Blockchain Papers

Alessandro Chiesa, Marcel Dall’Agnol, Ziyi Guan, Nicholas Spooner · 5 authors

No abstract is available for this record.

Changrui Mu, Prashant Nalini Vasudevan

Abstract In an Instance-Hiding Interactive Proof (IHIP) (Beaver et al., in: Menezes and Vanstone (eds) Advances in cryptology—CRYPTO 1990, proceedings, lecture notes in computer science (including subseries lecture notes in artificial intelligence and lecture notes in bioinformatics), Springer, pp 326–338, 1990), an efficient verifier with a private input x interacts with an unbounded prover to determine whether x is contained in a language $$\mathcal {L}$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mi>L</mml:mi> </mml:math> . In addition to completeness and soundness, the instance-hiding property requires that the prover should not learn anything about x in the course of the interaction. Such proof systems capture natural privacy properties and may be seen as a generalization of the influential concept of randomized encodings (Ishai and Kushilevitz, in: Proceedings 41st annual symposium on foundations of computer science, pp 294–304, 2000; Applebaum et al., in: 45th annual IEEE symposium on foundations of computer science, pp 166–175, 2004; Agrawal et al., in: Halldórsson, Iwama, Kobayashi, Speckmann (eds) Automata, languages, and programming, Springer, Berlin, Heidelberg, pp 1–13, 2015) and as a counterpart to zero-knowledge proofs (Goldwasser et al., in: Symposium on the theory of computing, 1985). We investigate the properties and power of such instance-hiding proofs and show the following: Any language with an IHIP is contained in $${\mathsf {NP/poly}}\cap {\mathsf {coNP/poly}}$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:mrow> <mml:mi>NP</mml:mi> <mml:mo>/</mml:mo> <mml:mi>poly</mml:mi> </mml:mrow> <mml:mo>∩</mml:mo> <mml:mrow> <mml:mi>coNP</mml:mi> <mml:mo>/</mml:mo> <mml:mi>poly</mml:mi> </mml:mrow> </mml:mrow> </mml:math> . If an average-case hard language has a constant-round IHIP, then infinitely often non-uniform one-way functions exist. There is an oracle with respect to which there is a language that has an IHIP but not an SZK proof. IHIP’s are closed under composition with any efficiently computable function. We further study a stronger version of IHIP (that we call Simulatable IHIP) where the view of the honest prover can be efficiently simulated. For these, we obtain stronger versions of some of the above: Any language with a Simulatable IHIP is contained in $${\textsf{AM}}\cap {\textsf{coAM}}$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:mi>AM</mml:mi> <mml:mo>∩</mml:mo> <mml:mi>coAM</mml:mi> </mml:mrow> </mml:math> . If a worst-case hard language has a Simulatable IHIP, then explicit uniform one-way functions exist.

Jeyamohan Neera, Xiaomin Chen, Nauman Aslam, Biju Issac

Current mobile payment schemes gather detailed information about purchases customers make. This data can then be used to infer a customer’s spending behaviour, potentially violating their privacy. To tackle this problem, we propose an untraceable mobile payment scheme that strikes a better balance, preserving user privacy while allowing the Third-Party Service Provider (TPSP) to collect necessary information such as card details and transaction amount for regulatory compliance. Our scheme offers untraceability for legitimate users from malicious adversaries and curious TPSPs using cryptographic primitives such as partially blind signatures, zero-knowledge proofs, and identity-based signatures. It also guarantees that only authorised TPSPs can issue valid payment tokens, and even with limited data, the TPSP can still prevent dishonest customers/merchants from double-spending a payment token. We also propose a comprehensive evaluation framework to assess the untraceable payment schemes against seven key criteria such as untraceability, exculpability—merchant double-spending, exculpability—customer double-spending, unforgeability, confidentiality, message authenticity, efficiency, and regulatory compliance. We rigorously benchmark the security and privacy of our proposed payment scheme against this framework and other established schemes. Furthermore, we formally verify these properties using complexity-based analysis and Proverif modelling.

Jing Jiang, Xiaofeng Wang, Qianqian Xing, Jin Tang

Currently, personal information leakage and identity theft have become risks that cannot be ignored. As a robust authentication mechanism, multi-factor authentication (MFA) has gained prominence. However, many existing MFA schemes based on certificate-less public key cryptography amalgamate multiple authentication factors into a single factor for local verification, which fails to achieve independent authentication of each factor and is difficult to resist internal privilege attacks. To address these issues, this paper proposes a certificate-less multi-factor privacy authentication scheme based on elliptic curve cryptography. The proposed scheme divides the full private key into multiple authentication factors and employs the Schnorr zero-knowledge proof technique to independently generate challenge values for each factor, facilitating separate authentication of multiple factors. Notably, this approach eliminates the need to reconstruct the full private key during the authentication process, thereby effectively mitigating the risk of private key leakage.

B Yamini Supriya, B. Shubha, Meda Prajwal, C M Vikas · 8 authors

Abstract: The rise of blockchain technology and cryptography has transformed industries by enhancing security, transparency, and trust. This paper provides a comparative analysis of traditional systems and emerging solutions, focusing on the advances in blockchain and cryptography. Key innovations, challenges, and future trends are discussed. The review leverages research from multiple sources, offering a broad perspective on these fields.This paper explores the rapid advancements in blockchain technology and cryptography, comparing traditional systems with cutting-edge solutions. It highlights the evolution of consensus mechanisms, encryption methods, and their impact on scalability, security, and efficiency. By analyzing key innovations such as zero-knowledge proofs and homomorphic encryption, the study offers insights into overcoming existing limitations like high energy consumption and interoperability issues. The paper provides a comparative analysis of emerging solutions against conventional approaches, showcasing their potential to revolutionize industries. Finally, it outlines the challenges that must be addressed for mainstream adoption.

Justin A. Drake

The rapid evolution of Ethereum’s infrastructure calls for innovative mechanisms to enhance scalability, security, and performance. This paper introduces BeamSNARKS, a cutting-edge framework designed to address critical challenges in zero-knowledge proof systems. BeamSNARKS encompasses two groundbreaking innovations: the Dynamic zkSNARKS Generation Optimization Mechanism and the Dynamic SNARKification Technology. The former revolutionizes computational efficiency by dynamically retrieving state data relevant to proof generation, minimizing bandwidth and storage requirements while maintaining validation accuracy. The latter introduces adaptive circuit design and hierarchical proof aggregation to optimize transaction throughput and reduce the computational and financial overhead of Layer 1 submissions. Together, these innovations establish BeamSNARKS as a pivotal advancement in scalable, efficient, and resource-optimized zero-knowledge proof systems. Through comprehensive analysis and targeted experiments, this paper evaluates the performance of BeamSNARKS’s innovations, demonstrating their potential to transform Ethereum’s decentralized ecosystem and lay the groundwork for future high-throughput applications.

Baowei Wang, Fengxiao Guo, Yuting Liu, Bin Li · 5 authors

Abstract Voting plays a vital role in democratic societies. Adopting electronic voting can effectively increase voter participation and significantly reduce the financial burden on the organizers. In recent years, with the prevalence of blockchain technology, numerous blockchain-based electronic voting schemes have emerged. Compared with traditional electronic voting schemes, they have more favorable security features. However, existing schemes generally suffer from inefficient voting procedures, limited functionality, and dependence on specific blockchain platforms, making them challenging to deploy in diverse voting scenarios. This paper proposes an efficient and versatile electronic voting scheme on blockchain that addresses these problems using our proposed smart contract-based aggregated blind signature, zero-knowledge proofs, and threshold encryption scheme. In the paper, the scheme’s various features, including security, are analyzed in detail, and the scheme is deployed and tested on the Hyperledger Fabric and Ethereum blockchain platform. The experiment results demonstrate that the voting scheme satisfies the security requirement, and it has outstanding advantages in performance.

Janak Dhokrat, Namita Pulgam, Tabassum Maktum, Vanita Mane

In digital landscape of today’s ongoing world, the imperative for enhanced security in cloud-based data processing is paramount. This paper introduces an innovative framework that seamlessly integrates Homomorphic Encryption and Zero-Knowledge Proofs (ZKPs) to bolster data privacy and confidentiality. This paper explores the technical intricacies, real-world applications, and potential implications of this fusion framework. Homomorphic Encryption empowers computations on encrypted data without compromising privacy, while Zero-Knowledge Proofs offer a mechanism to verify computations without exposing sensitive details. The effectiveness and adaptability of the proposed framework is demonstrated through meticulous analysis and practical deployment in safeguarding cloud-based data processing. The proposed framework marks a significant stride towards creating an environment where data security is unequivocally prioritized.

Gogulakrishnan Thiyagarajan

No abstract is available for this record.

Valeh Farzaliyev, Calvin Pärn, Heleen Saarse, Jan Willemson

Abstract This paper studies several building blocks needed for electronic voting in order to prepare for the post-quantum era. In particular, we present lattice-based constructions for a generic zero-knowledge (ZK) proof of ballot correctness, a ZK proof of ballot correctness applicable for the homomorphic tallying scenario, and a ZK proof to achieve cast-as-intended verification during the vote casting period. We implement and benchmark our ballot correctness proofs, giving concrete estimations comparing the performance of homomorphic tallying and mix-net based e-voting systems in case of our lattice-based constructions.

O. Yu. Averkov, Alexandr Kuznetsov, I.V. Lysytska

Relevance: Starting with the invention of the Internet, the world began to change rapidly, and the pace of change is increasing, so the problem of data storage and processing is becoming more and more relevant. The ZK-STARK protocol is a new cryptographic zero-knowledge proof protocol that is not yet widely used in practice and allows you to check a message or a transaction on the blockchain network for authenticity without reproducing it completely. At the moment, gaps and problems related to this protocol are identified: computational complexity, possible poor compatibility with other protocols, and resistance to attacks from quantum computers. Therefore, the paper aims to supplement the coverage of the problem associated with computational complexity and to propose solutions to this problem. Purpose: on the basis of the theoretical implementation of the first stage named Arithmetization of the ZK-STARK protocol, to test its software implementation in order to provide recommendations on its most computationally efficient version. Research methods: mathematical statements on interpolation theory, group theory, number theory; information on Fibonacci numbers; information on the Euler function; generating element of a group; cyclic groups; Lagrange interpolation polynomial and the sequence of calculations of Arithmetization; Visual Studio 2022 programming environment, C++ programming language, NTL library, Microsoft Excel. Results of work: The result of the work is the theoretical implementation of the first stage of the ZK-STARK protocol and the effectiveness testing of the first stage, and providing recommendations for its most effective version. Conclusion: Testing has shown that the practical implementation of the Arithmetization based on the inverse fast Fourier transform has a time complexity , that is in times less than the time complexity of the Arithmetization based on inverse matrices method and Gaussian method for interpolation, that speeds up the work of Arithmetization of the ZK-STARK protocol.

Binbin Gu, Juncheng Fang, Faisal Nawab

In database applications involving sensitive data, the dual imperatives of data confidentiality and provable (verifiable) query processing are important. This paper introduces PoneglyphDB, a database system that leverages non-interactive zero-knowledge proofs (ZKP) to support both confidentiality and provability. Unlike traditional databases, PoneglyphDB enhances confidentiality by ensuring that raw data remains exclusively with the host, while also enabling verifying the correctness of query responses by providing proofs to clients. The main innovation in this paper is proposing efficient ZKP designs (called circuits) for basic operations in SQL query processing. These basic operation circuits are then combined to form ZKP circuits for larger, more complex queries. PoneglyphDB's circuits are carefully designed to be efficient by utilizing advances in cryptography such as PLONKish-based circuits, recursive proof composition techniques, and designing with low-order polynomial constraints. We demonstrate the performance of PoneglyphDB with the standard TPC-H benchmark. Our experimental results show that PoneglyphDB can efficiently achieve both confidentiality and provability, outperforming existing state-of-the-art ZKP methods.

Dimitris Mouris, Nektarios Georgios Tsoutsos

In crowd-sourced data aggregation over the Internet, participants share their data points with curators. However, a lack of strong privacy guarantees may discourage participation, which motivates the need for privacy-preserving aggregation protocols. Moreover, existing solutions remain limited with respect to public auditing without revealing the participants’ data. In realistic applications, however, there is an increasing need for public verifiability (i.e., verifying the protocol correctness) while preserving the privacy of the participants’ inputs, since the participants do not always trust the data curators. At the same time, while publicly distributed ledgers may provide public auditing, these schemes are not designed to protect sensitive information. In this work, we introduce two protocols, dubbed Masquerade and zk-Masquerade, for computing private statistics, such as sum, average, and histograms, without revealing anything about participants’ data. We propose a tailored multiplicative commitment scheme to ensure the integrity of data aggregations and publish all the participants’ commitments on a ledger to provide public verifiability. zk-Masquerade detects malicious participants who attempt to poison the aggregation results by adopting two zero-knowledge proof protocols that ensure the validity of shared data points before being aggregated and enable a broad range of numerical and categorical studies. In our experiments, we use homomorphic ciphertexts and commitments for a variable number of participants and evaluate the runtime and the communication cost of our protocols.

Tan Li, Samuel Cheng, Tak Lam Chan, Haibo Hu

Decentralized Federated Learning improves data privacy and eliminates single points of failure by removing reliance on centralized storage and model aggregation in distributed computing systems. Ensuring the integrity of computations during local model training is a significant challenge, especially before sharing gradient updates from each local client. Current methods for ensuring computation integrity often involve patching local models to implement cryptographic techniques, such as Zero-Knowledge Proofs. However, this approach becomes highly complex and sometimes impractical for large-scale models that use techniques such as random dropouts to improve training convergence. These random dropouts create non-deterministic behavior, making it challenging to verify model updates under deterministic protocols. We propose ProxyZKP, a novel framework combining Zero-Knowledge Proofs with polynomial proxy models to provide computation integrity in local training to address this issue. Each local node combines a private model for online deep learning applications and a proxy model that mediates decentralized model training by exchanging gradient updates. The multivariate polynomial nature of proxy models facilitates the application of Zero-Knowledge Proofs. These proofs verify the computation integrity of updates from each node without disclosing private data. Experimental results indicate that ProxyZKP significantly reduces computational load. Specifically, ProxyZKP achieves proof generation times that are 30-50% faster compared to established methods like zk-SNARKs and Bulletproofs. This improvement is largely due to the high parallelization potential of the univariate polynomial decomposition approach. Additionally, integrating Differential Privacy into the ProxyZKP framework reduces the risk of Gradient Inversion attacks by adding calibrated noise to the gradients, while maintaining competitive model accuracy. The results demonstrate that ProxyZKP is a scalable and efficient solution for ensuring training integrity in decentralized federated learning environments, particularly in scenarios with frequent model updates and the need for strong model scalability.

Ingrid Verbauwhede

Hardware security is the root of trust in all modern ICT (Information and Communications Technology) systems. However, hardware security means something different for different communities. It has also a very wide scope. It covers efficient, secure implementations of new generations of cryptography such as light-weight crypto, post-quantum crypto as well as advanced schemes such as zero-knowledge proofs, fully homomorphic encryption, and computing on encrypted data in general [1][2]. Yet, implementations also must resist a wide variety of side-channel, fault, and micro-architectural attacks. Post-quantum algorithms might resist the attacks developed for quantum computers. Yet, they also have to be resistant to these attacks on classic platforms, see e.g. [3]. Security protocols rely on more than only cryptographic algorithms. They require analog and digital circuit techniques to design quality true random number generators, physically unclonable functions, secure key storage, and many more [4]. A recent report on "Revitalizing the U.S. Semiconductor Ecosystem" (from Executive Office of the President, President's Council of Advisors on Science and Technology, September 2022) [5] describes a set of recommendations on semiconductors and system security. In this presentation, we will demonstrate how our research addresses these recommendations and we will illustrate this with recent results and ongoing projects.

Zhixin Ren, Yimin Yu, Enhua Yan, Taowei Chen

To enhance the security of ciphertext-policy attribute-based encryption (CP-ABE) and achieve fully distributed key generation (DKG), this paper proposes a ciphertext access control scheme integrating blockchain and off-chain computation with zero knowledge proof based on Layer-2 and multi-authority CP-ABE. Firstly, we enhance the system into two layers and construct a Layer-2 distributed key management service framework. This framework improves system efficiency and scalability while reducing costs. Secondly, we design the proof of trust contribution (PoTC) consensus algorithm to elect high-trust nodes responsible for DKG and implement an incentive mechanism for key computation through smart contract design. Finally, we design a non-interactive zero-knowledge proof protocol to achieve correctness verification of off-chain key computation. Security analysis and simulation experiments demonstrate that our scheme achieves high security while significantly improving system performance. The time consumption for data users to obtain attribute private keys is controlled at tens of milliseconds.

Hafiz Gulfam Ahmad Umar, Mariam Fareed, Sana Rubab, Romiza Rubab

A patient's medical record is an essential tool for treatment and care. However, questions about privacy, interoperability, and data fragmentation have been brought to light by conventional EHR systems. The research here employs blockchain technology to safeguard the transfer and storage of patient data. Since blockchain transactions may be recorded across several computers in a decentralized manner, any future data changes will need updating each subsequent block. The study makes use of tools such as Ganache, Truffle, Metamask, ZKPs, IPFS and RemixIDE. Blockchain validation is used for patient record retrieval; this procedure generates an encrypted Content ID and a decryption symmetric key. Further assurance of privacy and security is provided by the integration of Zero-Knowledge Proofs (ZKPs), which enable users to demonstrate record access privileges without disclosing sensitive information. In addition to boosting resilience and interoperability across systems, this decentralized strategy increases the confidentiality, integrity, transparency, and access management of healthcare data. The combination of blockchain technology with zero-knowledge proofs (ZKPs) increases the reliability of healthcare transactions by safely confirming data access between nodes.

Tom Gur, Jack O’Connor, Nicholas Spooner

We show that for every polynomial q* there exist polynomial-size, constant-query, non-adaptive PCPs for NP which are perfect zero knowledge against (adaptive) adversaries making at most q* queries to the proof. In addition, we construct exponential-size constant-query PCPs for NEXP with perfect zero knowledge against any polynomial-time adversary. This improves upon both a recent construction of perfect zero-knowledge PCPs for #P (STOC 2024) and the seminal work of Kilian, Petrank and Tardos (STOC 1997).

Jan Lauinger, Jens Ernstberger, Andreas Finkenzeller, Sebastian Steinhorst

Web users can gather data from secure endpoints and demonstrate the provenance of sensitive data to any third party by using privacy-preserving TLS oracles. In practice, privacy-preserving TLS oracles remain limited and cannot verify larger, sensitive data sets. In this work, we introduce new optimizations for TLS oracles, which enhance the efficiency of selectively verifying the provenance of confidential web data. The novelty of our work is a construction which secures an honest verifier zero-knowledge proof system in the asymmetric privacy setting while retaining security against malicious adversaries. Concerning TLS 1.3 in the one round-trip time (1-RTT) mode, we propose a new, optimized garble-then-prove paradigm in a security setting with malicious adversaries. Our improvements reach new performance benchmarks and facilitate a practical deployment of privacy-preserving TLS oracles in web browsers.

Cai, Dongliang, Borui Chen, Liang Zhang, Kexin Li · 5 authors

Attribute-Based Encryption (ABE) is a promising solution for access control in cloud services. However, the heavy decryption overhead hinders its widespread adoption. A general approach to address this issue is to outsource decryption to decryption cloud service(DCS). Existing schemes have utilized various methods to enable users to verify outsourced results; however, they lack an effective mechanism to achieve exemptibility which enables the honest DCS to escape from wrong claims. And it is impractical to assume that the DCS will provide free services. In this paper, we propose a blockchain-based payable outsourced decryption ABE scheme that achieves both verifiability and exemptibility without adding redundant information to ABE ciphertext. We use zero-knowledge proof to verify outsourced results on blockchain and introduce an optional single-round challenge game under optimistic assumption to address the high cost of proof generation. Moreover, our system achieves fairness and decentralized outsourcing to protect the interests of all parties. Finally, we implement and evaluate our scheme on Ethereum to demonstrate its feasibility and efficiency, the gas usage in attribute numbers from 5 to 60 is 11$\times$ to 140$\times$ in the happy case and 4$\times$ to 55$\times$ in the challenge case lower than the scheme of Ge et al. (TDSC'23).

Li Wei, Liang Peili, Li Fei

Abstract On‐chain sealed auctions represent a novel approach to electronic bidding auctions, wherein the introduction of zero‐knowledge proof technology has significantly enhanced the security of auctions. However, most mainstream on‐chain sealed auction schemes currently employ Bulletproofs to prove auction correctness, which leaves room for optimization in terms of verification time and inherent security. Addressing these issues, an on‐chain sealed auction scheme based on zero‐knowledge succinct non‐interactive argument of knowledge (zk‐STARK) is proposed. This scheme leverages the decentralization and immutability of blockchain and smart contracts to eliminate third‐party involvement while ensuring the security of the auction process. The Inter Planetary File System is utilized to provide a qualification review mechanism for the auctioneer, enabling the screening of unqualified bidders before the auction. Additionally, the scheme employs RSA encryption to conceal bidders' bids, Pedersen commitments to ensure the consistency of bidding information, and zk‐STARKs to verify the correctness of the winning bid. Security analysis and experimental results demonstrate that the proposed scheme meets the required security standards, with time consumption at various stages of the auction being within acceptable limits, and effectively reduces the time required for proof verification.

Sarah O'Donovan, Aisling Moran, Maria McDonagh, Lisa Ryan

The food industry is intertwined in every continent and culture, shaping dietary habits and economies worldwide (1) . Sustainability has become an increasingly important and widely discussed topic in the food industry influencing the decisions and actions of food industry companies and stakeholders worldwide. In an effort to become environmentally conscious and protect the earth for future generations, sustainability practices have been developed and integrated into food industry actions and policies which aim to meet present needs without compromising the ability of future generations to meet their own needs (2) . This study was part of a joint Erasmus KA2 European-funded project (2022-1-IE01-KA220-VET-000087508 Digitalisation of Sustainable Health Education) and aimed to explore current food sustainability priorities across the food industry in Europe and how initiatives are developed, implemented and evaluated to achieve food sustainability targets. In-depth semi-structured, audio-recorded interviews were conducted with 21 employees in the Food Industry sector across Ireland, Poland, Lithuania and Cyprus. These participants were selected based on their knowledge and oversight of their company’s sustainability practices. Interviews were transcribed and thematically analysed (3,4) , whereby the data were coded, themes identified and discussed by all authors. Three themes were identified in the data: 1. sustainable practice challenges, 2. factors for consideration, and 3. thinking to the future. Sustainable practices were already implemented in all but one of the 21 participating companies. The main drivers reported behind development of sustainable initiatives included complying to the Science-Based Targets initiative (SBTi) and setting emissions targets such as being net zero by 2050 and minimising waste generation. Participants reported cost, time required for monitoring and evaluation, retaining quality of products, and employee engagement as the main challenges for initiative development and implementation. When developing a sustainability initiative, participants felt that employee and stakeholder understanding and acceptance were important to consider for the success of the initiative. Future goals and initiatives were positively discussed as expanding on current priorities to reduce emissions and implement sustainable procurement and production practices, and gaps in research were identified as the proliferation of environmental labels and exploration of greater inter-collaboration between companies to share sustainability data. A focus on becoming more sustainable was at the centre of innovation development and future proofing for all participating companies, with plans to develop new or further enhance current policies to continue producing quality food in an environmentally sustainable way. Educating employees and stakeholders, including nutrition educators and graduates, on future initiatives and potential impacts is essential for raising awareness, strengthening implementation and ensuring long-term maintenance and success of food sustainability practices within industry. Future research into a policy for sharing of sustainability data, such as raw sustainability metrics between companies could strengthen initiative outcomes and inform nutrition education and research to meet market needs.

R. Kousalya, Gulshan Kumar

With the advancement of cutting-edge technologies, the Internet of Medical Things (IoMT) has assisted the healthcare sector by facilitating interaction between healthcare service providers and patients in remote areas. In IoMT, wearable or implantable sensors collect the patient’s record and share the information through a public network. Health-related information about the patient must be protected from a variety of attacks by the adversary since it is sensitive and extremely vulnerable to attacks. The sensor equipment that is implanted in the patient is also resource-constrained and has a low power capacity. The entities involved in the communication must be authenticated with one another in order to protect patients’ health information, anonymity, and reliability. While several authenticated key agreement protocols have been proposed, many suffer from high computational costs and storage cost, making them unsuitable for lightweight applications. This paper proposes a secure three-factor robust Elliptic Curve Cryptography (ECC) based mutually authenticated and key agreement protocol known as RELAKA for the IoMT environment, utilizing the benefits of one-way hash function. In proposed scheme, all entities, including the healthcare service providers and wearable sensors, are authenticated by the medical server. Subsequently, a secret key is established for each communication session and shared between all the entities. Additionally, mechanism for appropriate user revocation and re-registration is integrated to provide additional security in cases where a user’s QR code is tampered with by the attacker. The privacy of the proposed protocol is investigated by the potential use of zero knowledge proof. Furthermore, the efficacy of the authentication is examined by challenge and response mechanism. The informal security analysis demonstrates its resistance to threats such as DoS, impersonation, message modification, password guessing, and so on. The performance evaluation of RELAKA protocol indicates that the execution, communication, and storage costs is reduced by 87.59%, 43% and 60.71% respectively. Moreover, the outcomes of the AVISPA simulation illustrate that the RELAKA successfully evades both active and passive attacks. In addition, real-world testbed environment is developed with Raspberry pi 4 model B and the experimental results verifies the robustness of the proposed protocol. According to theoretical analysis and experimental evaluation, the RELAKA scheme is more secure and efficient than the existing protocols.

Mohammed El Baraka, Siham Ezzouak

This paper introduces a novel Distributed Key Generation (DKG) protocol based on the Commutative Supersingular Isogeny Diffie-Hellman (CSIDH) framework for secure multi-party cryptography. Our proposed protocol is designed to address scalability and security concerns, particularly in post-quantum cryptographic systems. The main contributions include the introduction of Piecewise Verifiable Proofs (PVPs) for non-interactive zero-knowledge verification of secret shares, and the provision of rigorous security analysis, including resistance to quantum adversaries via Shor’s and Grover’s algorithms. We analyze the protocol’s efficiency, ensuring low computational overhead even in large-scale systems, and compare it with other distributed cryptographic protocols such as RSA-based and lattice-based schemes. Through mathematical proofs and complexity analysis, we demonstrate that our protocol offers enhanced security, efficiency, and scalability in a post-quantum environment. The results presented in this paper provide a strong foundation for implementing secure multi-party computations in quantum-resistant systems.