Blockchain Papers

Xiaohong Chen, Grigore Roşu

No abstract is available for this record.

Ziwei Wang, Cong Wu, Paolo Tasca

Sharding has emerged as a critical solution to address the scalability challenges faced by blockchain networks, enabling them to achieve higher transaction throughput, reduced latency, and optimized resource usage. This paper investigates the advancements, methodologies, and adoption potential of sharding in the context of Hedera, a distributed ledger technology known for its unique Gossip about Gossip protocol and asynchronous Byzantine Fault Tolerance (ABFT). We explore various academic and industrial sharding techniques, emphasizing their benefits and trade-offs. Building on these insights, we propose a hybrid sharding solution for Hedera that partitions the network into local and global committees, facilitating efficient cross-shard transactions and ensuring robust security through dynamic reconfiguration. Our analysis highlights significant reductions in storage and communication overhead, improved scalability, and enhanced fault tolerance, demonstrating the feasibility and advantages of integrating sharding into Hedera's architecture.

Oleksandr Berezovskyi, Bohdan Melnyk, Grygoriy Zholtkevych, Nataliya Melnyk · 6 authors

This paper studies the aspects of Distributed Ledger Technology (DLT) related to deciding how to order incoming ledger data records under the requirement to provide transparency and security in public information systems, particularly in the context of e-government. The study addresses the challenges of synchronizing ledger replicas across distributed systems, ensuring consistency and reliability in data storage and retrieval. The research highlights the importance of maintaining a unified ledger state, which is crucial for decisionmaking processes in the public and social sectors. The proposed solution combines Lamport's clock algorithm with wave algorithms to overcome the limitations of traditional timestamping methods, such as the duplication of timestamps for concurrent events. This approach ensures that each event in the distributed ledger is uniquely identified, thereby enhancing the system's robustness and efficiency.

Namrata Marium Chacko, V G Narendra, Mamatha Balachandra, T Manoj

Blockchain technology has seen a rapid pace of development and expanded application domains swiftly due to the rising demand for decentralized trust, transparency, and integrity. The consensus algorithm plays a critical role in ensuring trust, immutability and governance of the decentralized network. However, traditional consensus face challenges such as high energy consumption, low scalability, security, and fault tolerance. Researchers have been investigating Lightweight Consensus to overcome these challenges. Lightweight Consensus is a mechanism that enables a more efficient and scalable blockchain system while ensuring security and immutability. This work uses the Systematic Literature Review method to comprehend Lightweight Consensus. 127 studies were grouped based on application specific network, and an in-depth analysis was done on the characteristics of the consensus. A novel taxonomy of Lightweight Consensus based on the agreement method and round propagation is proposed. Various parameters that needed consideration for a Lightweight Consensus are also analyzed. Finally, the study makes recommendations for future research on Lightweight Consensus in blockchain, emphasizing the importance of more empirical investigations and real-world implementations. This study offers a comprehensive overview of the current research landscape on lightweight consensus in blockchain, shedding light on its potential impact on the evolution of blockchain technology. It also serves as a valuable guide for researchers, helping them identify the most suitable consensus features for specific application domains with unique requirements.

Anshjyot Singh Wadhwa

Traditional blockchain protocols incentivize constant participation through resource-intensive mechanisms such as Proof-of-Work (PoW) or Proof-of-Stake (PoS). However, this model leads to excessive energy consumption and network redundancy. This paper proposes a novel consensus auxiliary protocol called Proof-of-Inactivity (PoI), wherein nodes earn trust by deliberately abstaining from consensus activities for defined, randomized periods. Inactivity is cryptographically proven via time-locked commitments and publicly verifiable absence proofs. This paradigm aims to reduce redundant communication, lower energy usage, and support lightweight node participation without compromising network integrity. The protocol is introduced alongside a security assessment, performance analysis, and possible energy savings based on simulated scenarios, including conversations about DIDs, zero-knowledge mechanism, hybrid consensus, and adaptability.

Zhihua Shen, Qiang Qu, Xuebo Chen

In recent years, blockchain consensus mechanisms have evolved significantly from the original proof-of-work design, transitioning towards more efficient and scalable alternatives. This paper presents a comprehensive review and analysis framework for blockchain consensus mechanisms based on a systematic examination of 200+ publications. We categorize consensus mechanisms into four performance-oriented groups: high throughput, strong security, low energy, and flexible scaling, each addressing specific trade-offs in the blockchain trilemma of decentralization, security, and scalability. Through quantitative metrics including transactions per second, energy consumption, fault tolerance, and communication complexity, we evaluate mainstream mechanisms. Our findings reveal that no single consensus mechanism optimally satisfies all performance requirements, with each design involving explicit trade-offs. This paper provides researchers and practitioners with a structured framework for understanding these trade-offs and selecting appropriate consensus mechanisms for specific application contexts. Finally, we discussed future development trends, as well as regulatory and ethical considerations.

Matter, Jan, Muoi Tran

The InterPlanetary File System (IPFS) has been successfully established as the de facto standard for decentralized data storage in the emerging Web3. Despite its decentralized nature, IPFS nodes, as well as IPFS content providers, have converged to centralization in large public clouds. Centralization introduces BGP routing-based attacks, such as passive interception and BGP hijacking, as potential threats. Although this attack vector has been investigated for many other Web3 protocols, such as Bitcoin and Ethereum, to the best of our knowledge, it has not been analyzed for the IPFS network. In our work, we bridge this gap and demonstrate that BGP routing attacks can be effectively leveraged to censor content in IPFS. For the analysis, we collected 3,000 content blocks called CIDs and conducted a simulation of BGP hijacking and passive interception against them. We find that a single malicious AS can censor 75% of the IPFS content for more than 57% of all requester nodes. Furthermore, we show that even with a small set of only 62 hijacked prefixes, 70% of the full attack effectiveness can already be reached. We further propose and validate countermeasures based on global collaborative content replication among all nodes in the IPFS network, together with additional robust backup content provider nodes that are well-hardened against BGP hijacking. We hope this work raises awareness about the threat BGP routing-based attacks pose to IPFS and triggers further efforts to harden the live IPFS network against them.

Stephen Kirkman, Richard E. Newman, Christopher Garcia

The Ethereum Trilemma states that security, scalability, and decentralization cannot all be achieved at the same time in a blockchain. We call this the ‘Ethereum’ Trilemma because there are solutions to generic blockchain scalability. Due to the added computation, Ethereum has certain challenges that so far cannot be solved without going to Layer 2 or completely changing the base chain. Layer 2 scaling techniques are add-ons to Layer 1 (the base chain). These scaling techniques, may, in some cases reduce the security of the blockchain - but it depends on the definition of security one uses. We examine the implications of Layer 2 scaling (particularly optimistic rollups since they are most popular) and note that decentralized computation and smart contract security have been relegated to a back seat at best or tossed out completely at worst - validation appears to be left behind. This is a gap in rollups that neither Optimistic Rollups nor ZK-Rollups fill. We propose to fill that gap with what we call an $\mathrm{n} \%$-Validations Rollup that bring some validation back - not fully decentralized, but not completely centralized either; the best of both worlds. In our vision, the user needs more options to specify their desired level of decentralized validation. Currently, if you use a rollup, you have potentially no Layer 1 validation. On the other extreme, too much validation is the scaling roadblock. This position paper suggests avenues for research of these issues. This is a transitional period for Ethereum and Layer 2 appears to have become the wild west.

Tucci, Lorenzo

From the earliest markets to today’s globally interconnected economies, exchanging money has been a defining feature of civilization. While historically centralized institutions have been in charge of securing and finalizing transactions, the advent of Bitcoin has marked the birth of decentralized finance. In this new paradigm, trust is no longer placed in a specific government, institution or corporation, but instead on mathematical proofs, protocol design and cryptographic assumptions. In an ever increasingly multipolar world - where financial censorship and transaction surveillance are becoming common coercion tools - the appeal of uncensorable money continues to grow. While a variety of decentralized financial systems exist, their interoperability remains a critical challenge. In this thesis, we study existing solutions and propose new methods for cross-system assets exchange. We first examine how to realize secure peer-to-peer (P2P) asset exchange protocols between two users. Such a task can be accomplished by a class of blockchain protocols known as atomic swaps, and we highlight the limitations of solutions that either require the underlying blockchain to support scripting or rely on a computionally intensive cryptographic primitive known as timelock puzzles. In order to improve on the current state of the art, we identify and propose a natural and minimal blockchain functionality called commit transactions, which we show to be sufficient to realize generic atomic swaps protocols. We next investigate how multiple users can establish a decentralized exchange service. Building on top of the traditional liquidity pool setting, we describe a system that extends to a cross-chain environment. We provide a costruction that, under an assumed setup mechanism, realizes an universal exchange protocol. Finally, we explore how such solutions can be realized in the most challenging setting of private and anonymous systems. Specifically, we focus into achieving compability with the most commonly traded private cryptocurrency, Monero. We propose a modifications to adapt Monero’s transaction scheme, ring confidential transactions (RingCT), to the newly proposed atomic swap protocol.

Shuo Xu

This paper proposes a framework that integrates zero-knowledge proofs (ZKPs) and verifiable credentials (VCs) to achieve the synergistic optimization of transaction privacy and trusted identity authentication. First, a pseudonymous transaction protocol based on zk-SNARKs (zero-knowledge succinct non-interactive arguments of knowledge) is designed. The R1CS constraint system is used to construct a circuit that hides the transaction amount and address, resulting in a proof that takes up only 1.5 KB. Second, the W3C standard VC is introduced to enable off-chain identity attribute authentication. Users generate a “credential validity proof” using ZKPs and upload the proof along with the transaction to the chain. Finally, smart contracts verify the dual proofs, using Merkle tree aggregation to reduce verification overhead. An innovative “attribute-bound anonymous transaction” model is proposed to dynamically decouple transaction and identity attribute verification. Deployment on the Ethereum testnet demonstrates that this scheme reduces transaction correlation to approximately 0.3 %. Groth16 achieves a throughput of 142 transactions per second (TPS) in 798 ms at a scale of 200,000 gates.

Taehoon Yoo, Kiseok Kim, Hwangnam Kim, Hwangnam Kim

No abstract is available for this record.

Vincenzo Arceri, Saverio Mattia Merenda, Luca Negrini, Luca Olivieri · 5 authors

Ethereum enables the creation and execution of decentralized applications through smart contracts, that are compiled to Ethereum Virtual Machine (EVM) bytecode. Once deployed in the blockchain, the bytecode is immutable; hence, ensuring that smart contracts are bug-free before their deployment is of utmost importance. A crucial preliminary step for any effective static analysis of EVM bytecode is the extraction of the control-flow graph (CFG): this presents significant challenges due to potentially statically unknown jump destinations. In this paper we present a novel approach, based on Abstract Interpretation, aiming to build a sound CFG from EVM bytecode smart contracts. Our analysis, which is implemented in our static analyzer EVMLiSA, is based on a parametric abstract domain that approximates concrete execution stacks at each program point as an l -sized set of abstract stacks of maximal height h ; the results of the analysis are then used to resolve the jump destinations at jump nodes. Furthermore, EVMLiSA includes a checker for reentrancy detection, working on the constructed CFG. Our experiments show that, by fine-tuning the analysis parameters, EVMLiSA is able to build sound CFGs for all real-world smart contracts in the considered benchmark suite. Moreover, EVMLiSA successfully detects all reentrancy vulnerabilities in EVM bytecode smart contracts, while producing a small number of false positives.

Yunus Kareem, Djamel Djenouri, Essam Ghadafi

Blockchain is expected to play a key role in securing next generation communication systems, i.e., B5G and 6G, which will be highly decentralised, with high integration of edge computing, device-to-device (D2D) communications, and notably IoT networks. This paper addresses a fundamental bottleneck of blockchain; the simulation of consensus algorithms. State-of-the-art blockchain consensus algorithm simulators are built on general data that do not consider resource-constrained devices. These simulators have limitations in performance measurement (energy, latency, and throughput) and testing of security attacks, including DoS, Sybil, and 34% or 51% attacks). This paper introduces a blockchain Internet of Things consensus algorithm (BICA) simulator, which offers a framework for testing consensus algorithms with adaptable IoT data in various attack scenarios. It evaluates metrics such as latency, throughput, and attack resilience, providing insights into their capabilities under diverse network conditions. A case study involving Proof of Stake (PoS), Delegated Proof of Stake (DPoS), Proof of Elapse Time (PoET), Proof of Authority (PoA) and Practical Byzantine Fault Tolerance (PBFT) showed PBFT’s superior performance and security against vulnerabilities such as Sybil, DoS, and 34-51% attacks. BICA’s block-creation speed surpasses that of the existing simulators.

Andrea Esposito, Francesco Rossi, Marco Bernardo, Francesco Fabris · 5 authors

Algorand is a scalable and secure permissionless blockchain that achieves proof-of-stake consensus via cryptographic self-sortition and binary Byzantine agreement. In this paper we present a process algebraic model of the Algorand consensus protocol with the aim of enabling formal verification. Our model captures the behavior of participants in terms of the structured alternation of consensus steps toward a committee-based agreement. We validate the correctness of the protocol in the absence of adversaries and then extend our model to assess the influence of coordinated malicious nodes that can force the commit of an empty block instead of the proposed one. The adversarial scenario is analyzed through an equivalence-checking-based noninterference framework that we have implemented in the CADP verification toolkit. In addition to highlighting both the robustness and the limitations of the Algorand protocol under adversarial assumptions, this work illustrates the added value of using formal methods for the analysis of consensus algorithms within blockchains.

SATHISHKUMAR RANGANATHAN, Muralindran Mariappan, M. Karthigayan

Consensus mechanisms are essential in swarm robotics to maintain uniformity of decisions and states across distributed agents. Earlier methods often relied on approaches such as majority voting, averaging techniques, or leader election. In recent years, blockchain-based algorithms including Proof of Work (PoW), Proof of Stake (PoS), Practical Byzantine Fault Tolerance (PBFT), and Raft have been adopted for this purpose. While these methods provide certain advantages, their application to swarm robotics is restricted by issues such as limited computational power, energy constraints, scalability challenges caused by message complexity and latency, and weak protection against Byzantine agents. This study introduces a consensus approach specifically designed to address these gaps and to improve collaborative decision-making in swarm environments. The work outlines the motivation for the proposed solution, describes the simulation-based experimental design, and presents a detailed analysis of the observed results.

Yassine Maadallah, Younès El Bouzekri El Idrissi, Youssef Baddi

Blockchain technology offers a promising foundation for trustworthy, auditable communication in Internet of Things (IoT) networks. In such settings, the consensus protocol is the primary determinant of feasibility because devices operate under tight constraints in energy, computation, latency, and bandwidth. This paper delivers a structured comparative review of Proof of Work (PoW) and Proof of Stake (PoS) in the context of IoT. We first articulate their operating principles, security assumptions, and threat models, then evaluate trade-offs across throughput, latency, scalability, energy consumption, hardware requirements, and attack resistance. While PoW provides strong probabilistic finality and robust security under open membership, its high energy cost and mining difficulty make it poorly aligned with low-power sensor/actuator nodes. PoS and PoS-inspired variants reduce resource use and enable faster confirmation, but require careful design to mitigate concentration risks, long-range and nothing-at-stake attacks, and to preserve decentralization. Beyond these canonical schemes, we review emerging alternatives tailored to IoT, including lightweight PoW, committee-based BFT hybrids, and DAG-based ledgers that decouple consensus from transaction validation. We synthesize implementation considerations, including identity and stake management, clock synchronization, network churn, and intermittent connectivity, and outline selection guidelines for common IoT deployment patterns (edge-centric, gateway-assisted, and intermittently connected swarms). Our analysis indicates that PoS and related frameworks are generally better suited for IoT, particularly when combined with hierarchical or hybrid designs. The review concludes with open research directions and a pragmatic checklist for researchers and practitioners evaluating consensus for constrained IoT systems.

Michele Ciampi, Luisa Siniscalchi

No abstract is available for this record.

Rachid Guedjali, Jean‐Philippe Georges, Sylvain Kubler

This paper presents a framework for analyzing and modeling validator behavior in dynamic consensus protocols. A discrete state-based model is proposed in order to represent four key validator states: majority, non-faulty minority, faulty minority, and non-validator, enabling systematic behavioral analysis through three complementary metrics: Jensen-Shannon Divergence (JSD) for entropy-based behavioral differences, the Bhattacharyya Coefficient for distribution similarity, and Wasserstein distance for state transition costs. To identify coherent validator groups and detect outliers, an HDBSCAN (Hierarchical Density-Based Spatial Clustering of Applications with Noise) clustering is used since it is well-suited for detecting clusters in data with varying densities. Using JSD-based similarity measures in HDBSCAN, transient convergence patterns and stable behavioral clusters are uncovered, even in decentralized networks with diverse fault conditions. Simulation results on a 50-node network demonstrate the framework’s effectiveness, providing insights into system dynamics and offering tools for validator selection, fault detection, and stability monitoring in distributed ledger systems. This approach is particularly relevant, as consensus protocols evolve beyond traditional PBFT (Practical Byzantine Fault Tolerance) implementations, combining theoretical metrics with clustering techniques to enhance consensus robustness.

Meihua Xiao, Y. P. Xu, Yongtuo Zhang, Ke Yang · 6 authors

Smart contracts, as a critical application of blockchain technology, significantly enhance its programmability and scalability, offering broad application prospects. However, frequent security incidents have resulted in substantial economic losses and diminished user trust, making security issues a key challenge for further development. Since smart contracts cannot be modified after deployment, flaws in their design or implementation may lead to severe consequences. Therefore, rigorous pre-deployment verification of their correctness is particularly crucial. This paper explores the symmetry in control flows and state transitions of Solidity smart contracts and leverages this inherent structural symmetry to develop a normalized state transition model based on a finite state machine. The FSM model is subsequently formalized into a Promela model with the Spin model checker. By integrating manually defined Linear Temporal Logic formulas with those generated by Smart Pulse, the Promela model is formally verified in Spin to ensure the correctness and security of smart contracts. This approach establishes a systematic verification framework, providing effective support to enhance the reliability and security of smart contracts.

Bingsheng Zhang, Wuyunsiqin Wuyunsiqin, Xun Zhang, Markulf Kohlweiss · 5 authors

In blockchain systems, Merkle trees represent a fundamental cryptographic structure for verifying the validity of public keys in digital signatures. However, the verification process presents significant computational challenges, particularly when dealing with large-scale public key participation in signing operations. This paper focuses on addressing the efficiency bottlenecks in public key validity verification within Merkle tree commitments, with particular emphasis on their application in trustless cross-chain bridge protocols. While existing cross-chain solutions predominantly rely on zero-knowledge proofs for blockchain state validation, the inherent computational cost of proof generation remains prohibitive.We present a novel batch opening scheme for Merkle tree commitments that synergistically integrates Merkle tree construction from permutation arguments to verify the membership of extensive leaf sets. Our approach demonstrates remarkable proof generation efficiency advantages, particularly maintaining consistent performance regardless of the number of opened leaves, given a fixed tree depth. Our methods significantly reduce the computational overhead associated with public key validity verification. Meanwhile, it is fully applicable to the existing classical Merkle tree structure without any modifications and has universality.To demonstrate the practicality and efficiency of our scheme, We implemented the Merkle tree opening circuit for three hash functions (Poseidon, Rescue and Keccak) based on our scheme. Our evaluation shows that the batch opening scheme achieves better performance: proof generation time begins to shorten from an opening ratio of 0.25, achieving a 3.5 to 7.1× improvement at a ratio of 0.75 (with tree depth = 9). Similar improvements are also reflected in the proof size and verification time. Moreover, as tree depth increases, our method’s performance advantages become more pronounced.

Siamak Abdi, Giuseppe Di Fatta, Atta Badii, Giancarlo Fortino

Blockchain is a distributed ledger technology that has applications in many domains such as cryptocurrency, smart contracts, supply chain management, and many others. Distributed consensus is a fundamental component of blockchain systems that enables secure, precise, and tamper-proof verification of data without relying on central authorities. Existing consensus protocols, nevertheless, suffer from drawbacks, some of which are related to scalability, resource consumption, and fault tolerance. We introduce Blockchain Epidemic Consensus Protocol (BECP), a novel fully decentralised consensus protocol for blockchain networks at a large scale. BECP follows epidemic communication principles, without fixed roles like validators or leaders, and achieves probabilistic convergence, efficient message dissemination, and tolerance to message delays. We provide an extensive experimental comparison of BECP against classic protocols like PAXOS, RAFT, and PBFT, and newer epidemic-based protocols like Avalanche and Snowman. The findings indicate that BECP provides desirable gains in throughput, consensus latency, and substantial message-passing efficiency compared to existing epidemic-based approaches, validating its usability as an effective and scalable approach for next-generation blockchain systems.

Venkata Raghava Kurada, Shirdeesh Budharam, Pallav Kumar Baruah

Data marketplace are rapidly gaining traction as critical components of the modern data economy. However, traditional centralized marketplaces suffer from inherent challenges such as data leakage, lack of user control and single points of failure. To address these limitations, we propose Versatile Peer Network (VePran) – a decentralized data market place built on the Web3 suite of technologies. VePraN is designed to be modular, scalable and aligned with open standards, ensuring broad interoperability and future extensibility. Leveraging the InterPlanetary File System for persistent storage and blockchain for identity and ownership management, the platform offers a robust infrastructure that enhances data security and provenance. Unlike existing buyer centric solutions, VePraN adopts a seller oriented approach, empowering data owners with greater autonomy, fair exchange and control over their data assets. In addition to enabling secure data exchange, the platform facilitates the trading of machine learning models, expanding its utility in AI driven ecosystems. Verification mechanisms such as Merkle roots and Non- Fungible Tokens are employed to ensure data integrity and authenticity. This paper presents the architecture and implementation of VePraN as a foundational step toward a more equitable and resilient data exchange system.

Deepsingh Chhabda, Mehaerkaur Chhabda

Blockchain consensus algorithms face trade-offs between performance, security, decentralization, and energy efficiency. Proof-of-Work (PoW) ensures strong security but is energy-intensive. Proof-of-Stake (PoS) is efficient but may risk centralization. Byzantine Fault Tolerance (BFT) offers low latency but lacks scalability. This paper proposes an Adaptive Hybrid Consensus (AHC) algorithm that dynamically integrates PoW, PoS, and BFT elements. The AHC mechanism is designed for general-purpose blockchain environments and can adapt to real-time network conditions. AHC is a promising solution for next-generation blockchain systems as it has the potential to significantly improve latency, throughput, and energy consumption [13][14].

Ran Wang, Fuqiang Ma, S.H. Tang, Zhiyuan Su · 5 authors

ABSTRACT Establishing common knowledge about environmental conditions, task objectives, and coordination rules is crucial for improving the collaborative efficiency of swarm robots. In complex scenarios, relying on a centralized facility to maintain this knowledge is impractical, necessitating a decentralized approach. Blockchain technology offers a promising solution for decentralization and can tolerate some degree of malicious or malfunctioning entities. However, widely used blockchain approaches, such as those employed in Ethereum and relying on proof‐of‐work (PoW) or proof‐of‐authority (PoA), demand significant computational resources, rendering them impractical for swarm robotics applications. This paper introduces PTEE‐BFT, a novel parallel Byzantine fault tolerance protocol leveraging the trusted platform module (TPM). PTEE‐BFT employs a Unique Sequential Identifier Generator (USIG) to ensure the monotonicity, uniqueness, and order of messages, thereby reducing the number of communication phases and replicas required. This significantly enhances the efficiency and fault tolerance of the consensus process. Additionally, PTEE‐BFT implements parallel processing strategies to substantially increase blockchain system throughput. Furthermore, we develop an algorithm that enables the robot swarm to recognize attacks from a specific type of malicious robot known as Byzantine robots. Our experimental analysis and performance evaluation demonstrate that PTEE‐BFT achieves an optimal balance among performance, scalability, and fault tolerance, outperforming practical Byzantine fault tolerance (PBFT). Results from physical robots show that our approach significantly reduces computing overhead and accelerates consensus formation compared to baseline solutions. This represents a significant advancement in blockchain consensus mechanisms for swarm robotics.