Blockchain Papers

Yuqi Zhao, Zhiming Song, Junrong Song, Hui Tong · 6 authors

No abstract is available for this record.

Carmen Bisogni, Aniello Castiglione, Maddalena Migliaccio, Annalaura Miglino · 5 authors

This paper presents a legal and privacy-preserving use of a covert channel built over BLE, specifically between two Android devices. A custom communication protocol has been designed and implemented through a dedicated mobile application, leveraging BLE advertisement packets for unidirectional message exchange. The protocol integrates non-interactive Zero-Knowledge Proofs (ZKPs) to strengthen the authentication mechanism while preserving anonymity. This allows the receiver to verify the sender’s legitimacy without revealing or exchanging identifying information, achieving blind authentication in a fully connectionless and decentralized architecture. The resulting system enables encrypted, anonymous, and verifiable communication over BLE without pairing or persistent sessions. Experimental validation confirms the protocol’s feasibility, efficiency, and resilience against common wireless threats like spoofing, replay, and message injection. This work demonstrates how BLE and ZKP can be combined to form a secure, privacy-preserving covert communication framework applicable in real-world mobile environments.

Authors unavailable

India’s dynamic socio-economic landscape and vast geography necessitate efficient and equitable public service delivery mechanisms, especially in areas like inter-state travel for citizens eligible for complimentary or concessional passes. Traditional systems used for issuing such privilege passes suffer from inefficiencies, fraud vulnerabilities, and inconsistent verification standards across states. This paper proposes a novel smart contract- based authentication mechanism built on a permissioned blockchain architecture to automate and secure the issuance of privilege passes for inter-state travel within India. By integrating Aadhaar-based digital identity verification and leveraging the immutability and transparency of blockchain, this approach enables real-time, verifiable, and tamper-proof pass issuance, while minimizing administrative overhead. The proposed system operates through a consortium-led blockchain network composed of central and state transport authorities and public sector technology partners. Smart contracts deployed on this network enforce eligibility rules automatically by interacting with off-chain data sources—referred to as oracles—that provide income, age, or employment status of applicants. Once eligibility is validated, a digital privilege pass is issued, cryptographically linked to the citizen’s identity and stored on-chain. These digital passes can be presented through QR codes and verified instantly by transport officials using mobile applications. Key features of this system include tamper-resistant records, zero-knowledge proof support for privacy preservation, and revocation capabilities for dynamic eligibility management. Aadhaar e-KYC ensures that only legitimate individuals are granted benefits, while the use of hashed identifiers on-chain preserves personal privacy. Furthermore, the permissioned nature of the blockchain network ensures compliance with national data protection laws while allowing rapid consensus and controlled access. By introducing automation, auditability, and interoperability into the travel concession ecosystem, this framework significantly reduces the risk of misuse, streamlines citizen experience, and enhances governance efficiency. The solution supports pan-India applicability and is adaptable to the varied policy rules across different states. Its modular design also enables future expansion to other welfare services, such as subsidized healthcare or education benefits. This paper outlines the technical architecture, smart contract workflow, governance model, and potential challenges in implementing such a system. The integration of decentralized technologies in public service infrastructure marks a progressive step toward a transparent, efficient, and citizen-centric Digital India.

Biagio Boi, Franco Cirillo, Marco De Santis, Christian Esposito

Digital health services for disease diagnosis, followup, and patient empowerment manage data that belongs to a special class of personal information, according to the General Data Protection Regulation (GDPR). For this reason, user authentication and access control are among the key security measures suggested for their protection. However, in the medical context, it is crucial to balance security and privacy support with timeliness and ease of access, which requires innovative solutions. This manuscript introduces an innovative approach leveraging Soulbound Tokens (SBTs) and Zero-Knowledge Proofs (ZKPs), particularly zk-SNARKs, to provide a privacy-aware mechanism for patient authentication in the medical domain. SBTs are utilized within an Attribute-Based Access Control (ABAC) model, ensuring that only eligible patients can access specific medical treatments. In a treatment-specific model, an SBT is issued for each diagnosis, allowing precise control but increasing management complexity. Alternatively, in a diagnosis-categorybased model, SBTs are grouped by diagnostic categories. This reduces the number of tokens and optimizes the space in the patient's wallet but sacrifices some precision in the information. Results demonstrate the timeliness of the proposed approach, with an average time of 6.82s for the release of an SBT and a maximum on-chain verification time of 15.04ms, showcasing their future adoption in a real-time environment, such as the medical context.

Filippo Scaramuzza, Giovanni Quattrocchi, Damian A. Tamburri

As Artificial Intelligence (AI) systems, particularly those based on machine learning (ML), become integral to high-stakes applications, their probabilistic and opaque nature poses significant challenges to traditional verification and validation methods. These challenges are exacerbated in regulated sectors requiring tamper-proof, auditable evidence, as highlighted by apposite legal frameworks, e.g., the EU AI Act. Conversely, Zero-Knowledge Proofs (ZKPs) offer a cryptographic solution that enables provers to demonstrate, through verified computations, adherence to set requirements without revealing sensitive model details or data. Through a systematic survey of ZKP protocols, we identify five key properties (non-interactivity, transparent setup, standard representations, succinctness, and post-quantum security) critical for their application in AI validation and verification pipelines. Subsequently, we perform a follow-up systematic survey analyzing ZKP-enhanced ML applications across an adaptation of the Team Data Science Process (TDSP) model (Data & Preprocessing, Training & Offline Metrics, Inference, and Online Metrics), detailing verification objectives, ML models, and adopted protocols. Our findings indicate that current research on ZKP-Enhanced ML primarily focuses on inference verification, while the data preprocessing and training stages remain underexplored. Most notably, our analysis identifies a significant convergence within the research domain toward the development of a unified Zero-Knowledge Machine Learning Operations (ZKMLOps) framework. This emerging framework leverages ZKPs to provide robust cryptographic guarantees of correctness, integrity, and privacy, thereby promoting enhanced accountability, transparency, and compliance with Trustworthy AI principles.

Ken Huang, Vineeth Sai Narajala, John Yeoh, Jason Ross · 9 authors

Traditional Identity and Access Management (IAM) systems, primarily designed for human users or static machine identities via protocols such as OAuth, OpenID Connect (OIDC), and SAML, prove fundamentally inadequate for the dynamic, interdependent, and often ephemeral nature of AI agents operating at scale within Multi Agent Systems (MAS), a computational system composed of multiple interacting intelligent agents that work collectively. This paper posits the imperative for a novel Agentic AI IAM framework: We deconstruct the limitations of existing protocols when applied to MAS, illustrating with concrete examples why their coarse-grained controls, single-entity focus, and lack of context-awareness falter. We then propose a comprehensive framework built upon rich, verifiable Agent Identities (IDs), leveraging Decentralized Identifiers (DIDs) and Verifiable Credentials (VCs), that encapsulate an agents capabilities, provenance, behavioral scope, and security posture. Our framework includes an Agent Naming Service (ANS) for secure and capability-aware discovery, dynamic fine-grained access control mechanisms, and critically, a unified global session management and policy enforcement layer for real-time control and consistent revocation across heterogeneous agent communication protocols. We also explore how Zero-Knowledge Proofs (ZKPs) enable privacy-preserving attribute disclosure and verifiable policy compliance. We outline the architecture, operational lifecycle, innovative contributions, and security considerations of this new IAM paradigm, aiming to establish the foundational trust, accountability, and security necessary for the burgeoning field of agentic AI and the complex ecosystems they will inhabit.

M. Gokul

Traditional voting systems face significant challenges, including susceptibility to fraud, lack of transparency, and privacy concerns. Centralized electronic voting systems, while improving accessibility, often suffer from vulnerabilities such as tampering, single points of failure, and insufficient auditability. This project proposes a blockchain-based distributed electronic voting system that leverages smart contracts to ensure voter privacy, ballot integrity, and decentralized verification. The system employs cryptographic techniques such as zero-knowledge proofs (ZKPs) to anonymize voter identities while maintaining a verifiable audit trail on an immutable blockchain ledger. Smart contracts automate vote tallying, enforce voting rules (e.g., eligibility checks, one-vote-per- voter), and ensure tamper-proof execution of electoral processes. A permissioned blockchain network enhances scalability and reduces energy consumption compared to public blockchains. The system also incorporates multi-factor voter authentication and end- to-end encryption to safeguard against unauthorized access. By decentralizing control and enabling real-time transparency, this solution addresses critical flaws in existing systems, reduces electoral fraud, and strengthens public trust in democratic processes. The proposed architecture is implemented using Hyperledger Fabric for blockchain operations and Ethereum-based smart contracts, ensuring high performance, security, and compliance with electoral regulations.

M. Sathyanarayanan, Usha Bala Varanasi, Inderpreet Kaur, Rajkumar Chadge · 6 authors

Online growth leads organizations to demand protected systems that protect privacy while managing identities. Traditional identity systems maintain centralized control that exposes users to data breaches while requiring new security solutions. A blockchain-enabled identity management solution was designed to implement zero-knowledge proofs (ZKP) for authentication methods with distributed execution of user credentials. The system uses Ethereum alongside Hyperledger Fabric platforms and runs simulations through Hyperledger Caliper platforms. The results demonstrate significant improvements in key performance metrics: The system delivered verification accuracy at 98.7% privacy leakage reached 0.05% while transaction latency fell under 125 ms and TPS scalability reached 950. The proposed model delivered superior privacy guarantees and operating efficiency. Future advancements in decentralized identity management build upon a reliable platform that ensures both privacy preservation and secure identity solutions.

Eber J. Ávila-Martínez, G L K Niharika, Arutchelvi Jayaraj

Voting is the most important topic for societal concern. Nowadays voting is considered as important and mandatory for all the citizens of India. So, compared with the traditional methods, E Voting is considered as the best option for voting mechanism as it is cost efficient, easy accessibility and convenient for every citizen in India. Therefore, E-Voting is mainly focused on Security and these security issues are considered as major drawbacks. To eradicate this factor, Blockchain came up with the idea of Quantum-Resistant Zero-Knowledge Proof Algorithm (QRZ-KPA). QRZ-KPA uses cryptographic and hashing strategies to make a secure and safe voting process. It also safeguards unauthorized users and voters to access it by ensuring the authenticity of the voter without revealing the personal information of the voters by using zero knowledge algorithm. Thus, the QR-ZKPA algorithm ensures the safe and integrated voting process and becomes a strong solution for the challenges and drawbacks faced by the online voting system. Hence, this algorithm provides the safe voting process in democratic process. Furthermore, QR-ZKPA is stronger with the combination of the Isolation Forest (iForest) machine mastering algorithm to identify irregularities and anomalies in vote casting styles, thereby similarly fortifying the system’s defenses in opposition to false sports. This technique offers good protection against vote manipulation, double balloting, unauthorized entry to, and other capability dangers. Our assessments illustrate the combined effectiveness of QR-ZKPA and iForest in enhancing the integrity, confidentiality, and security of blockchain-based totally e-balloting systems, guaranteeing their durability and dependability in a put upquantum environment.

Niraj Upadhayaya, Pramod Kumar

To tackle the privacy protection and efficiency challenges within the block-chain domain, this chapter introduces a privacy-enhancing solution for copyright blockchains, integrating lightweight homomorphic encryption and zero-knowledge proofs. This innovative approach enhances homomorphic encryption algorithms to streamline key generation and encryption processes while incorporating zero-trust security principles to curtail unnecessary homomorphic operations. Following the application of lightweight homomorphic encryption, sensitive data is transformed into ciphertext and securely added to the blockchain ledger by nodes authorized for accounting purposes. This solution not only rectifies the inherent drawbacks of complete data transparency in blockchain networks but also enhances operational efficiency. Security analysis underscores its qualities, including resistance to tampering and data privacy preservation. Through both performance simulations and theoretical deductions, the paper demonstrates that this approach mitigates efficiency challenges related to the distribution, sharing, and computation of private data in ciphertext form. Ultimately, this proposed methodology proves more effective in upholding customer privacy than traditional digital copyright models.

R. N. Kulkarni, Chetna Kaushal, Ismail Keshta, Mukesh Soni · 5 authors

As a prime exemplar of the Internet of Things (IoT), the vehicle-to-vehicle network assumes a pivotal position in the realm of intelligent transportation. It provides various online services for vehicles and reduces the risk of accidents for drivers. However, during communication, the vehicle-to-vehicle network generates sensitive information, such as vehicle location and routes. Enhancing the anonymity of vehicle identities in secure services is a research interest in vehicle-to-vehicle network security, especially in Zero Trust network security. This article introduces an anonymous identity authentication scheme based on batch verification algorithms, leveraging the principles of Zero Trust security. It expands the scope of anonymous authentication methods for IEEE WAVE security services by incorporating techniques such as anonymous credentials and zero-knowledge proofs, in accordance with the tenets of the Zero Trust model. Furthermore, it offers a mechanism for identity recovery via a trusted third party, thereby establishing a holistic 186 security framework. Experimental results indicate that when the number of signatures for batch verification exceeds 11, the computational cost of the proposed scheme is more efficient than some comparative schemes. Based on this, the article suggests the optimal cycle for batch verification in the DSRC’s BSM and vehicle proximity payment applications while maintaining a zero-trust security posture.

MOSAHEB, Rafieh

Electronic voting (e-voting) has emerged as a transformative technology in the modern digital era. Many countries across the world are using e-voting systems in different types of elections, from political to non-political. One of the primary goals of e-voting is ensuring both verifiability and privacy simultaneously, which we refer to as security. Verifiability is a security feature that guarantees voters can confirm their vote is reflected in the final election result, while privacy guarantees that no one is able to link a vote to the voter who cast it. Verifiability needs to hold only for the duration of the election, whereas privacy needs to extend beyond the election period, even decades after the election. This property, known as everlasting privacy in the literature, ensures that even computationally unbounded adversaries cannot compromise voter privacy, securing elections against future advances in computing, including quantum computing. Researchers have proposed a wide variety of protocols to achieve this ambitious goal in secure e-voting, however, these protocols differ significantly, making the analysis and state-of-the-art complicated. In this thesis, we first address this fragmentation by systematically analyzing all existing e-voting protocols designed to ensure everlasting privacy. We map out the relationships and dependencies among these protocols, evaluate their security and efficiency under realistic assumptions, and identify unresolved challenges in the field. Our work provides a foundational reference for researchers aiming to design secure e-voting systems with everlasting privacy, paving the way for privacypreserving elections in the post-quantum era. Building on these insights, we propose a novel e-voting system that integrates the best practices from prior research while addressing their limitations. Leveraging the Hyperion scheme as a foundation, we develop an enhanced protocol that not only guarantees everlasting privacy but also introduces everlasting receipt-freeness and coercion mitigation. Unlike existing systems like Selene and Hyperion, which rely on computational assumptions for privacy, our protocol offers privacy even against adversaries with unlimited computational power. In secure electronic voting systems with everlasting privacy, the focus is on futureproofing privacy, while sometimes election verifiability relies on the computational soundness of zero-knowledge proofs (ZKP), which are vulnerable to quantum adversaries. Therefore, a key technical challenge is designing e-voting systems with efficient post-quantum cryptographic primitives to secure both privacy and verifiability against quantum attacks. In this thesis, we advance the state of post-quantum ZKPs by focusing on the ZKPs proposed by Jain et al., which are based on the conservative Learning Parity with Noise (LPN) assumption. We optimize the efficiency of these ZKPs, achieve formal security verification using EasyCrypt, and uncover flaws in existing implementations, demonstrating their vulnerability to malicious provers. Additionally, we construct the first code-based ZKP of shuffle, enabling a verifiable and privacy-preserving e-voting protocol with mixing-based tallying. Our e-voting system ensures both verifiability and vote privacy through the computational difficulty of decoding random linear codes, marking it as the first verifiable code-based e-voting system.

M. Thanga Raj, Muthukumar Arunachalam

Ensuring the authenticity and integrity of digital images is increasingly critical as sophisticated manipulation techniques become more prevalent. This paper introduces an innovative approach utilizing adaptive zk-SNARKs (Zero-Knowledge Succinct Non-Interactive Arguments of Knowledge) to safeguard images against unauthorized alterations. Our method leverages zk-SNARKs to generate concise, privacy-preserving proofs that verify image authenticity, with parameters dynamically adjusted based on image content and context. We propose a dual-layered strategy: the first layer embeds cryptographic proofs into image metadata to provide robust yet compact verification, while the second layer features a real-time adaptive algorithm that optimizes zk-SNARKs parameters in response to detected manipulation patterns. Evaluated on the CASIA dataset, our approach achieves an accuracy rate of 98.7%, precision of 97.5%, recall of 99.0%, and an F-measure of 98.2% in detecting image tampering. Additionally, it maintains a PSNR of 47.2 dB, reflecting minimal impact on image quality. The proposed solution demonstrates significant robustness against various forgery techniques, positioning it as a substantial advancement in image security. This paper offers a comprehensive analysis of the method&s;s performance and its potential to enhance image security protocols through advanced cryptographic techniques.

Polyvios Damianakis

Electronic voting systems have long been proposed as a means of modernizing democratic participation by improving accessibility, reducing administrative costs, and accelerating electoral processes. Nevertheless, existing electronic voting architectures frequently rely upon centralized infrastructures that introduce significant challenges concerning transparency, security, auditability, and public trust. Blockchain technology has emerged as a promising alternative capable of addressing many of these limitations through decentralization, immutability, and distributed consensus. Despite considerable research activity, many proposed blockchain voting solutions remain conceptual, while relatively few studies present fully implemented and experimentally evaluated frameworks integrating multiple complementary security mechanisms.This study presents the design, implementation, and evaluation of a secure blockchain-based electronic voting framework built upon Hyperledger Fabric 2.4. The proposed architecture integrates smart contracts, distributed consensus mechanisms, AES-256 cryptographic vote protection, a conceptual zero-knowledge proof layer, and Merkle-tree-based integrity verification within a permissioned blockchain environment. A functional prototype was implemented in Go chaincode and deployed within a simulated regional election scenario representing the four prefectures of Crete, Greece.The study adopts a Design Science Research methodology and evaluates the proposed framework through a series of functional, security, and scalability experiments. The evaluation examined voter eligibility enforcement, duplicate vote prevention, ballot confidentiality, ledger integrity, auditability, and resistance against five distinct attack scenarios, including unauthorized ballot modification, ballot injection, and timestamp manipulation.The findings demonstrate that the proposed framework successfully preserves voter anonymity, prevents duplicate voting, detects unauthorized modifications in all tested scenarios, and enables transparent and independently verifiable election outcomes. While the results confirm the suitability of permissioned blockchain architectures for secure digital elections, several challenges remain, particularly regarding scalability, endpoint security, legal compliance, and large-scale deployment.Overall, this study contributes both a practical implementation and an empirical evaluation of a blockchain-enabled electoral infrastructure, providing insights into the future development of secure digital democratic systems.

T. Li, Liao, Taobo

We present a secure and efficient string-matching platform leveraging zk-SNARKs (Zero-Knowledge Succinct Non-Interactive Arguments of Knowledge) to address the challenge of detecting sensitive information leakage while preserving data privacy. Our solution enables organizations to verify whether private strings appear on public platforms without disclosing the strings themselves. To achieve computational efficiency, we integrate a sliding window technique with the Rabin-Karp algorithm and Rabin Fingerprint, enabling hash-based rolling comparisons to detect string matches. This approach significantly reduces time complexity compared to traditional character-by-character comparisons. We implement the proposed system using gnark, a high-performance zk-SNARK library, which generates succinct and verifiable proofs for privacy-preserving string matching. Experimental results demonstrate that our solution achieves strong privacy guarantees while maintaining computational efficiency and scalability. This work highlights the practical applications of zero-knowledge proofs in secure data verification and contributes a scalable method for privacy-preserving string matching.

A. L. Afzal

Federated Learning (FL) enables collaborative model training across hospitals while keeping patient data local, thus aiming to satisfy strict healthcare privacy regulations (e.g. HIPAA, GDPR). However, FL still leaks information via shared model updates, exposing it to membership inference and gradient inversion attacks. In this work, we propose an end-to-end framework that integrates zero-knowledge proofs (ZKPs) with FL to ensure both data privacy and trust in the aggregation process. In our design, each hospital (client) sends encrypted model updates to a central aggregator, which then computes the global model and simultaneously generates a succinct ZKP (e.g. a zk-SNARK) attesting to the correctness of the aggregation. Clients (or a verifier network) can efficiently verify this proof without learning any additional information. We simulate a disease-prediction task on synthetic medical data and evaluate metrics including predictive accuracy, proof generation/verification time, and communication overhead. Our results (see Table 1 and Fig. 3) show that incorporating ZKP maintains almost identical model accuracy compared to standard FL while adding moderate computational and bandwidth overhead. ZKP verification costs scale favorably (often <50% of proof generation time) and can be offloaded to a blockchain network to avoid burdening resource-constrained hospitals. The key contribution is a structured ZK-FL framework combining FL and zk-SNARKs, along with a formal threat model. This approach closes FL’s trust gap in healthcare settings, and suggests future work on scalable proof systems (e.g. post-quantum ZKPs) and integration with blockchain-based verifiers.

Marta Irene García Cid

The main motivation of this thesis is the uncertain panorama of cybersecurity risks and threats, accentuated by the arrival of the quantum computer. This type of computer is completely disruptive, since its operation is governed by quantum mechanical phenomena. The implementation of Shors algorithm in a quantum computer with relevant size and performance will allow breaking the security of the most currently used pre-quantum asymmetric algorithms. This panorama makes it necessary to research new cryptographic paradigms that are resistant to quantum threats. Thus, quantum and post-quantum cryptography emerge. Several national security agencies are recommending the immediate migration to quantum-resistant solutions of vulnerable critical cryptosystems, mainly by implementing post-quantum algorithms, some of them recently standardized. Quantum cryptography bases its security on the same physical foundations as quantum computers, being independent of the computational capacity of an adversary. The implementation of solutions based on quantum cryptography still requires greater technological maturity, development of standards and certification of devices. In addition, the infrastructures necessary for these networks are expensive and difficult to scale, in their current conception, due to the need to have trusted intermediate nodes. However, the rapid advances in this field allow to further research quantum communications networks to be a reality for daily operations where a high level of security is required. The main objective of this thesis is to investigate quantum cryptography-based solutions that go beyond quantum key distribution (QKD). The thesis has focused on proposing two novel cryptographic mechanisms ensuring that the new protocols are comparable in efficiency with pre-quantum and post-quantum algorithms. Furthermore, it has been taken into account that these protocols are implementable in current quantum communications infrastructures (QCI) to maximize the technical benefit of the investments carried out for these deployments. As a result, a quantum-assisted digital signature protocol (Q-DS) and a quantum zero-knowledge proof (QZKP) have been proposed, analyzed and implemented, which combine symmetric pre-quantum mechanisms with QKD. The proposed quantum-assisted digital signature protocol avoids the use of vulnerable pre- quantum public-key cryptosystems, using symmetric keys generated by QKD and using them with widely known NIST-approved hash functions, giving rise to a composite cryptosystem whose security against various attacks is demonstrated. For its part, the proposed quantum zero-knowledge proof allows the authentication of users in a QCI without revealing personal information during the process. The proposal of a quantum version of ZKP has been done in this thesis for the very first time, without precedent in the literature. A theoretical study as well as experimental tests have been carried out, resulting in a secure and efficient authentication mechanism. Finally, given the industrial nature of this thesis, the evolution of the political panorama regarding quantum technologies and PQC have been closely followed, including the positions of relevant security-oriented organizations and economic investments for project funding. These issues, although not technical, have influenced the design of the cryptographic protocols proposed in this thesis. RESUMEN La principal motivación de esta tesis es el panorama incierto de los riesgos y amenazas de ciberseguridad, acentuado por la llegada del ordenador cuántico. Este tipo de ordenadores son completamente disruptivos, ya que su funcionamiento se rige por fenómenos mecánico-cuánticos. La implementación del algoritmo de Shor en un ordenador cuántico con tamaño y rendimiento relevantes permitirá romper la seguridad de los algoritmos asimétricos pre-cuánticos más utilizados actualmente. Este panorama hace necesario investigar nuevos paradigmas criptográficos que sean resistentes a las amenazas cuánticas. Así, surgen la criptografía cuántica y post-cuántica. Varias agencias de seguridad nacional han recomendado la migración inmediata de los criptosistemas críticos vulnerables a soluciones "quantum-resistant", principalmente mediante la implementación de algoritmos post-cuánticos, algunos de ellos recientemente estandarizados. La criptografía cuántica basa su seguridad en los mismos fundamentos físicos que los ordenadores cuánticos, siendo independiente de la capacidad computacional de un adversario. La implementación de soluciones basadas en criptografía cuántica aún requiere de mayor madurez tecnológica, desarrollo de estándares y certificación de dispositivos. Además, las infraestructuras necesarias para estas redes son costosas y difíciles de escalar, en su concepción actual, debido a la necesidad de contar con nodos intermedios de confianza. Sin embargo, los rápidos avances en este campo permiten que la investigación de las redes de comunicaciones cuánticas se vaya convirtiendo en una realidad para las operaciones diarias donde se requiere un alto nivel de seguridad. El objetivo principal de esta tesis es investigar soluciones basadas en criptografía cuántica que vayan más allá de la distribución de claves cuánticas (QKD). La tesis se ha centrado en proponer dos mecanismos criptográficos novedosos asegurando que los nuevos protocolos sean comparables en eficiencia con algoritmos pre-cuánticos y post-cuánticos. Además, se ha tenido en cuenta que estos protocolos sean implementables en las actuales infraestructuras de comunicaciones cuánticas (QCI) para maximizar el beneficio técnico de las inversiones realizadas para estos despliegues. Como resultado, se han propuesto, analizado e implementado un protocolo de firma digital asistido por claves cuánticas (Q-DS) y una prueba de conocimiento cero cuántica (QZKP), que combinan mecanismos pre-cuánticos simétricos con QKD. El protocolo de firma digital cuántica propuesto evita el uso de criptosistemas de clave pública pre-cuánticos vulnerables, utilizando claves simétricas generadas por QKD y utilizándolas con funciones hash ampliamente conocidas aprobadas por el NIST, dando lugar a un criptosistema compuesto cuya seguridad frente a diversos ataques se demuestra. Por su parte, la QZKP propuesta permite la autenticación de usuarios en una QCI sin revelar información personal durante el proceso. La propuesta de una versión cuántica de ZKP se ha realizado en esta tesis por primera vez, sin precedentes en la literatura. Se ha realizado un estudio teórico así como pruebas experimentales, dando como resultado un mecanismo de autenticación seguro y eficiente. Finalmente, dada la naturaleza industrial de esta tesis, se ha seguido de cerca la evolución del panorama político en relación con las tecnologías cuánticas y PQC, incluyendo las posiciones de las organizaciones relevantes en materia de seguridad y las inversiones económicas para la financiación de proyectos. Estas cuestiones, aunque no técnicas, han influido en el diseño de los protocolos criptográficos propuestos en esta tesis.

Guoqiang Zhang, Qiwei Hu, Yu Zhang, Tao Jiang

The developing Sixth-Generation (6G) network aims to establish seamless global connectivity for billions of humans, machines, and devices. However, the rich digital service and explosive heterogeneous connection between various entities in 6G networks can not only induce increasing complications of digital identity management but also raise material concerns about the security and privacy of user identity. In this paper, we design a user-centric identity management that returns the sole control to the user self and achieves identity sovereignty towards 6G networks. Specifically, we propose a blockchain-based Identity Management (IDM) architecture for 6G networks, which provides a practical method to secure digital identity management. Subsequently, we develop a fully privacy-preserving identity attribute management scheme by using zero-knowledge proof to protect the privacy-sensitive identity attribute. In particular, the scheme achieves an identity attribute hiding and verification protocol to support users in obtaining and applying their identity attributes without revealing concrete data. Finally, we analyze the security of the proposed architecture and implement a prototype system to evaluate its performance. The result shows that our proposed architecture can ensure that users effectively manage their digital identity in 6G networks.

Junhui Zhao, Jingyan Chen, Longxia Liao, Qingmiao Zhang

The Internet of Autonomous Vehicles (IoAV) faces growing challenges in user privacy and communication security, stemming from dynamic network topologies induced by highspeed vehicle mobility, resource-constrained onboard devices, and the inherent tension between identity anonymity and traceability in latency-critical applications. Given the distributed architecture of fog computing and the limited storage and computational capabilities of vehicles, conventional anonymous authentication and centralized key negotiation mechanisms prove insufficient in addressing these issues. In response, We propose a distributed authentication and key negotiation protocol that combines multifactor biometrics, zero-knowledge proof (ZKP), and physical unclonable function (PUF) without relying on a trusted third party. Specifically, we design an efficient ZKP algorithm based on Chebyshev polynomials with low overhead and strong anonymity. Our key innovation is the implementation of independent key negotiation of three untrusted entities in a single protocol cycle, enabling 23 security features and functions. The performance analysis shows that the scheme takes only 17 ms to complete the protocol flow, and it reduces vehicle memory usage by 33% to 83%, service latency by 61% to 83%, and communication overhead by 12% to 50% compared to existing schemes.

S. M. Dilip Kumar, Namrta Tanwar, Namrta Tanwar, Aakarsh Chandna · 5 authors

The blockchain technology has disrupted the earlyage digital banking through concepts like bitcoin and ether [1,3].In this study, some major elements of the blockchain technology are examined-decentralized networks, smart contracts, cryptographic techniques, and consensus mechanisms of Proof of Work and Proof of Stake usage-and understanding how they contribute to safe, peer-to-peer transactions without intermediaries [2,5].Bitcoin can do no more than about seven transactions a second (TPS) is a very paltry competition of an impressive 30 to 40 TPS of Ethereum.This depicts the ongoing scalability challenges that need to be tackled by initiatives linked with Ethereum 2.0 and the Lightning Network [4,9].While most industries, apart from banking, have effectively made their blockchain applications and transparency useful-Supply Chain Management, Healthcare, and DeFi-currently poses challenges of transaction speed limitations, the vagueness of regulations, and energy consumption by mining [8].Emerging trends include Non-Fungible Tokens (NFTs), Central Bank Digital Currencies (CBDCs), and privacy enhanced through zero-knowledge proofs.There is hope for excellent feedback on the future of the blockchain from these and other initiatives yet to come into reality.

Yuliia Horbenko

Web Assembly (Wasm) and blockchain technology offer a viable solution for reliable and high-performance front-end systems. Wasm provides high execution speeds by incorporating code from high-level languages to improvise on performance limitations. Its sand-boxed execution model enhances security by extenuating memory-related weaknesses. Similarly, blockchain reinforces security with decentralized, tamper-resistant data structures and smart contracts. Conventional blockchain frameworks often suffer from computational overhead, but Wasm-based execution platforms like Polkadot and EOS optimize resource utilization and improve interoperability. This integration facilitates high-speed, reliable interactions in decentralized applications (dApps). Potential benefits include fast and secure off-chain computations, hence reducing blockchain congestion in front-end frameworks. However, challenges remain in securing Wasm execution in decentralized environments and optimizing blockchain and Wasm interoperability. A promising direction is to exploit Just-In-Time (JIT), Ahead-of-Time (AOT) compilation schemes along with zero-knowledge proofs to further enhance performance and security characteristics. By coupling Wasm’s efficiency with blockchain’s security, scalable and decentralized front-end systems are evolving to meet challenging web demand scenarios.

Sreena G. Nair, K. Rohini

Digital systems, networks, and data require robust cyber security measures to counter evolving cyber threats and unauthorized intrusions. Steganography enhances secure communication by embedding information within digital media such as images, audio, and video, rendering hidden messages nearly undetectable. However, traditional steganography suffers from vulnerabilities to steganalysis, limited data capacity, and exposure to statistical and machine learning-based attacks. To overcome these limitations, modern steganography systems integrate advanced cryptographic methods to enhance security and resilience. This review examines solutions combining the Advanced Encryption Standard (AES) for symmetric encryption, Rivest-Shamir- Adelman (RSA) for asymmetric encryption, Quantum Key Distribution (QKD) for secure key exchange, Elliptic Curve Digital Signature Algorithm (ECDSA) for lightweight authentication, and Zero-Knowledge Proof (ZKP) for privacy-preserving verification. These integrated techniques improve data confidentiality, prevent unauthorized access, and strengthen defences against steganalysis attacks. The study evaluates the performance, limitations, and prospects of these intelligent cybersecurity applications, highlighting their potential to advance secure data transmission in the digital landscape.

L V Vedashree, Yogesh Ramaswamy, Leeladhar Gudala, Haydeer MohamadAbbas · 5 authors

Nowadays, the increasing adoption of cloud computing has raised concerns about data privacy and security. However, the existing Homomorphic Encryption (HE) model has limited scalability which led to time-consuming in large-scale cloud computing environments. Hence, this research proposes Decentralized Blockchain-based Authentication with Zero-Knowledge Cloud Auditing (DBA-ZKCA) to improve data security and integrity in cloud computing environments. The proposed DBA-ZKCA consists of five key phases to ensure the privacy, authentication and secure data communication. The first phase initialization sets up cryptographic keys and identity verification parameters before cloud operations starts. These operations are executed by Cloud Service Providers (CSP) and Revocation Admin (RA) respectively. Then, cloud consumer registration phase allows only authorized users to access the cloud services. After that, authentication based on anonymous access phase utilizes DBA to store immutable authentication records. Next, the secure cloud communications phase with ZKCA where the Zero-Knowledge Proofs (ZKP) allow cloud users to verity data integrity without revealing actual data. Finally, revocation phase utilizes RA to revoke access for unauthorized users and updates authentication records for preventing future access. From the results, the proposed DBAZKCA achieved better results when compared to existing Federated Learning and Cryptography (FLC) in terms of accuracy (98.9%) respectively.

P. S. Joshi

In the current digital landscape, the demand for robust and layered security frameworks has intensified due to the increasing frequency and complexity of cyber threats. Cryptography and cybersecurity, though different in focus, are closely aligned and collectively form the core of modern digital defense strategies. Cryptography provides essential tools—such as encryption, hashing, and digital signatures—that safeguard the confidentiality, integrity, and authenticity of information. Cybersecurity builds on these techniques to implement policies and systems that protect against unauthorized access, data breaches, and malicious attacks. This paper examines the evolving connection between cryptography and cybersecurity, focusing on the development of cryptographic methods and their application in securing digital protocols like SSL/TLS, blockchain technologies, and public key infrastructures. Real-world use cases from healthcare, finance, and government are explored, highlighting the role of cryptographic integration in meeting regulatory standards like GDPR, HIPAA, and FISMA. The study also explores current challenges such as key management, scalability, and the threat posed by quantum computing. It further reviews emerging technologies including post-quantum cryptography, zero-knowledge proofs, and the integration of AI and machine learning for proactive, intelligent cybersecurity solutions.