Marco Scarpa, Mohammad Sadeghzadeh, Saeed Javanmardi, Bahareh Pahlevanzadeh · 5 authors
Blockchain provides secure and decentralized data storage. Normal blockchains permanently store data. Mutable blockchains allow users to change data, but this reduces tamper resistance. This paper tests both methods in PaB-PIF, a hybrid architecture for IoT-Fog networks. Our design uses an immutable mainchain in the cloud layer and mutable sidechains in the fog layer. We analyze throughput, latency, and tamper resistance using math models and simulations. Results show that blockchain greatly improves network security. Without blockchain, the network has zero tamper resistance. The mutable blockchain in the fog layer has a tamper resistance of 0.58. The immutable blockchain in the cloud layer reaches 0.99. However, this extra security increases latency and reduces throughput. The mutable blockchain has lower latency, so it is a good fit for the fog layer. The immutable blockchain provides maximum security, which is best for the cloud layer. This trade-off works well for IoT systems like the Internet of Vehicles, where data integrity and legal rules are essential. We also compare PaB-PIF with an IoT-Fog network that has no blockchain.
Kapil K. Jajulwar, Priya Dasarwar, Uma Yadav, Bhakti Prasad Thakre · 6 authors
Blockchain consensus mechanisms are important to ensure the safe validation of transactions. However, the limitations of high computational complexity, energy consumption, and mining latency restrict the scalability of blockchain in large-scale IP-based and wireless network environments. Current methods mainly rely on single optimization methods without jointly optimizing miner selection and hash computation, resulting in inferior performance under dynamic network conditions. To fill this gap, this study presents a new hybrid bioinspired optimization framework for efficient blockchain mining, integrating Genetic Algorithm (GA), Firefly optimization, and Particle Swarm Optimization (PSO) into a unified architecture to take advantage of their complementary strengths. The proposed method uses both historical and real-time performance metrics to determine the best mining nodes. The Firefly algorithm is used to optimize the selection of hash ranges to reduce CPU workload. PSO is used to select high-performance neighboring nodes for collaborative mining. The model is implemented using the NS-2 simulator and tested over a network of 1000 wireless nodes under different consensus protocols. The experimental results illustrate 4.3% decrease in computational complexity, 4% decrease in energy consumption, and 5% decrease in mining delay. The model further reduces mining complexity by up to 34.2% and reduces the energy utilization from 24.5% to 16.6%, demonstrating its effectiveness for scalable and energy-efficient blockchain deployment.
Blockchain interoperability remains a major challenge because heterogeneous blockchain networks cannot securely and efficiently exchange cross-chain data and transactions. Existing interoperability solutions often rely on central relays or trusted intermediaries, creating security vulnerabilities, limited fault tolerance, and a single point of failure. To address these limitations, this paper proposes VeriMesh, a decentralised mesh-based interoperability framework that combines trust-adaptive routing, multi-path relay verification, and Zero-Knowledge Proof (ZKP)-based validation for secure cross-chain communication. VeriMesh models relay nodes as a trust-weighted graph in which routing decisions dynamically adapt based on node behaviour and delivery reliability. Multi-path routing improves resilience against adversarial relay nodes, while transport-layer ZKP verification enables privacy-preserving validation without exposing sensitive information. The framework was implemented using Python relay nodes, Solidity smart contracts, and an Ethereum (Ganache) environment. Experimental evaluation using structured event-driven workloads demonstrated stable latency below 34 ms and delivery success rates above 85% up to 40% malicious node presence. Comparative evaluation against single-path and random multi-path relay baselines showed improved fault tolerance and routing reliability. The results demonstrate favourable scalability and robustness within the evaluated network range ( N = 10–30), while larger-scale evaluation remains future work. All experiments were conducted in a controlled local Ganache blockchain environment rather than on a public Ethereum testnet or mainnet, so the reported latency, gas, and delivery figures characterise protocol-layer behaviour under controlled conditions and should not yet be interpreted as representative of performance under public-network conditions such as real gas markets, block propagation delays, or network congestion.
Cüneyt Gürcan Akçora, Murat Kantarcioglu, Yulia R. Gel
This chapter introduces blockchain network structures in both UTXO- and account-based systems. It begins with Bitcoin’s transaction and address graphs, showing how Satoshi Nakamoto’s design defines network topology and enables modeling through transaction graphs, address graphs, and chainlets. Privacy coins like Monero and Zcash extend this framework with ring signatures and zero-knowledge proofs that obscure data but still permit partial inference. Ethereum shifts focus to account-based networks, covering coin and token transactions, contract interactions, and trace analysis. Ripple concludes the chapter with credit networks built on trust lines and path-based settlements, showing how global credit flows can be modeled graphically.
The set reconciliation problem, that consists in bringing two or more replicas of a set into agreement is present in all databases, distributed ledgers and any large scale synchronization systems.While the two party case is well studied, the multiparty one exposes a large design space of protocols whose communication cost varies drastically with topology, replica count and the level of similarity.A very slow space to search on by hand.This thesis investigates the use of an autonomous agent loop as a research tool to navigate that specific design space.This means using an agent to iteratively propose, implement and evaluate reconciliation protocols against a single measurable objective until convergence is achieved.In this case, the objective was the total bytes transmitted, including state and metadata, taken as a geometric mean over an evaluation matrix with eighteen cells and three seeds.The search yielded MultiReplica, a topology dispatched protocol that combines all neighbor Bloom filter exchange on star and tree topologies with pairwise distance doubling on chord and that reduces communication cost by roughly 30 % relative to the strongest hand designed baseline while scaling to replica counts at which the baselines exhaust memory.The contribution is twofold.On one side the discovered protocol itself and a reproducible demonstration that an autonomous agent loop can serve as a credible, auditable method for distributed systems protocol research.
Patikiri Arachchige Don Shehan Nilmantha Wijesekara, Kalupahana Liyanage Kushan Sudheera, Harsha S. Gardiyawasam Pussewalage, Geeth P. Wijesiri N. B. A
Incorporating connected mobility data into decision-making brings about significant data security and privacy challenges in next generation transportation systems. The problem becomes worse when the raw traffic data stream contains commuters' sensitive information that could be extracted by successful attackers. The challenges of data security and privacy must be addressed in order to create a secure information sharing environment for next generation transportation systems. ☐ Blockchain technology, which provides a tamper-resistant journal of state transition events, becomes an ideal candidate for realizing the goals of creating secure information sharing frameworks. However, existing blockchain technology and deployments also have their limitations, especially in data privacy. Because the saved data on the blockchain ledger can not be altered, we do not want to make sensitive information publicly available or record false information permanently without an authentication protocol. ☐ Innovations are needed to overcome barriers in blockchain technology for enabling secure and privacy-preserving information sharing in next generation transportation systems. This Ph.D. dissertation introduces three main innovations: (1) a zero-knowledge and Byzantine fault tolerant consensus that brings privacy-preserving to the blockchain consensus level for verifying and processing transactions, Chapter 2; (2) novel privacy-preserving authentication schemes for blockchain networks based on zero-knowledge proofs to increase security and safety in traffic management, autonomous truck fleets and ridesharing, Chapters 3, 4 and 5; and (3) blockchain-inspired architecture designs with access control policies that protect huge amounts of traffic and users' data and log access events into blockchain for traceability and accountability, Chapters 4 and 5.
Web3Compass is presented as a novel search engine tailored to the decentralized Web, integrating multiple blockchain-based name services (ENS, UNS, BNB NS) and content storage networks (IPFS, Arweave, Swarm). Our work describes a real-time monitoring architecture: blockchain registries are queried continuously for new domain registrations and updates, content hashes (e.g. IPFS CIDs) are retrieved and fetched, and website data is parsed and indexed for keyword search. We emphasize the system’s novelty in unifying diverse name systems and content networks under one private search interface. A comprehensive literature review covers previous decentralized search efforts (e.g. DEWS 1, DeScan 2, Krypton 3), blockchain naming services (Namecoin 4, ENS 5, Unstoppable 6, Space ID’s .bnb 7), and content- addressed storage (IPFS 8, Arweave 9, Swarm 10). We include an architecture diagram and discuss implementation details (event log watchers, IPFS HTTP retrieval, indexing pipeline, privacy layers). Evaluation uses scalability and latency metrics, compares with existing solutions, and includes ethical/privacy analysis (e.g. query privacy via Hexens 11, censorship resistance 4). Our results show that real-time blockchain- based domain resolution is feasible and complements Web3 infrastructure, while highlighting trade-offs in data completeness and user privacy.
This chapter addresses how getting data privacy in the world of centralised identification systems today is a myth because of its many problems, the primary one being data control by one single entity. Self-Sovereign Identity (SSI) is a model that allows its utilisers complete control over their data privacy and security. This paper gives an overview of developing such a model over a private blockchain network using several Hyperledger frameworks, which are majorly open source. Hyperledger Indy is crucial as it is an open-source public decentralised distributed ledger technology (DLT). Hyperledger Aries is used to interact with nodes, access them, and read and write data on the ledger. Hyperledger Ursa is used to avoid the double spending problem by employing blockchain cryptography.
Blockchain Technology is a Distributed Ledger Technology (DLT) where the data (digital information) is stored in multiple computers and not in a centralized one [1]. Each system would store a copy of the distributed ledger to avoid pitfalls. The information persists as blocks and gets updated simultaneously on all environments after being validated. Four main types of Blockchain, as described: private/permissioned, public/permissionless, hybrid, and consortium [2]. Corda is an open-source platform of a distributed ledger founded by R3 Consortium (R3CEV LLC). DLT is based on peer-to-peer connections with an agreement, and it is not part of the public. Corda architecture is non-native to cryptocurrencies. The platform is based on top of the Java Virtual Machine (JVM), written in Kotlin. Overall, it explains how Corda can be implemented in a wide range of industries with private/permissioned networks. Earlier, blockchain technology was public and permissionless, which posed a little challenge to many industries to adapt, even in the Supply Chain Management system (SCM) and healthcare. Corda is an open-source and DLT concept with private and permissioned features that make it easy to use in industries like SCM, and how that can be achieved.
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.
Rithika S, Thrisha S, Uma Mageshwari M, Vaishali D · 5 authors
Peer-to-peer (P2P) interaction forms a foundational layer of Web3 ecosystems, enabling participants to exchange data directly without depending on centralized brokers. In practical deployments, however, end-to-end reachability is often obstructed by network address translation, firewalls, and transient routing paths, which pushes architects toward the use of intermediate relay nodes. Unfortunately, relays that behave inconsistently or act maliciously can introduce a range of undesirable effects, including dropped packets, elevated latency, selective forwarding, and denial-of-service conditions. To mitigate these risks, this work presents a reputation-aware relay selection framework that lever-ages a blockchain substrate to govern trust. Every participant in the overlay is issued a cryptographic identity; the quality of service delivered by each relay is then tracked at runtime through metrics such as delivery ratio, round-trip delay, and transmission failure rate. A smart contract layer aggregates these observations into a dynamic reputation score that is recorded on an immutable ledger. When a communication session is being established, relays with higher reputation are preferred, while those exhibiting suspicious or degraded behavior are deprioritized or excluded. Experimental results indicate that, compared with conventional relay-selection strategies, the proposed approach delivers higher reliability, lower effective latency, and stronger resistance to malicious participation, making it a practical candidate for secure Web3 P2P communication.
Blockchain systems rely on architectural design choices and consensus protocols to establish decentralized trust in distributed environments. This paper presents a focused survey of blockchain architecture and protocol evolution, emphasizing structural components, peer-to-peer networking, consensus mechanisms, forking models, and security-scalability trade-offs. Core elements such as blocks, cryptographic hashing, distributed ledgers, node roles, transaction propagation, and validation processes are examined to explain how integrity and immutability are maintained. Major consensus mechanisms, including Proof of Work (PoW), Proof of Stake (PoS), Practical Byzantine Fault Tolerance (PBFT), and Proof of Authority (PoA), are comparatively analyzed with respect to decentralization, throughput, finality, energy consumption, and deployment context. The paper also examines blockchain forking as a mechanism for protocol evolution and governance. By distinguishing protocol-level concerns from application-level adoption, this survey provides a technical foundation for evaluating blockchain systems and identifies open challenges in scalability, interoperability, governance, privacy, and sustainable consensus design.
Bitcoin transaction fees will become more important as the block subsidy declines, but fee formation is hard to study with blockchain data alone because the relevant queueing environment is unobserved. We develop and estimate a structural model of Bitcoin fee choice that treats the mempool as a market for scarce blockspace. We assemble a novel, high-frequency mempool panel, from a self-run Bitcoin node that records transaction arrivals, exits, block inclusion, fee-bumping events, and congestion snapshots. We characterize the fee market as a Vickery-Clarke-Groves mechanism and derive an equation to estimate fees. In the first-stage we estimate a monotone delay technology linking fee-rate priority and network state to expected confirmation delay. We then estimate how fees respond to that delay technology and to transaction characteristics. We find that congestion is the main determinant of delay; that the marginal value of priority is priced in fees, which is increasing in the gradient of confirmation time reduction per movement up in the fee queue; and that transactor choice of RBF, CPFP, and block conditions have economically important effects on fees.
Platform monopolies have turned the contemporary internet into digital feudalism, extracting profit from human connection while enabling surveillance and censorship. Iran’s 2019 near-blackout, which cut connectivity to 5 %, exposed how centralized architectures become authoritarian chokepoints. Yet scholarship remains fragmented: most studies isolate protocols instead of synthesizing how technical design and political economy co-evolve. We compare federated systems such as ReP2P Matrix, Nostr’s peer-to-peer networks, Bluesky’s AT Protocol, blockchain communication hybrids, and Named Data Networking. Our multi-method study of decentralized internet alternatives blends traffic analytics of 4 million Nostr users on 600 relays, performance benchmarks, economic sustainability modeling, and architectural case studies. We ask whether these designs can fulfil the promise of a truly decentralized internet. The evidence is mixed. SendingNetwork scales group messaging linearly, and Waku proves spam-resistant peer-to-peer networks with <300 ms proof generation; however, no single protocol reconciles censorship resistance, usability, and economic sustainability. Nostr delivers uncompromising censorship resistance yet consumes 35 × the resources of centralized systems. Bluesky’s growth leaves 98.9 % of identities non-portable. Community mesh networks invite new hierarchies of technical privilege. Accepting irreducible trade-offs must guide emerging web3 governance. Communities will choose architectures aligned with their values, but meaningful decentralization will remain aspirational until funding models and accessibility gaps are resolved.
Progressive Web Applications (PWAs) have emerged as a transformative paradigm in modern software engineering, combining the reach of the web with the capabilities of native applications. Simulta- neously, decentralized systems—anchored by blockchain technology, distributed ledger frameworks, and peer-to-peer networking protocols—are reshaping trust architectures across industries ranging from finance and healthcare to supply chain and digital identity. Despite the clear synergies between these two technological pillars, the intersection of PWAs and decentralized systems remains relatively underexplored in the academic literature. This survey addresses that gap by systematically reviewing and analyzing the convergence of PWA design principles with decentralized infrastructure paradigms. We examine how service workers, Web App Manifests, push notifications, and IndexedDB offline storage can be effectively integrated with blockchain nodes, smart contracts, IPFS-based content stor- age, and decentralized identity (DID) frameworks to produce resilient, censorship-resistant, and user- centric applications. We survey thirteen seminal works spanning cross-platform application devel- opment, blockchain architecture, decentralized identity management, IoT integration, and distributed application (DApp) design. Our analysis reveals recurring challenges including transaction latency, key management complexity, offline consistency under Byzantine fault conditions, and the tension between decentralization purity and user experience expectations. We further synthesize findings through a structured comparative analysis across six dimensions: focus area, PWA feature utilization, blockchain integration depth, reported performance metrics, and identified limitations. Based on this synthesis, we identify open research directions and propose guidelines for practitioners seeking to build production-grade PWA-based DApp frontends. This survey contributes a consolidated reference for researchers and engineers working at the intersection of web engineering and decentralized computing.
Yuqin Wang, Zhengkang Du, Jiannong Cao, Shan Jiang
The proliferation of web3 has underscored the need for robust and efficient decentralized data infrastructure. However, prominent decentralized storage systems like IPFS suffer from poor data availability and the risk of cold data loss, while incentive-based solutions like Filecoin and Storj employ uniform replication strategies that are often inefficient and costly. These systems fail to distinguish between frequently accessed ("hot") and infrequently accessed ("cold") data, leading to a suboptimal allocation of storage resources. This paper introduces TRep, a novel Temperature-aware Data Replication strategy designed to address these challenges. TRep implements a dynamic replication policy by classifying data based on its access temperature. The system is built on three key innovations: (1) a highly accurate data classification algorithm using double exponential smoothing to analyze access frequency and trends; (2) an intelligent data distribution strategy that selects optimal backup nodes based on storage availability, online stability, and network proximity; and (3) a dynamic backup regulation mechanism, managed by a regulator node, to globally control replica counts for hot and cold data. Our performance evaluation demonstrates that TRep's classification algorithm significantly reduces prediction errors compared to traditional methods. Furthermore, TRep achieves speeds up to four times faster than IPFS for large files while effectively managing storage overhead. TRep thus provides a flexible and performant framework for data replication, enhancing the durability and efficiency of web3 data infrastructure.
Oliver Aleksander Larsen, Rasmus Stenbak Larsen, Mahyar Tourchi Moghaddam
Today's internet concentrates identity, payments, communication, and content hosting under a small number of corporate intermediaries, creating single points of failure, enabling censorship, and extracting economic rent from participants. We present BitSov, an architectural framework for sovereign internet infrastructure that composes existing decentralized technologies (Bitcoin, Lightning Network, decentralized storage, federated messaging, and mesh connectivity) into a unified, eight-layer protocol stack anchored to Bitcoin's base layer. The framework introduces three architectural patterns: (1) payment-gated messaging, where every transmitted message requires cryptographic proof of a Bitcoin payment, deterring spam through economic incentives rather than moderation; (2) timechain-locked contracts, which anchor subscriptions and licenses to Bitcoin block height (the timechain) rather than calendar dates; and (3) a self-sustaining economic flywheel that converts service revenue into infrastructure growth. A dual settlement model supports both on-chain transactions for permanence and auditability and Lightning micropayments for high-frequency messaging. As a position paper, we analyze the quality attributes, discuss open challenges, and propose a research agenda for empirical validation.
Alternative blockchains have emerged as innovative solutions to overcome the limitations of early technologies like Bitcoin and Ethereum, while expanding the potential applications of decentralized networks. These blockchains introduce distinctive features, consensus mechanisms, and scalability solutions tailored to specific use cases, enhancing both versatility and efficiency. Notable examples include Binance Smart Chain (BSC), Cardano, Solana, Polkadot, and Avalanche. Binance Smart Chain (BSC) leverages a dual-chain architecture, enabling users to develop decentralized applications and digital assets on one chain while benefiting from fast transactions on the other. Cardano, built through a rigorous peer-reviewed process, prioritizes scalability, interoperability, and sustainability, utilizing the Ouroboros proof-of-stake consensus mechanism. Solana emphasizes high throughput and low latency, employing a unique proof-of-history consensus to achieve transaction speeds far surpassing those of traditional blockchains. Polkadot introduces a multi-chain framework that allows independent blockchains to communicate and share value without relying on centralized intermediaries. Its “parachain” system fosters interoperability and enhances scalability across networks. Meanwhile, Avalanche offers a consensus protocol designed for low-latency finality and high throughput, enabling the creation of customizable blockchain networks tailored to specific applications, all the while preserving robust security guarantees.