This paper extends BlockSim by introducing energy-consumption and carbon-footprint metrics that are tightly integrated with its event-driven execution model, enabling sustainability-aware evaluation alongside conventional performance metrics. The proposed extension instruments core simulation events to estimate computational and communication energy at both node and network levels, then converts electricity demand to CO 2 emissions using an emission-factor formulation that can be configured to represent different grid carbon intensities. Using the extended simulator, controlled experiments are conducted on representative PoW and PoS consensus scenarios under varying miner populations and workloads. The framework reports aggregate energy and CO 2 , as well as normalized indicators per block and per transaction, supporting reproducible “what-if” analysis without external post-processing and enabling direct comparison of protocol configurations as networks scale. The framework additionally distinguishes economically driven Proof-of-Work (PoW) energy consumption, in which the expected mining reward and cryptocurrency price are explicit inputs, from validator-count-driven Proof-of-Stake (PoS) energy consumption; it varies the carbon emission factor across grid scenarios; and it is positioned as a scenario-based evaluation tool for preliminary what-if analysis rather than a precise real-world energy estimator.
Layer 2 scaling solutions—including payment-channel-based Lightning Networksand rollup-based off-chain execution environments—are commonly understood aslinear scaling projects for blockchain transaction throughput. This paper proposesan alternative structural interpretation: the emergence of Layer 2 is not a continuous increase in system capacity, but a percolation phase transition that occurswhen the density of off-chain channels or cross-rollup connections crosses a critical threshold. During this phase transition, the system shifts from a fragmentedlocally connected state to a globally routable giant connected state. The paperanalyzes the Lightning Network and the rollup ecosystem as comparative cases.Empirical studies of the Lightning Network show that its scale-free topology forcescritical hub nodes to bear a disproportionate connection load, thereby binding thenetwork’s global connectivity to the survival of a few high-centrality nodes. Therollup ecosystem faces the structural predicament of liquidity fragmentation, and itsevolution toward cross-rollup interoperability likewise exhibits a phase-transitionlogic from quantitative change to qualitative change in network effects. Based onthe above analysis, this paper distills three design principles for Layer 2 scalability:facilitating the institutionalization of cross-domain connections, avoiding overlyhomogenized cognitive convergence, and implementing differentiated verificationrouting among tasks with different security requirements.
This preprint is available in two versions: French (main_fr.pdf / main_fr.tex) and English (main_en.pdf / main_en.tex). The English abstract follows. For over one hundred and fifty years, all railway signalling architectures have rested on a single assumption: safety authority resides in the ground infrastructure. The network authorises; the train obeys. We question its necessity. The physical safety condition is a local property of the train and its environment, verifiable without external authorisation. We propose an architecture — AEGIS (Autonomous Embedded Ground-Independent Signalling) — in which neither primary safety nor installation coordination depends on a centralised ground authority: the ground provides certified data, the train reasons, and installation coordination is handled by a topologically partitioned distributed ledger. We examine the architectural properties arising from this inversion, the emergent properties of the resulting system, and the open questions this new paradigm generates.
Lyudmila Kovalchuk, Mariia Rodinko, Roman Oliynykov, Volodymyr Artemchuk
This paper studies the probability of a double-spend attack in an Ouroboros-like Proof-of-Stake (PoS) setting when confirmation decisions must be made for a finite number of blocks. Existing security analyses of Ouroboros-family protocols are mainly asymptotic and therefore do not directly provide the attack probability for a fixed confirmation depth. We consider an analytically tractable model that allows empty slots and multiple slot leaders, and assumes fixed stake distribution within an epoch, one-block growth of the public longest chain in any slot containing at least one honest leader, and next-slot block visibility. These assumptions hold when the time slot length is much greater than the network delay, and are applicable to practical deployment scenarios such as Cardano. Under these assumptions, for the first time, an exact closed-form solution for the success probability of a double-spend attack considering a realistic model with multiple leaders and empty time slots. Numerical examples illustrate how the required confirmation depth depends on the adversarial stake ratio and the active slot coefficient. The results apply to the stated analytical model and do not yet cover delayed fork resolution or the full protocol-level fork-choice and finality mechanisms of Ouroboros Praos.
O presente artigo investiga como o tamanho do bloco afeta a propagação em redes blockchain, recorrendo à modelagem estocástica para quantificar os trade-offs entre throughput, segurança e descentralização. Estudos teóricos e empíricos indicam que blocos maiores elevam o tempo médio de propagação e a variância desse tempo, aumentando a probabilidade de forks e de blocos órfãos em mecanismos de consenso baseados em Prova de Trabalho (PoW) e variantes de Nakamoto. Modelos analíticos e de simulação demonstram que a relação entre o intervalo médio de geração de blocos e o atraso médio de propagação pode ser tratada por meio de sistemas de filas ou de processos de Poisson, nos quais a taxa de forks cresce quando o produto “taxa de blocos × atraso de propagação” se aproxima de um limiar crítico associado a um regime congestionado. Resultados de trabalhos de otimização de tamanho de bloco em PoW sugerem a existência de um tamanho “ótimo” que maximiza a eficiência econômica da rede – isto é, transações por segundo ponderadas pelo risco de órfãos –, e que esse ótimo depende fortemente da largura de banda média da rede e do grau de heterogeneidade entre nós. Evidências empíricas da rede Bitcoin mostram ainda que melhorias de protocolo, tais como Compact Blocks e redes de relay dedicadas, reduzem significativamente o impacto negativo de blocos maiores sobre a propagação, conquanto não eliminem o viés estrutural em favor de nós com melhor conectividade. Conclui-se que a modelagem estocástica do impacto do tamanho de bloco é fundamental para parametrizar blockchains de modo a manter a rede em regime funcional, minimizando taxa de forks e força centralizadora, ao mesmo tempo em que se atende à demanda por maior capacidade transacional na Web3.Blockchain
Payment channel networks enable scalable off-chain payments, but their practical deployment remains constrained by a persistent tension among routing efficiency, liquidity visibility, transaction privacy, and settlement security. Existing multipath routing mechanisms can improve payment success under fragmented liquidity, yet they often expose sensitive balance information, leak structural features of payment routes, and enlarge the attack surface for probing, channel exhaustion, and selective forwarding. This paper presents a novel framework, Adaptive Multipath Proofs (AMPs), for privacy protection and security in payment channel networks. The core idea is to bind multipath routing decisions with lightweight zero-knowledge verifiability, allowing intermediate nodes to validate path feasibility, fragment consistency, and settlement constraints without learning exact channel balances, the complete payment amount, or the global route structure. AMP integrates three mechanisms: a hidden-liquidity feasibility proof that supports privacy-preserving route selection, an adaptive payment-splitting strategy that dynamically determines fragment allocation according to network congestion and balance uncertainty, and a proof-coupled settlement guard that enforces atomicity and timeout consistency across all payment fragments. Together, these mechanisms reduce information leakage while preserving robust payment execution under dynamic network conditions. Experimental evaluation on real Lightning Network topologies and synthetic stress scenarios demonstrates that AMP significantly lowers balance disclosure and endpoint inference risk, improves payment completion under skewed liquidity distributions, and introduces only moderate computational and communication overhead. The results indicate that adaptive proof-carrying multipath routing offers a practical and effective direction for building secure, privacy-preserving, and high-success payment channel networks.
Blockchain technology has emerged as a core enabler of decentralized digital infrastructure by offering inherent features such as immutability, distributed trust, and transparency. These characteristics position blockchain as a promising foundation for building sustainable and accountable digital ecosystems. However, despite its growing adoption across domains such as governance, finance, supply chain management, and public services, blockchain systems continue to face critical challenges. Security vulnerabilities, scalability constraints, energy consumption, and transparency—privacy trade-offs remain major barriers to their long-term reliability and sustainability. This study presents a structured analysis of security and transparency challenges in blockchain-based decentralized systems, with specific emphasis on their role in sustainable digital infrastructure. Key architectural components, including consensus mechanisms, decentralization models, and immutable ledger design, are examined to identify structural weaknesses and performance bottlenecks. The primary contribution of this work is the introduction of a unified layered challenge taxonomy that categorizes threats across protocol, network, and application layers, supported by a dataset-driven comparative evaluation of representative blockchain platforms. The findings demonstrate that sustainable blockchain deployment requires carefully balanced design strategies that integrate efficiency, security, and transparency rather than optimizing any single dimension in isolation. This work provides practical insights and reference points for future research aimed at developing secure, scalable, and sustainability-oriented decentralized systems.
Our suggestion is a hybrid reputation-based routing protocol in the context of decentralized routing. networks which partitions trust measurements to on-chain immutable logs and off-chain dynamic computations to attain security and scalability. The protocol incorporates a layer of sharded blockchain to store critical. trust data and local reputation model to do real-time updates, enabling routing choices that cannot be tampered with. performance. The trust ledger which operated on-chain kept the records of the impartiality of. Historical performance and node identities, whereas the off-chain reputation engine uses graph neural network to calculate dynamic. real-time scores like packet delivery rate to be trusted. and latency. Additionally, it uses rollup-based batches of synchronization off-chain. optimistic updates to zero-knowledge proofs, making on-chain efficient. checking with minimum overhead. The suggested approach replaces conventional network discovery and forwarding modules using trust-based adjacency lists and trust-based pathing, and thus enhancing routing consistency over adversarial settings. Moreover, the structure integrates Hyperledger Fabric with. Graph Attention Network-based high-throughput sharded ledger operations. to update reputation in a privacy-preserving manner, proving to be linear. network size scalability. The experimental findings indicate that the system supports 10,000 transactions per shard and produces. Under 100 ms per ZK-Rollup proof, which is appropriate to large-scale IoT. and DeFi deployments. This publication fills the gap between pure on-chain. and off-chain reputation systems, which provides a viable solution to scalable and secure decentralized routing.
Chonghe Zhao, Deen Ma, Xicheng Zhang, Taotao Wang · 5 authors
Ethereum is a leading blockchain system whose security and performance depend critically on efficient transaction propagation. Currently, to curb bandwidth, Ethereum employs a hybrid protocol wherein nodes eager-push full transactions to a random peer subset and announce hashes to the remainder for on-demand lazy-pull. Yet, our MainNet measurements reveal that this strategy suffers from “blind” forwarding—indiscriminately transmitting full transactions without evaluating receiver acceptance. This causes peers to receive multiple redundant copies of non-viable transactions that are ultimately discarded by local pools. Also, randomized peer selection results in substantial redundant transmission, excessive hops, and a high lazy-pull rate (the proportion of transactions acquired via the slower request-response mechanism). These two inefficiencies collectively prolong propagation latency and limit further bandwidth savings. To address these limitations, we propose BELLTP, aBandwidth-Efficient andLow-LatencyTransactionPropagation protocol that incorporates two key awareness modules.Transaction Awarenessclassifies transactions into “urgent” and “leisure” using a lightweight predictor trained on Mainnet data to forecast receiver acceptance. Based on this, leisure transactions (with low predicted acceptance) are propagated via full lazy-pull to ensure that each node receives the full payload once, while urgent transactions utilize strategically targeted eager-push guided by node awareness to rectify random selection inefficiencies.Node Awarenessidentifies hub and common nodes for urgent transaction propagation by combining a theoretical network model, enabling hub nodes to eagerly push to all peers (shortening hop count while maintaining low redundant transmission) and common nodes to leverage a peer need score to eagerly push only to high-need peers (lowering lazy-pull rate). Extensive experiments on Ethereum MainNet and in a controlled local testbed demonstrate that BELLTP significantly outperforms the current protocol in both bandwidth consumption and propagation latency.
Ethereum 2.0 (ETH2) marks a pivotal shift in blockchain technology, transitioning from a Proof-of-Work (PoW) to a Proof-of-Stake (PoS) consensus mechanism, with Gasper at its core. While this evolution promises enhanced scalability and energy efficiency, the performance of its block proposal stage is highly sensitive to network latency and system parameters, such as slot length. This sensitivity introduces a critical trade-off between throughput and security, measured by the probability of blockchain forking. This paper reveals that network latency is not just a passive risk but an exploitable attack surface. We introduce the "adaptive latency-driven equivocation attack", a novel adversarial strategy where an attacker deliberately creates forks while mimicking the behavior of a high-latency node, thus achieving plausible deniability. To formally analyze and quantify the impact of this threat, we develop a comprehensive theoretical model by using Markov chains to analyze the fork probability and throughput of the Gasper's block proposal mechanism under both honest and adversarial conditions. Through extensive simulations, we validate the accuracy of our model in both normal and bursty traffic conditions. Our findings provide a systematic methodology for optimizing system parameters to achieve a robust balance between performance and security, offering a foundational guide for configuring ETH2 networks against sophisticated, latency-based threats.
O presente artigo investiga a otimização do throughput em redes blockchain baseadas em mecanismos de consenso Proof-of-Stake (PoS) a partir de um estudo comparativo de latência entre diferentes arquiteturas, parâmetros de configuração e arranjos de infraestrutura de rede. Partindo do desafio clássico da engenharia de sistemas distribuídos de conciliar escalabilidade, segurança e descentralização – conhecido popularmente como trilema do blockchain –, analisa-se como decisões de projeto, dentre as quais se incluem o desenho do protocolo de consenso, a duração dos intervalos (slots), o tamanho dos blocos, o número de validadores ativos e a topologia da rede P2P, afetam simultaneamente o volume de transações processadas por unidade de tempo e o tempo de confirmação percebido pelos usuários finais. A metodologia adotada combina revisão sistemática da literatura sobre modelos de desempenho em sistemas distribuídos e blockchains PoS, comparação de estudos empíricos que mensuram throughput e latência em plataformas públicas de referência – particularmente Ethereum pós-Merge, Solana e Polkadot – e análise conceitual dos trade-offs identificados. Os resultados obtidos sugerem que técnicas de otimização orientadas a parâmetros, tais como ajuste fino de tempos de slot e políticas de propagação acelerada de blocos, combinadas a inovações em camada de consenso – dentre as quais se destacam mecanismos híbridos com Proof of History e execução paralela de transações –, podem reduzir significativamente a latência de confirmação sem necessariamente comprometer a segurança criptográfica ou a robustez da rede. Entretanto, emergem limites estruturais associados à variabilidade de condições de rede em escala global, à heterogeneidade de capacidade computacional entre nós validadores e às exigências clássicas de tolerância a falhas bizantinas, os quais impõem fronteiras práticas ao ganho de throughput em ambientes permissionless. Conclui-se que uma abordagem sistêmica, que integre ajuste criterioso de parâmetros, desenho criterioso da infraestrutura de nós e mecanismos de monitoramento e benchmarking contínuos, é fundamental para o amadurecimento da infraestrutura Web3 e para o suporte a aplicações com requisitos estritos de qualidade de serviço, entre as quais se incluem protocolos de finanças descentralizadas, mercados de capitais tokenizados e aplicações sensíveis ao tempo.
Proof-of-Stake (PoS) networks rely on economic staking guarantees to align validator behavior with network security. However, a growing class of architectures permits validators to reuse, rehypothecate, or synthetically represent the same stake across multiple validation contexts. This paper defines <i>Double-Staking Validator Drift</i> as a structural vulnerability in which a validator’s effective economic exposure diverges from its apparent security contribution. We demonstrate how this drift undermines slashing guarantees, enables risk amplification, and creates false decentralization signals across PoS Layer-1 and restaking ecosystems. Existing mitigations—including slashing, social governance, and restaking policies—are shown to be insufficient due to enforcement blind spots and cross-domain opacity. We propose a logic-layer enforcement model that introduces validator-level stake exclusivity, temporal binding, and deterministic enforcement across consensus domains. This approach restores economic integrity to PoS security models and closes a critical gap in current network designs.
Blockchain networks have revolutionized decentralized applications but remain vulnerable to evolving security threats due to their reliance on static consensus mechanisms that cannot adapt to changing threat landscapes. This paper addresses this critical security gap by proposing Autonomous Defense-Adaptive Consensus Optimisation for Blockchain Networks (ADACON), an original framework for the dynamic adjustment of consensus mechanisms based on Bayesian threat detection. The research investigates how real-time adaptation between multiple consensus protocols can enhance blockchain resilience while maintaining performance. The approach integrates a Bayesian Threat Detector, Consensus Adapter, and Network State monitor in a modular architecture that continuously assesses network conditions and switches between five consensus mechanisms (PoW, PoS, PBFT, PoA, DPoS) as threats emerge. The framework was evaluated through comprehensive simulations involving 1,000 nodes, testing response to six distinct attack vectors, including Sybil, DoS, Byzantine, Eclipse, Majority, and Routing attacks. Results demonstrate that ADACON effectively identifies and responds to varied attacks with a latency of 29.7 ms and throughput of 833 TPS). Statistical validation across five independent simulation runs (seeds 5-9) confirmed framework reliability with consistent performance metrics (CV < 7.1% for latency, 5.4% for throughput). Delegated Proof of Stake emerged as the most frequently selected mechanism (23.2%) due to its balanced performance across multiple security dimensions. Significantly, the system exhibited greater adaptability and attack coverage than existing hybrid approaches. The previous high switching frequency was reduced by using hysteresis, i.e., by providing dwell time and an improved threshold that avoids unnecessary switching. The study concludes that dynamic consensus adaptation offers substantial security advantages for blockchain networks, particularly in high-security environments like financial systems and critical infrastructure. However, further research must focus on optimizing switching frequency and developing secure transition protocols to maximize effectiveness. ADACON represents an incremental extension tested toward more resilient blockchain systems that can autonomously respond to emerging threats while balancing security, performance, and resource utilization.
G.B. Bhavana, R. S. Anand, J. Ramprabhakar, Josep M. Guerrero · 6 authors
Integration of renewable-energy (RE) sources of energy into local microgrids, decentralised energy markets using blockchain based peer-to-peer (P2P) energy trading is gaining more traction due to its ability to enable transparent, autonomous, and secure transactions among distributed energy resources (DERs). Due to the large variety in microgrid topologies and their respective operational constraints, a key challenge to obtaining the most effective trading framework is the choice of blockchain consensus protocol that suits a given microgrid type. Choice of consensus mechanism solely affects the reliability and security of a network. This paper presents a quantitative comprehensive evaluation of various blockchain consensus mechanisms such as Proof-of-Work (PoW), Proof-of-Stake (PoS), Delegated Proof-of-Stake (DPoS), Proof-of-Elapsed-Time (PoET), Practical Byzantine Fault Tolerance (PBFT), Raft, and Tendermint to determine their suitability for P2P energy trading in microgrids. Various metrics such as fault tolerance, energy efficiency, latency, throughput and consensus time were evaluated for multiple consensus mechanisms through simulations. This paper also studies node-scaling impact on the protocols and presents a final decision framework to match the suitable protocol with various microgrid topologies.
Jorge Soria, Jorge Moya Velasco, Carlos Estévez-Mendoza
Decentralized Physical Infrastructure Networks (DePIN) represent an emerging organizational form for operating physical infrastructure through blockchain-based coordination. DePIN through decentralized protocols and token-based payment mechanisms incentivize independent agents to deploy, maintain, and monetize real-world infrastructure, such as wireless networks, storage units, or sensors. This article presents a first formal economic analysis of DePIN architectures, modelling investment decisions under network effects in a blockchain-native Decentralized Autonomous Organization (DAO), with protocol-defined reward schemes. It establishes the equilibrium conditions that support decentralized provision, where token prices internalize participation, service reliability, and network coverage. Furthermore, it identifies a minimum viable coverage threshold determined by costs and network effects. Through a multi-agent machine learning simulation, we confirm that decentralized provision improves efficiency compared to centralized models. The results support the economic viability of DePIN and provide design guidelines for future decentralized infrastructure protocols. Finally, we propose an DAO incentive mechanism to implement First Best provision in Decentralized Physical Infrastructure Networks.
Cardano, a major Proof-of-Stake (PoS) blockchain, aims to achieve decentralization through its reward distribution mechanism governed by the protocol parameter k, which defines the ideal number of reward-receiving stake pools. While k plays a critical role in shaping network dynamics, its current value is statically determined and lacks a formal theoretical basis.In this study, we conduct an empirical analysis of Cardano’s on-chain data to evaluate the effects of changing k on decentralization metrics such as the number of active pools, stake distribution, and the Nakamoto coefficient. Our findings show that while increasing k initially enhances decentralization, the long-term effects are limited due to dynamic shifts in pool performance and stake concentration.Based on these insights, we propose the foundation for a dynamic optimization framework that determines the appropriate value of k by integrating decentralization, operational cost, and behavioral factors. This work contributes to the development of sustainable and fair PoS governance through data-driven parameter tuning.
This paper presents a comparative analysis of three cryptographic approaches to securing fiber-optic data transmission: classical RSA/AES, Quantum Key Distribution (QKD) based on the E91 protocol, and Secure Dynamic Stream Encryption (SDSE). These are evaluated in terms of latency, key renewal frequency, computational load, energy efficiency, and resilience to quantum attacks. In addition to these core comparisons, we extend SDSE with a blockchain-based governance layer. This enhancement introduces auditable key management through distributed ledger technology (DLT), ensuring transparent tracking of key rotations, revocations, and policy enforcement without storing any secret material. The blockchain acts as a trust anchor for multi-node synchronization, particularly useful in federated or multi-domain environments. The combined SDSE + Blockchain framework provides a lightweight, quantum-resilient, and scalable encryption mechanism suitable for real-world deployment across conventional optical infrastructure.
Abstract Next generation wireless communications systems are rapidly penetrating higher RF frequency bands together with massive Multiple-Input-Multiple-Output (MIMO) communication schemes, requiring processing units to perform at millimeter-wave RF carriers while supporting high-bandwidth and highly scalable configurations. However, operating electronic MIMO processing units at such high-frequency and high-bandwidth system requirements becomes extremely challenging when targeting beneficial energy consumption metrics. Photonic processors emerge as a promising alternative to tackle channel interference encountered in MIMO systems, with the main argumentation building on the large available bandwidth and favorable energy efficiency credentials of Photonic Integrated Circuit (PIC) technologies. However, photonic MIMO processors that support more than 2 channels are currently entirely missing; moreover, their architectural framework relies exclusively on matrix decomposition algebra, raising significant concerns about their scalability potential. In this paper, we present a scalable silicon photonic (SiPho) MIMO processor architecture that exploits the coherent crossbar (Xbar) interferometric layout and demonstrates experimentally its successful performance in proof-of-concept MIMO setups. The zero-forcing photonic processor can cancel channel interference and compensate for phase offsets in the received signals. The experimental validation of the proposed system is performed through a 4×4 SiPho Xbar chip, demonstrating 3×3 and 4×4 MIMO processing with phase offset compensation capabilities for both single-tone and data-modulated RF channels, transmitted through arbitrary linear channels. This work presents, to the best of our knowledge, the largest demonstrated photonic MIMO processor, utilizing the SiPho Xbar linear optical circuit architecture and bearing the promise of scaling to more than 32 high-RF frequency and mmWave wireless channels.
Blockchain technology, particularly Ethereum, has enabled a wide range of decentralized applications but continues to face significant scalability challenges, including high gas fees, limited transaction throughput, and frequent network congestion. This review provides a comprehensive analysis of Ethereum's scalability constraints and critically evaluates current Layer 2 scaling solutions such as Rollups, Plasma, the Lightning Network, and other emerging alternatives. The study conducts a comparative assessment of these mechanisms with respect to decentralization, privacy, and security-core dimensions of the blockchain scalability trilemma. Recent academic contributions, including stochastic models of gas fee behavior and protocolspecific analyses, are examined to provide both theoretical and empirical insights. Emphasis is placed on understanding the architectural advantages of zk-Rollups and their positioning as a leading Layer 2 solution. Quantitative metrics such as transaction throughput benchmarks, privacy, and security capability comparisons are presented to support the evaluation. The findings are intended to inform the design of more scalable, secure, and privacy-preserving Ethereum-compatible architectures.