Blockchain Papers

Imran Khan, Sami Ur Rahman

No abstract is available for this record.

Ariy Khaerudin

The development of digital technology has driven the transformation of the global economy, including in Indonesia, through the commercialization of digital assets such as creative works, Non-Fungible Tokens (NFTs), and e-commerce platforms. However, the national legal system is still unable to accommodate these dynamics comprehensively. This study aims to analyze the effectiveness of legal protection of CopyrightCopyright as a digital asset in technology-based transactions, using normative legal methods and legislative, conceptual, and comparative legal approaches. The results of the study show that Law Number 28 of 2014 concerning Copyright and related regulations still has a gap in norms in dealing with new forms of digital intellectual property, weak law enforcement, and limited technical understanding by law enforcement officers. In addition, the less-than-optimal regulation in the financial, taxation, and personal data protection sectors increases the legal risks for digital economy actors, especially MSMEs and content creators. Therefore, responsive legal reforms are needed to strengthen the digital justice system, integrate technologies such as blockchain and AI, and increase legal literacy and coordination between institutions. This reform is important to create a fair, safe, and sustainable digital ecosystem that supports the growth of the national creative economy.

Imran Wajid, Danish Wajid, Bilal Wajid

In the world of increasing population with ever increasing strain on law enforcement agencies and judiciary, lack of imparting justice in time has become a major concern. The lack of timely justice has adversely affected the society’s ability to both administer and regulate public relations and affairs. In the middle of such concerns, Blockchain and Smart Contracts can play a pivotal role in managing society and ensuring a balance between criminal intent and legal sanction. Blockchain is a decentralized distributed framework where all nodes in the network collaborate on an equal footing to maintain necessary properties and functions. First introduced in 2008 via a seminal work ‘Bitcoin,’ the principles underlying cryptocurrency have shown immense potential. As of 2023, Blockchain is an institutional technology reshaping the current internet (web version 2.0) forcing it to evolve to web 3.0. It is the basis of ‘smart contracts,’ ‘distributed applications,’ ‘token economies and ‘decentralized autonomous organization.’ This paper dwells on two such applications, namely, cryptocurrency and smart contracts wherein we explain the technologies while highlighting legal challenges and open questions which need significant attention.

Preston Vander Vos

Users of blockchains value scalability, expecting fast confirmations and immediate transaction processing. Odontoceti, the latest in DAG-based consensus, addresses these concerns by prioritizing low latency and high throughput, making a strategic trade-off in security by operating with a 20% fault tolerance instead of the established 33% level. It is the first DAG-based protocol to achieve commitment in just two communication rounds, delivering median latency of 300 milliseconds while processing 10,000 transactions per second under realistic network conditions. Odontoceti operates with n = 5f + 1 validators and creates an uncertified DAG with a novel decision rule for committing blocks. The protocol includes an optimization that advances progress when participants are slow, benefiting crash fault scenarios which are more common in practice than Byzantine faults. Evaluation results demonstrate 20-25% latency improvements compared to an existing production protocol, validating that reducing wave length from three rounds to two rounds yields meaningful performance benefits. This paper establishes the practical viability of lower fault tolerance consensus protocols for blockchains.

Alexandre Pacheco, Hanqing Zhao, Volker Strobel, Tarik Roukny · 7 authors

Blockchain consensus, rooted in the principle ``don't trust, verify'', limits access to real-world data, which may be ambiguous or inaccessible to some participants. Oracles address this limitation by supplying data to blockchains, but existing solutions may reduce autonomy, transparency, or reintroduce the need for trust. We propose Swarm Oracle: a decentralized network of autonomous robots -- that is, a robot swarm -- that use onboard sensors and peer-to-peer communication to collectively verify real-world data and provide it to smart contracts on public blockchains. Swarm Oracle leverages the built-in decentralization, fault tolerance and mobility of robot swarms, which can flexibly adapt to meet information requests on-demand, even in remote locations. Unlike typical cooperative robot swarms, Swarm Oracle integrates robots from multiple stakeholders, protecting the system from single-party biases but also introducing potential adversarial behavior. To ensure the secure, trustless and global consensus required by blockchains, we employ a Byzantine fault-tolerant protocol that enables robots from different stakeholders to operate together, reaching social agreements of higher quality than the estimates of individual robots. Through extensive experiments using both real and simulated robots, we showcase how consensus on uncertain environmental information can be achieved, despite several types of attacks orchestrated by large proportions of the robots, and how a reputation system based on blockchain tokens lets Swarm Oracle autonomously recover from faults and attacks, a requirement for long-term operation.

Qianyu Yu, Giuliano Losa, Nibesh Shrestha, Xuechao Wang

To maximize performance, many modern blockchain systems rely on eventually-synchronous, Byzantine fault-tolerant (BFT) consensus protocols. Two protocol designs have emerged in this space: protocols that minimize latency using a leader that drives both data dissemination and consensus, and protocols that maximize throughput using a separate, asynchronous data dissemination layer. Recent protocols such as Partially-Synchronous Bullshark and Sailfish combine elements of both approaches by using a DAG to enable parallel data dissemination and a leader that paces DAG formation. This improves latency while achieving state-of-the-art throughput. Yet the latency of leader-based protocols is still better under moderate loads, which are common in practice. We present Angelfish, a hybrid protocol that adapts smoothly across this design space, from leader-based to Sailfish-like DAG-based consensus. Angelfish lets a dynamically adjusted subset of parties use best-effort broadcast to issue lightweight votes instead of reliably broadcasting costlier DAG vertices. This reduces communication, helps lagging nodes catch up, and lowers latency in practice compared to prior DAG-based protocols. Our empirical evaluation shows that Angelfish attains state-of-the-art peak throughput while significantly lowering latency under moderate throughput, delivering the best of both worlds.

Toby Sharp

Bitcoin's consensus rules are encoded in the implementation of its reference client: "The code is the spec." Yet this code is unsuitable for formal verification due to side effects, mutable state, concurrency, and legacy design. A standalone formal specification would enable verification both across versions of the reference client and against new client implementations, strengthening decentralization by reducing the risk of consensus-splitting bugs. Yet such a specification has long been considered intractable given the complexity of Bitcoin's consensus logic. We demonstrate a compact, executable, declarative C++ specification of Bitcoin consensus rules that syncs mainnet to tip in a few hours on a single thread. We also introduce the Hornet Domain-Specific Language (DSL) specifically designed to encode these rules unambiguously for execution, enabling formal reasoning, consensus code generation, and AI-driven adversarial testing. Our spec-driven client Hornet Node offers a modern and modular complement to the reference client. Its clear, idiomatic style makes it suitable for education, while its performance makes it ideal for experimentation. We highlight architectural contributions such as its layered design, efficient data structures, and strong separation of concerns, supported by production-quality code examples. We argue that Hornet Node and Hornet DSL together provide the first credible path toward a pure, formal, executable specification of Bitcoin consensus.

Nur Aqilah Hazirah Mohd Anim

Blockchain technology has become a foundational innovation in digital systems, offering unique features that address trust, transparency, and security in decentralized environments. Despite its increasing application across diverse fields such as supply chain, finance, and e-government, the academic literature reflects inconsistency in defining and operationalizing blockchain’s core characteristics. This study conducts a semi-systematic review to synthesize and classify the commonly cited characteristics of blockchain. Drawing from academic sources across multiple domains, the review categorizes these characteristics into core (e.g., decentralization, transparency), peripheral (e.g., privacy, scalability), and technical (e.g., programmability, tokenization) traits. The paper highlights areas of convergence and divergence and proposes a taxonomy to guide future research and instrument development. The findings offer a clearer conceptual foundation for evaluating blockchain systems and support the creation of standardized measurement tools for empirical investigations.

Vladyslav Ograzansky, Yurii Yushchyk

The article examines the development of local budgets in Ukraine in the context of local government reform and the implementation of budget decentralization. Theoretical approaches to determining the essence and role of local budgets in the public finance system, as key instruments for financing the socio-economic development of territorial communities, are substantiated. The regulatory and legal principles governing the formation and implementation of local budgets are analyzed, their transformation under the influence of decentralization processes is determined, and the main legislative gaps hindering the increase in the financial autonomy of local government bodies are identified. The impact of local government reform on the financial capacity of territorial communities is assessed by examining changes in the revenue and expenditure structure of local budgets, the ratio of own revenues to inter-budgetary transfers, and the expansion of budgetary powers at the local level. It is established that budget decentralization has generally expanded the role of local budgets in financing public services, but its effects are uneven and largely depend on the economic potential of the territories. Key problems and systemic imbalances in the development of local budgets in modern socio-economic conditions have been identified, including structural inequality in the income base of communities, an imbalance between delegated powers and financial resources, persistent transfer dependence, and managerial and demographic constraints. The need to transition from the formal expansion of budget powers to the qualitative strengthening of the financial capacity of territorial communities by improving inter-budgetary equalization mechanisms, stimulating own revenues, and increasing the effectiveness of budgetary resource use has been substantiated. Keywords: local budgets, budget decentralization, local self-government, financial capacity, territorial communities, public finances.

Yadiki Bhavashya Chandra

Digital payments have grown exponentially but face risks such as fraud, account takeover, and unauthorized transactions. This paper explores how blockchain technology, with its decentralized ledger, cryptographic integrity, and smart contracts, can secure digital payments and prevent fraud. We propose a permissioned blockchain architecture for payment systems, integrating identity management, escrow-based smart contracts, and audit-ready transaction logs. Illustrative simulations compare fraud-risk indices, transaction confirmation time, and per-transaction cost across traditional payment gateways and blockchain systems. The results indicate that blockchain can reduce fraud exposure while maintaining near real-time settlement. Challenges such as scalability, privacy, and regulatory compliance are also discussed. This study highlights blockchain?s potential as a preventive, secure mechanism for digital payments and sets the stage for future research integrating zero-knowledge proofs and federated learning.

Karan B Patel

The problem of surprise medical billing has become quite ubiquitous in the American healthcare system, impacting the wallets of insured citizens adversely as they unknowingly seek the services of providers who are out of network. Although the No Surprises Act has created federal safeguards to prevent surprise bills, there are portions in the regulatory system that have not been addressed sufficiently, and a system-wide approach is needed for technical solutions. The approach is transformative as the Integrated Financial Systems (IFS) are increasingly offered on the basis of advanced interoperability standards like Fast Healthcare Interoperability Resources (FHIR) and promising emerging technologies such as blockchain and distributed ledger systems. These technologies bring more transparent, efficient, and secure healthcare billing ecosystems, which are beneficial to all stakeholders because patients achieve greater financial clarity and simplified billing procedures, providers realize a streamlined approach to revenue cycle management and fewer administrative tasks, and insurers achieve faster claims processing and fraud detection. The rise of IFS brings with it critical, ethically-driven concerns surrounding algorithmic decision-making and data privacy that would require the implementation of explainable AI, routine bias evaluation, and human judgment via Human-in-the-Loop frameworks to warrant fair results among various patient groups.

YuDi Feng, Bin Shen, LongJie Liu, Tian Zhou

Currently, urban renewal projects primarily rely on traditional financing methods such as government fiscal support, bank loans, and corporate self-funding. However, these models exhibit significant limitations. As urban renewal progresses towards high-quality development, there is an urgent need to explore innovative financing m echanisms t hat o ffer g reater efficiency, transparency, and sustainability. In this context, the introduction of blockchain technology presents a novel breakthrough for urban renewal financing. The decentralized, immutable, and smart contract-enabled features of blockchain can optimize capital flow, e nhance c redit s ystems, reduce fi nancing co sts, an d attract more social capital participation. By leveraging blockchain and Interplanetary file s ystem ( IPFS) t echnologies, i t i s p ossible to achieve full traceability of fund flows among government entities, financial institutions, enterprises, and investors, thereby reducing information asymmetry and strengthening mutual trust. Real-time on-chain recording of fund utilization ensures dedicated use of funds, prevents misappropriation or abuse, and improves the efficiency o f b oth fi scal re sources an d so cial ca pital. Moving forward, it is essential to integrate policy support with technological pilots to gradually construct a "blockchain + urban renewal" digital financial i nfrastructure, p roviding n ew m omentum for high-quality urban development.

Alina Kovach

The article is devoted to the theoretical and methodological justification of the impact of decentralization reform on the financial capacity of rural communities using the example of Zakarpattia Oblast in the context of martial law and profound socio-economic transformations. The content of decentralization as a key element of multi-level public administration is revealed, and its role in redistributing powers, resources, and responsibilities between the central government and local self-government, as well as in the formation of capable territorial communities, is clarified. Based on the Constitution of Ukraine, the fundamental laws on local self-government, and strategic documents of state regional policy, the institutional foundations of financial decentralization and the formation of local budgets’ revenue base are analyzed. A methodological approach to assessing the financial capacity of communities is proposed, based on the use of an integral index and a system of eleven indicators (revenues, expenditures, budget structure, share of transfers, capital investments, etc.), considering data from the ULEAD with Europe program and the specifics of the war period. Based on empirical data from 2023–2024, differences in financial capacity across rural, settlement, and urban communities were revealed. Trends in the share of communities with high, optimal, satisfactory, low, and critical levels of capacity were outlined, including a decrease in the share of critically weak communities and a gradual strengthening of individual rural communities. Specific attention is paid to the analysis of the financial situation in the communities of Zakarpattia Oblast, where both deterioration in indicators for individual territories and positive examples of capacity growth through intermunicipal cooperation, participation in international projects, and the intensification of local economic development have been recorded. The expediency of using an integrated financial capacity index as a tool for monitoring and justifying targeted state and regional policy measures to support rural communities is demonstrated. Keywords: decentralization, capacity, socio-economic development, finance, rural areas, territorial communities, competitiveness.

Selvaragavan S, Karuppasamy L, Yuvan Sankar NKR, R Sylaja Vallee Narayan S. · 6 authors

The Internet of Things (IoT) has significantly transformed critical domain such has healthcare, transportation, industry, and smart cities by connecting billions of devices that can gather and share data. However, as it grows rapidly, IoT systems are grappling with significant issues around data security, user privacy, and trust. Centralized systems are particularly at risk due to single points of failure, latency issues, and potential privacy breaches, which makes them less ideal for large-scale use. While blockchain technology provides a way to decentralize and resist tampering, traditional frameworks can be too resource-heavy and impractical for low-power IoT devices.This paper introduces a Lightweight Blockchain Framework designed for Secure and Privacy-Preserving IoT Systems. It combines energy-efficient consensus mechanisms, trust-based reputation management, and a hybrid approach to on-chain and off-chain storage. By utilizing edge-assisted processing, we can cut down on computational demands, and cryptographic techniques like elliptic curve cryptography and zero-knowledge proofs help maintain privacy during authentication. The framework is built with scalability, low latency, and effective communication in mind, making it suitable for real-time IoT applications.Simulation results show that our proposed framework can reduce communication costs by 35%, lower latency, and improve privacy protection compared to traditional blockchain-based IoT systems. These findings indicate that the framework is not only lightweight and secure but also practical for applications that need privacy and quick responses, such as in healthcare, industrial automation, and smart infrastructure.

Benjamin Mudiangombe Mudiangombe, John Weirstrass Muteba Mwamba

This study explores the new insights into the integration and dynamic asymmetric volatility risk spillovers between Bitcoin, currency pairs (USD/ZAR, GBP/ZAR and EUR/ZAR), and traditional financial assets (ALSI, Bond, and Gold) in South Africa using daily data spanning the period from 2010 to 2024 and employing Time-Varying Parameter Vector Autoregression (TVP-VAR) and wavelet coherence. The findings revealed strengthened integration between traditional financial assets and currency pairs, as well as weak integration with BTC/ZAR. Furthermore, BTC/ZAR and traditional financial assets were receivers of shocks, while the currency pairs were transmitters of spillovers. Gold emerged as an attractive investment during periods of inflation or currency devaluation. However, the assets have a total connectedness index of 28.37%, offering a reduced systemic risk. Distinct patterns were observed in the short, medium, and long term in time scales and frequency. There is a diversification benefit and potential hedging strategies due to gold’s negative influence on BTC/ZAR. Bitcoin’s high volatility and lack of regulatory oversight continue to be deterrents for institutional investors. This study lays a solid foundation for understanding the financial dynamics in South Africa, offering valuable insights for investors and policymakers interested in the intricate linkages between BTC/ZAR, currency pairs, and traditional financial assets, allowing for more targeted policy measures.

Arthur Rodrigues Pereira de Carvalho, Felipe Quintino, Helton Saulo, Luan Carlos de Sena Monteiro Ozelim · 6 authors

This study introduces and evaluates stochastic models to describe Bitcoin price dynamics at different time scales, using daily data from January 2019 to December 2024 and intraday data from 20 January 2025. In the daily analysis, models based on are introduced to capture long memory, paired with both constant-volatility (CONST) and stochastic-volatility specifications via the Cox–Ingersoll–Ross (CIR) process. The novel family of models is based on Generalized Ornstein–Uhlenbeck processes with a fluctuating exponential trend (GOU-FE), which are modified to account for multiplicative fBm noise. Traditional Geometric Brownian Motion processes (GFBM) with either constant or stochastic volatilities are employed as benchmarks for comparative analysis, bringing the total number of evaluated models to four: GFBM-CONST, GFBM-CIR, GOUFE-CONST, and GOUFE-CIR models. Estimation by numerical optimization and evaluation through error metrics, information criteria (AIC, BIC, and EDC), and 95% Expected Shortfall (ES95) indicated better fit for the stochastic-volatility models (GOUFE-CIR and GFBM-CIR) and the lowest tail-risk for GOUFE-CIR, although residual analysis revealed heteroscedasticity and non-normality. For intraday data, Exponential, Weibull, and Generalized Gamma Autoregressive Conditional Duration (ACD) models, with adjustments for intraday patterns, were applied to model the time between transactions. Results showed that the ACD models effectively capture duration clustering, with the Generalized Gamma version exhibiting superior fit according to the Cox–Snell residual-based analysis and other metrics (AIC, BIC, and mean-squared error). Overall, this work advances the modeling of Bitcoin prices by rigorously applying and comparing stochastic frameworks across temporal scales, highlighting the critical roles of long memory, stochastic volatility, and intraday dynamics in understanding the behavior of this digital asset.

Esmeide Leal

Non-Fungible Tokens (NFTs) have emerged as a transformative blockchain-based technology, enabling unique digital ownership and novel applications across art, gaming and Decentralized Finance (DeFi).However, the rapid evolution of NFT ecosystems has exposed critical challenges in scalability, security and interoperability, driven by the underlying blockchain architectures and software design paradigms.This article presents a systematic review of state-of-the-art blockchain architectures supporting NFTs, analyzing Layer-1 and Layer-2 solutions, consensus mechanisms and smart contract design patterns.We further explore software design best practices for NFT platforms, including gas optimization, upgradeability and anti-fraud mechanisms.Through a comparative analysis of Ethereum, Solana, Flow and Layer-2 frameworks like Polygon, we identify trade-offs in decentralization, throughput and cost.Finally, we highlight open challenges and future directions, such as cross-chain interoperability and energy-efficient NFT minting.This work serves as a comprehensive reference for researchers and practitioners aiming to advance NFT infrastructure.

Harshvardhan Dixit, Paras Jain, Mukul Aggarwal, Divyanshu Shukla

Non-fungible tokens (NFTs) are digital assets stored digitally that define digital creative works or intellectual assets, such as the “soundtrack,” “digital artworks,” “games,” “animated gifs,” and “short video clips.” Fungible means to mention that an asset's units are all the same, interchangeable, and dividable.NFT marketplaces are online platforms that have the capability of transforming global interaction and ownership. Although there have been challenges, relentless innovation and collaboration have the potential to bring NFTs to full fruition. By engaging in regulatory, security, scalability, and valuation issues, the industry has the ability to facilitate and sustain mass NFT market use. The study concentrated on identifying several use cases for NFTs and analyzing their potential for creators in the marketplace. The purpose of this paper is to provide a foundational understanding of NFTs and their market applications. The current global market capitalization of NFTs is $60 billion, which is approaching the $100 billion global market capitalization of art.

Swagatika Sahoo, Raju Halder, Samrat Mondal

No abstract is available for this record.

Vabuk Pahari, Andrea Canidio

We analyze 15,097 blocks proposed for inclusion in Ethereum's blockchain over an eight-minute window on December 3, 2024, during which 38 blocks were added to the chain. We classify transactions as exclusive -- appearing only in blocks from a single builder -- or private -- absent from the public mempool but included in blocks from multiple builders. We find that, depending on the methodology, exclusive transactions account for between 77.2% and 84% of the total fees paid by transactions in winning blocks. Moreover, we show that exclusivity cannot be fully attributed to persistent relationships between senders and builders: only between 7% and 8.4% of all on-chain exclusive transaction value originates from senders who route exclusively to one builder. Finally, we observe that transaction exclusivity is dynamic. Some transactions are exclusive at the start of a bidding cycle but later appear in blocks from multiple builders. Other transactions remain exclusive to a losing builder for two or three cycles before appearing in the public mempool. These transactions are therefore delayed and then exposed to potential attacks.

Mohamed Abdessamed Rezazi, Mouhamed Amine Bouchiha, A. Bendada, Yacine Ghamri-Doudane

Roaming settlement in 5G and beyond networks demands secure, efficient, and trustworthy mechanisms for billing reconciliation between mobile operators. While blockchain promises decentralization and auditability, existing solutions suffer from critical limitations-namely, data privacy risks, assumptions of mutual trust, and scalability bottlenecks. To address these challenges, we present B5GRoam, a novel on-chain and zero-trust framework for secure, privacy-preserving, and scalable roaming settlements. B5GRoam introduces a cryptographically verifiable call detail record (CDR) submission protocol, enabling smart contracts to authenticate usage claims without exposing sensitive data. To preserve privacy, we integrate non-interactive zero-knowledge proofs (zkSNARKs) that allow on-chain verification of roaming activity without revealing user or network details. To meet the high-throughput demands of 5G environments, B5GRoam leverages Layer 2 zk-Rollups, significantly reducing gas costs while maintaining the security guarantees of Layer 1. Experimental results demonstrate a throughput of over 7,200 tx/s with strong privacy and substantial cost savings. By eliminating intermediaries and enhancing verifiability, B5GRoam offers a practical and secure foundation for decentralized roaming in future mobile networks.

Detian Liu, Jianbiao Zhang, Yifan Wang, Hong Shen · 6 authors

Smart contracts, as self-executing agreements on blockchain platforms, promise to eliminate intermediaries and enhance transaction efficiency. However, their susceptibility to security vulnerabilities not only poses risks of substantial financial losses but also erodes trustworthiness in blockchain ecosystems, driving extensive research into enhancing both their security and trustworthiness. We provide a comprehensive review of the current state of smart contract assurance, covering the primary security threats and mitigation strategies throughout the contract lifecycle–from development to deployment, execution, and maintenance. It evaluates both established and advanced vulnerability detection techniques while exploring underexamined areas, including automated repair, secure execution environments, and defenses against malicious attacks. We further propose a framework to ensure the holistic security and trustworthiness of smart contracts, and discuss future directions for research and development, emphasizing the need to address both technical and regulatory challenges to promote widespread adoption.

Inas Al Khatib, Malick Ndiaye

Bad medical debt negatively impacts individuals' physical and mental well-being, can discourage future care-seeking, and is increasingly viewed as a social determinant of health. Addressing this issue by linking the healthcare sector with humanitarian efforts presents a significant global challenge, requiring innovative solutions. This paper aims to synthesize existing literature on the topic. Using the Scopus database, a systematic review of literature was conducted from 1990 to 2024, employing the PRISMA framework. Thematic analysis was applied to organize and interpret the findings. Reviewing 958 papers, including 318 key sources, revealed a pressing need for a SMART blockchain healthcare platform. Such a platform would securely connect beneficiaries with philanthropists, facilitate data sharing, and align donor requirements with beneficiary criteria. Employing decentralized autonomous organization frameworks and smart contracts ensures transparency, efficiency, and accountability through automated and secure processes.

G Anvith, Nithish Kushal Reddy, Ragini Tripathi, C. R. Kavitha

Federated learning enables multiple clients to collaboratively train a shared model without exchanging raw data, but it raises privacy and integrity concerns when model updates traverse untrusted channels. In this project, we develop a secure federated learning pipeline that combines the CKKS homomorphic-encryption scheme with Groth-16 zero-knowledge proofs to protect client updates during transmission and to verify that each update stays within an agreed-upon norm bound. We benchmark CKKS parameters (poly_modulus degree, coefficient_moduli, and scale) on real-world model vectors to identify an optimal setting—8192-degree with two primes (60-bit and 40-bit) at a 232scale—that offers sub-100 ms encryption, minimal error, and moderate ciphertext sizes ( 3.3 MB). Clients train a small convolutional network on disjoint partitions of the MSTAR SAR dataset, generate succinct ZK proofs for each 128-element weight chunk, encrypt those chunks under the selected CKKS context, and submit both ciphertexts and proofs to dedicated servers. The homomorphic-aggregation server sums encrypted updates, while the ZKP server enforces correctness by rejecting any proof that violates the norm constraint—demonstrated by catching an intentionally malicious client. End-to-end testing confirms that the combined CKKS+ZKP pipeline preserves model accuracy and ensures both confidentiality and integrity of federated updates.