accessibility standards required for public sector applications.
Nikos Papatheodorou, George Hatzivasilis, Nikos Papadakis
Self-sovereign identity (SSI) is an emerging model for digital identity management that empowers individuals to control their credentials without reliance on centralized authorities. This work presents YouGovern, a blockchain-based SSI system deployed on Binance Smart Chain (BSC) and compliant with W3C Decentralized Identifier (DID) standards. The architecture includes smart contracts for access control, decentralized storage using the Inter Planetary File System (IPFS), and long-term persistence via Web3.Storage. YouGovern enables users to register, share, and revoke identities while preserving privacy and auditability. The system supports role-based permissions, verifiable claims, and cryptographic key rotation. Performance was evaluated using Ganache and Hardhat under controlled stress tests, measuring transaction latency, throughput, and gas efficiency. Results indicate an average DID registration latency of 0.94 s and a peak throughput of 12.5 transactions per second. Compared to existing SSI systems like Sovrin and uPort, YouGovern offers improved revocation handling, lower operational costs, and seamless integration with decentralized storage. The system is designed for portability and real-world deployment in academic, municipal, or governmental settings.