Security and Privacy in Distributed and Trustless Systems

Topic Information

Dear Colleagues,

Distributed and trustless systems are becoming a foundational paradigm for modern data-driven applications, enabling large-scale collaboration without relying on centralized authorities or fully trusted intermediaries. Such systems, including blockchain networks, federated learning frameworks, decentralized AI, and multi-agent platforms, introduce new opportunities for secure data sharing and autonomous coordination, while simultaneously raising critical challenges in data security and privacy protection.

This Topic aims to explore recent advances in security- and privacy-preserving techniques for distributed and trustless environments. We invite contributions that investigate theoretical foundations, algorithmic designs, system architectures, and practical deployments addressing threats such as data leakage, inference attacks, malicious participants, and trust misalignment. Topics of interest include, but are not limited to, cryptographic protocols, secure and verifiable computation, privacy-preserving machine learning, decentralized data governance, and trustworthy AI systems. By bringing together interdisciplinary research from security, distributed systems, and artificial intelligence, this Topic seeks to provide a comprehensive view of emerging challenges and solutions for building secure, privacy-aware, and trustworthy distributed systems.

Dr. Longxiang Gao
Dr. Bruce Gu
Topic Editors

Keywords

Participating Journals

Journal Name	Impact Factor	CiteScore	Launched Year	First Decision (median)	APC
Algorithms algorithms	2.6	5.4	2008	17.6 Days	CHF 1800	Submit
Applied Sciences applsci	2.9	6.1	2011	15 Days	CHF 2400	Submit
Blockchains blockchains	-	-	2023	23.8 Days	CHF 1000	Submit
Computers computers	5.2	9.1	2012	15.4 Days	CHF 1800	Submit
Cryptography cryptography	2.4	6.4	2017	19.9 Days	CHF 1800	Submit
Future Internet futureinternet	4.6	10.0	2009	15 Days	CHF 1800	Submit
Information information	4.3	8.2	2010	18.7 Days	CHF 1800	Submit
Network network	3.7	8.0	2021	23.2 Days	CHF 1200	Submit

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Published Papers (7 papers)

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All Applied Sciences Future Internet Information Algorithms Computers Blockchains Cryptography Network

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31 pages, 2446 KB  

Open AccessArticle

A Batch Identity-Based Encryption Scheme for Object-Level Authorization of Smart Tourism Data

by Lixia Sun, Dengshuo Zhu, Changgen Peng, Chenran Xiong and Chuanda Cai

Cryptography 2026, 10(5), 67; https://doi.org/10.3390/cryptography10050067 - 10 Sep 2026

Viewed by 207

Abstract

When smart tourism data are shared across scenic areas, hotels, transportation platforms, and regulatory authorities, existing access control schemes often struggle to simultaneously support batch authorization for data object sets, multi-authority collaboration, revocation-version binding, and low-latency online encryption. To address these challenges, this [...] Read more.

When smart tourism data are shared across scenic areas, hotels, transportation platforms, and regulatory authorities, existing access control schemes often struggle to simultaneously support batch authorization for data object sets, multi-authority collaboration, revocation-version binding, and low-latency online encryption. To address these challenges, this paper proposes a Threshold Distributed Batch Identity-Based Encryption scheme for object-level authorization of smart tourism data, termed TD-BIBE. The scheme jointly binds data object identities, batch labels, authorization periods, revocation versions, and authorization contexts to ciphertext access control. It employs Shamir secret sharing for threshold distributed key generation, preventing any single authorization authority from obtaining the complete master secret key. Set-polynomial digests and membership witnesses are used to support batch authorization over identity sets and object-level membership verification. A revocation-version binding mechanism restricts the validity scope of authorization materials, while an offline/online encryption structure reduces the online computational overhead of data providers. Formal security analyses are conducted in the random oracle model with respect to data confidentiality, object-level authorization, batch-label binding, revocation-version binding, resistance to unauthorized key-combination attacks, and threshold authorization security. Experimental results demonstrate that TD-BIBE is suitable for cross-departmental, multi-object, and on-demand data sharing in smart tourism scenarios. Full article

(This article belongs to the Topic Security and Privacy in Distributed and Trustless Systems)

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30 pages, 2562 KB  

Open AccessArticle

A Hierarchical Benchmarking Framework for Homomorphic Encryption-Based Aggregation and Validation Using Real Smart Meter Data

by Aiman Ahmad Shivani, Marzia Zaman, Pirathayini Srikantha, Darshana Upadhyay and Kshirasagar Naik

Cryptography 2026, 10(5), 63; https://doi.org/10.3390/cryptography10050063 - 1 Sep 2026

Viewed by 262

Abstract

Homomorphic encryption (HE) enables computation on encrypted data and has emerged as a promising technology for privacy-preserving distributed analytics. However, the practical deployment of HE in large-scale hierarchical systems requires a thorough understanding of its computational overhead, scalability, and accuracy. This paper presents [...] Read more.

Homomorphic encryption (HE) enables computation on encrypted data and has emerged as a promising technology for privacy-preserving distributed analytics. However, the practical deployment of HE in large-scale hierarchical systems requires a thorough understanding of its computational overhead, scalability, and accuracy. This paper presents a generic hierarchical benchmarking framework for systematically evaluating homomorphic encryption schemes in multi-level aggregation environments. The framework supports configurable aggregation topologies, detailed operation-level profiling, and multiple encryption backends, enabling consistent and reproducible performance analysis across node-, cluster-, and global-level aggregation stages. Using the proposed framework, we conduct a comparative evaluation of the Brakerski/Fan–Vercauteren (BFV) and Cheon–Kim–Kim–Song (CKKS) schemes under identical workloads. Experimental results show that CKKS consistently outperforms BFV, achieving a 44.3% reduction in aggregation latency and a 24.6% reduction in decryption latency. For the tested encoding and parameter settings, CKKS delivers significantly lower numerical error, reducing the mean absolute error from $3.21\times {10}^{-3}$ to $5.91\times {10}^{-10}$. The proposed framework offers a reusable and extensible platform for evaluating emerging HE schemes and privacy-preserving analytics applications, thereby supporting future research and deployment of secure distributed data processing systems. Full article

(This article belongs to the Topic Security and Privacy in Distributed and Trustless Systems)

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24 pages, 729 KB  

Open AccessFeature PaperArticle

A Scalable Blockchain Architecture for Digital Certificate Management Using Microservice-Based Processing and Batch Anchoring

by Shweta H. Bhatia and Ravirajsinh S. Vaghela

Blockchains 2026, 4(3), 15; https://doi.org/10.3390/blockchains4030015 - 30 Aug 2026

Viewed by 255

Abstract

Blockchain-based infrastructures have increasingly been adopted for secure and tamper-resistant management of academic credentials. Despite the advantages offered by blockchain technology, existing blockchain-based credential management systems continue to face several scalability challenges, particularly in terms of limited transaction throughput, increased confirmation delays, and [...] Read more.

Blockchain-based infrastructures have increasingly been adopted for secure and tamper-resistant management of academic credentials. Despite the advantages offered by blockchain technology, existing blockchain-based credential management systems continue to face several scalability challenges, particularly in terms of limited transaction throughput, increased confirmation delays, and continuous ledger growth resulting from storing individual certificates as separate blockchain transactions. These limitations become more evident in large-scale educational environments where universities and affiliated institutions are required to issue and verify thousands of digital credentials within limited operational timeframes. To overcome these challenges, this work introduces a performance-optimized blockchain architecture for scalable academic credential management. The proposed framework separates certificate preprocessing from blockchain anchoring by incorporating a microservice-based parallel processing layer, Merkle-tree-based batch anchoring, and distributed off-chain storage mechanisms. This modular design reduces blockchain transaction overhead while maintaining the security, integrity, auditability, and verifiability of academic credentials. To assess system performance, a formal analytical model integrating queueing theory and blockchain performance characteristics is developed to characterize system behavior under varying workload conditions. By enabling multiple certificates to be aggregated and committed through a single blockchain transaction, the proposed architecture improves throughput and enhances storage efficiency compared to conventional blockchain-based approaches. Analytical evaluation demonstrates that the system can sustain high certificate issuance rates while maintaining low confirmation latency and minimal on-chain storage growth. Full article

(This article belongs to the Topic Security and Privacy in Distributed and Trustless Systems)

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37 pages, 2531 KB  

Open AccessArticle

PEUAP-W3: A Formally Verified Zero-Knowledge Authentication Protocol for Web 3.0 Unifying Conditional Biometric Binding, Threshold-Accountable Anonymity, and Self-Sovereign Identity

by Adarsh S. V. Nair and Rathnakar Achary

Computers 2026, 15(9), 563; https://doi.org/10.3390/computers15090563 - 27 Aug 2026

Viewed by 343

Abstract

Authentication in Web 3.0 faces a structural conflict. Systems that offer full anonymity leave no lawful way to identify a malicious actor. Systems built for accountability expose a persistent wallet address to blockchain-graph analysis, or fall back on centralized key recovery. Existing designs [...] Read more.

Authentication in Web 3.0 faces a structural conflict. Systems that offer full anonymity leave no lawful way to identify a malicious actor. Systems built for accountability expose a persistent wallet address to blockchain-graph analysis, or fall back on centralized key recovery. Existing designs solve one side of this conflict at the cost of the other. This paper presents PEUAP-W3, a Privacy-Enhanced and User-centric Authentication Protocol. Its contribution is the integration of five established components into a single deployed and formally analyzed system. A Circom 2 circuit of 1579 Groth16 constraints proves four facts in a single 192-byte on-chain proof: knowledge of an opening of the session credential commitment, an SpO₂ value inside an 85–100% band, single-use nonce binding, and HMAC integrity. Shamir (k = 2, n = 3) sharing distributes the identity payload across three independent relays. The coordinator reconstructs an identity only after a threshold vote has been recorded on chain. Credentials are issued as W3C Verifiable Credentials 2.0 in did:key form. Four Solidity contracts verify the proof on Ethereum Sepolia. Verification costs about 241,000 gas and takes roughly 3 ms. ProVerif and Scyther find no attack under the Dolev–Yao model. A concurrency sweep to 500 simultaneous requests completes 1191 requests with zero failures at about 15.4 requests per second. A behavioral gate screens commodity abuse as a supplementary control; it is not treated as a security boundary. Against a nine-property framework, PEUAP-W3 satisfies six properties. Three remain conditional and are not verified in the current deployment: biological-origin assurance and digital replay prevention, both of which need an attested sensor; and GDPR erasure equivalence. Here, formally verified refers to the protocol models and theorems, not to the complete deployed software. Full article

(This article belongs to the Topic Security and Privacy in Distributed and Trustless Systems)

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48 pages, 9266 KB  

Open AccessArticle

SDAP-K: A Kerberos-Assisted Secure Data Auditing Protocol for Cloud Storage

by Thangavel Murugan, Nasurudeen Ahamed Noor Mohamed Badusha, Priyan Malarvizhi Kumar and Varalakshmi Perumal

Future Internet 2026, 18(8), 411; https://doi.org/10.3390/fi18080411 - 3 Aug 2026

Viewed by 383

Abstract

Cloud storage services have become a fundamental component of modern computing infrastructures, enabling scalable and cost-effective data management. However, outsourcing data to remote cloud servers introduces significant security challenges, particularly in ensuring data integrity, secure access control, and efficient auditing of stored information. [...] Read more.

Cloud storage services have become a fundamental component of modern computing infrastructures, enabling scalable and cost-effective data management. However, outsourcing data to remote cloud servers introduces significant security challenges, particularly in ensuring data integrity, secure access control, and efficient auditing of stored information. Existing cloud auditing schemes primarily focus on integrity verification and often rely on trusted third-party auditors, leading to additional trust assumptions, communication overhead, and metadata management complexity. To address these limitations, this research presents a Kerberos-Assisted Secure Data Auditing Protocol (SDAP-K) that integrates authenticated service exchange with lightweight integrity verification for outsourced cloud storage. The proposed framework employs Kerberos-based mutual authentication and ticket-driven access control to establish secure communication among the Data Owner, Authentication Server, Metadata Server, and Cloud Data Server. To verify storage correctness, an N-ary hash tree with the Modified Murmur hash algorithm is used to enable efficient file- and block-level auditing without requiring a trusted third-party auditor. The framework further incorporates metadata-assisted auditing, dynamic data operations, and an error localization and recovery mechanism that identifies and restores corrupted data blocks. Security analysis demonstrates that the proposed protocol mitigates unauthorized access, replay attacks, impersonation attempts, and malicious data modification. Experimental results indicate that SDAP-K reduces storage execution time by 18.6%, retrieval time by 24.3%, update time by 21.8%, file-level auditing overhead by 31.5%, and block-level auditing latency by 36.2% compared with state-of-the-art research, while eliminating the need for a trusted third-party auditor. The results indicate that the proposed framework offers a practical, lightweight, and reliable solution for secure cloud data auditing in enterprise cloud storage environments. Full article

(This article belongs to the Topic Security and Privacy in Distributed and Trustless Systems)

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29 pages, 1078 KB  

Open AccessArticle

DAO-TDS: Decentralized Autonomous Trusted Data Space for Global Data Circulation

by Yongjian Wang and Aibo Song

Computers 2026, 15(8), 482; https://doi.org/10.3390/computers15080482 - 29 Jul 2026

Viewed by 832

Abstract

Trusted Data Spaces (TDSs) have emerged as the core infrastructure for secure, privacy-preserving data circulation across industries and jurisdictions. However, state-of-the-art TDS implementations suffer from centralized platform monopoly, rigid cross-border governance failure, unfair value distribution, and poor scalability for global-scale collaboration. This paper [...] Read more.

Trusted Data Spaces (TDSs) have emerged as the core infrastructure for secure, privacy-preserving data circulation across industries and jurisdictions. However, state-of-the-art TDS implementations suffer from centralized platform monopoly, rigid cross-border governance failure, unfair value distribution, and poor scalability for global-scale collaboration. This paper proposes DAO-TDS, a novel decentralized autonomous trusted data space paradigm that enables centerless, cryptography-governed, and value-closed-loop data circulation. We make three core contributions: (1) We formalize the first anti-monopoly, incentive-compatible game-theoretic model for distributed TDS governance, with rigorous provable security guarantees; (2) we design an original Proof of Data Contribution (PoDC) consensus mechanism and a post-quantum secure Crypto-DAO governance protocol, with formal security proofs under the Universal Composability (UC) framework; (3) we implement a full prototype of DAO-TDS and conduct comprehensive, reproducible evaluations, showing that it supports 10,000+ distributed nodes with >12,000 TPS and <2 s 99th-percentile confirmation latency, while delivering >80% of generated value to data contributors (vs. <50% in centralized platforms). While the proposed paradigm demonstrates strong performance and security guarantees, it still faces challenges in adaptive cross-jurisdictional compliance and lightweight edge node deployment, which require further investigation. Full article

(This article belongs to the Topic Security and Privacy in Distributed and Trustless Systems)

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24 pages, 2065 KB  

Open AccessArticle

A Hybrid ABAC–RpBAC Framework for Enhancing PoS Consensus Against Sybil Attacks

by Mohammed Al Qurashi and Ibtihaj Al Qarni

Future Internet 2026, 18(6), 276; https://doi.org/10.3390/fi18060276 - 22 May 2026

Viewed by 548

Abstract

Sybil attacks remain a primary challenge for Proof-of-Stake (PoS) blockchain systems, as low-cost identity creation can distort validator participation and limit consensus reliability. This study proposes a hybrid participation–governance framework that integrates Attribute-Based Access Control (ABAC) and Reputation-Based Access Control (RpBAC) with a [...] Read more.

Sybil attacks remain a primary challenge for Proof-of-Stake (PoS) blockchain systems, as low-cost identity creation can distort validator participation and limit consensus reliability. This study proposes a hybrid participation–governance framework that integrates Attribute-Based Access Control (ABAC) and Reputation-Based Access Control (RpBAC) with a trust-based PoS workflow to reduce the influence of suspicious identities during validator selection and block validation. The proposed framework also incorporates graylisting and dynamic reward–penalty updates to support adaptive participation control. The strategy was evaluated in a simulation environment informed by Ethereum-derived block metadata, using network sizes ranging from 100 to 1000 nodes and Sybil attack ratios of 30%, 40%, and 50%. Its performance was compared with PoS-only and PoS + ABAC baselines using both security and performance indicators. The results show that the full ABAC + RpBAC configuration achieved the strongest and most stable security performance across the evaluated settings while introducing additional overhead at larger network sizes. These findings suggest that combining policy-based eligibility control with behavior-based reputation control strengthens the resilience against Sybil in PoS-like blockchain environments. However, this improvement requires a measurable trade-off between security and performance. Full article

(This article belongs to the Topic Security and Privacy in Distributed and Trustless Systems)

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