Blockchain Papers

Zeming Wei, Junlang Zhang, Shansi Ma, Yu Zhou · 9 authors

No abstract is available for this record.

Ощипок Олена-Іванна Василівна

Метою роботи є оптимізувати множення точок еліптичної кривої на скаляр за допомогою модернізованого метода “Подвійне скалярне множення з використанням трюку Штрауса-Шаміра з урахуванням Skew representation” та багато інших підходів. Ще однією метою роботи - зробити використання множення точок еліптичної кривої на скаляр безпечним в межах протоколу Zero-knowledge proof. З'ясувати, який метод множення буде найдешевшим в контексті визначеної метрики. Об’єктом дослідження є множення точок еліптичної кривої на скаляр в системі гаджет бібліотеках рекурсивних zk-Snark’s. Множення повинно виконуватися до стандартів протоколу Zero-knowledge proof. Також розглянуто варіанти практичного застосування описаних методів. У роботі виконане теоретичне та практичне дослідження, огляд алгоритмів та методів розв’язання задачі оптимізації з використанням різноманітних хитростей та підходів. Кодова база була написана мовою програмування Rust в бібліотеці franklin-crypto. Арифметизація, яка застосовується в бібліотеці – Plonkish та lookup table. Крива, яка була використана для тестування множення – Bn256. Ключові слова : точки еліптичної кривої, Zero-knowledge proof, мовою програмування Rust.

Lin You, Chunjie Guo, Gengran Hu

No abstract is available for this record.

David Pointcheval

Electronic voting is one of the most interesting application of modern cryptography, as it involves many innovative tools (such as homomorphic public-key encryption, non-interactive zero-knowledge proofs, and distributed cryptography) to guarantee several a priori contradictory security properties: the integrity of the tally and the privacy of the individual votes. While many efficient solutions exist for honest-but-curious voters, that follow the official procedure but try to learn more than just the public result, preventing attacks from malicious voters is much more complex: when voters may have incentive to send biased ballots, the privacy of the ballots is much harder to satisfy, whereas this is the crucial security property for electronic voting. We present a new technique to prove that an ElGamal ciphertext contains a message from a specific subset (quasi-adaptive NIZK of subset membership), using linearly-homomorphic signatures. The proofs are both quite efficient to generate, allowing the use of low-power devices to vote, and randomizable, which is important for the strong receipt-freeness property. They are well-suited to prevent vote-selling and replay attacks, which are the main threats against the privacy in electronic voting, with security proofs in the generic group model and the random oracle model.

JSC “KVANT-TELECOM”, Igor V. Martynenkov

The methods of eliminating vulnerabilities of zero-knowledge succinct non-interactive arguments of knowlede are considered. The methods are based on the security of public parameters formation in the form of common reference strings using a trusted third party and multilateral interaction. The multilateral formation of the common reference strings uses the only honest party with a fixed and unlimited set of participants, as well as verification of the reliability of the results. Examples of increasing the level of security of zero-knowledge succinct non-interactive arguments of knowledge based on the correction of proof verification equations and the values of the common reference strings, eliminating redundant elements from the common reference strings and the keys of proof formation are given. The protocols that develop the construction of the common reference strings from static to updatable and universal versions are mentioned.

B. Arulmozhi, J.I. Sheeba, S. Pradeep Devaneyan

The proposed research presents a blockchain-based healthcare system that seeks to address the limitations of current data-sharing methods by providing secure and efficient data transfer, enhancing data privacy and security, enabling effective data sharing interoperability, and promoting data-driven healthcare decision-making. A blockchain platform, IPFS, and rule-based access control are among the technologies suggested for use in the proposed system. Implementing this system could result in more personalized and effective medication for patients, as well as lower healthcare costs and improved care quality. The suggested approach, known as the Homomorphic Zero-Knowledge Blockchain Algorithm (HZBA), employs a block chain technique linked with Proxy Re Encryption with Homomorphic with Zero proof knowledge. Finally, the Covid19-dataset has collected from Kaggle repository and HCDNN method has used to complete the classification. The proposed blockchain-based healthcare system has the potential to revolutionize healthcare by resolving data privacy and security concerns, increasing data accuracy, fostering more interoperability in data sharing, and enhancing data-driven healthcare decision-making. The proposed blockchain-based healthcare system provides potential answers to data sharing difficulties in the healthcare business. One potential disadvantage is the system's complexity and cost of installation. The experimental results and classification performance parameters have been thoroughly demonstrated

Nima Sedaghat, Brianna Smart, J. Bryce Kalmbach, Erin L. Howard · 5 authors

We report a study exploring how the use of deep neural networks with astronomical Big Data may help us find and uncover new insights into underlying phenomena: through our experiments towards unsupervised knowledge extraction from astronomical Big Data we serendipitously found that deep convolutional autoencoders tend to reject telluric lines in stellar spectra. With further experiments we found that only when the spectra are in the barycentric frame does the network automatically identify the statistical independence between two components, stellar vs telluric, and rejects the latter. We exploit this finding and turn it into a proof-of-concept method for removal of the telluric lines from stellar spectra in a fully unsupervised fashion: we increase the inter-observation entropy of telluric absorption lines by imposing a random, virtual radial velocity to the observed spectrum. This technique results in a non-standard form of ``whitening'' in the atmospheric components of the spectrum, decorrelating them across multiple observations. We process more than 250,000 spectra from the High Accuracy Radial velocity Planetary Search (HARPS) and with qualitative and quantitative evaluations against a database of known telluric lines, show that most of the telluric lines are successfully rejected. Our approach, `Stellar Karaoke', has zero need for prior knowledge about parameters such as observation time, location, or the distribution of atmospheric molecules and processes each spectrum in milliseconds. We also train and test on Sloan Digital Sky Survey (SDSS) and see a significant performance drop due to the low resolution. We discuss directions for developing tools on top of the introduced method in the future.

Benedikt Bünz, Ben Fisch

No abstract is available for this record.

Yu Cao, Xuehui Du, Xiangyu Wu, Qiantao Yang · 6 authors

No abstract is available for this record.

Heba Elgabri, Mohamed Sameh Hassanein

The purpose of this article is to propose a framework named IoT-AC/Bc to secure smart cities. This article describes a new method that integrates Role-Based Access Control (RBAC) and Zero-Knowledge Proof (ZKP) models based on IoT and blockchain technologies. This method enables fast access authentication on smart city gates using ZKP, which provides an extra layer of security to address access control challenges. The framework consists of an Internet of Things Access Control-based Blockchain Smart Contract that manages user authentication, access session identities, and asset real-time interactions; and a Blockchain Ledger Management Smart Contract that implements distributed access control and tracks the ledger history of different activities. The framework achieves availability, scalability, multi-factor authentication, and decentralization, which strengthens distribution, role authority, access rights, and concurrent identity access requests. The results are demonstrated through a comparative analysis focused on the number of multithreaded requests, the cost of smart contract deployment, the multi-factor authentication performance for users’ interactions with the smart city gates, and the security strength levels. The framework’s performance effectiveness is evaluated through a case study that consists of various scenarios. The framework allows improving the security level by 94% under low and medium attack strength and 89% under high attack strength for 18 security attacks. This paper is novel because the framework uses ZKP over a blockchain network as an extra cryptographic technique with RBAC as a logical access control model to achieve fast accessibility authorization for users’ transactions while preserving their private identity on smart city gates. Keywords: Access Control, Blockchain, Internet of Things, Role-Based Access Control, Smart Cities, Multi-Factor Authentication DOI： https://doi.org/10.35741/issn.0258-2724.58.4.56

Valerie Fetzer, Michael Klooß, Jörn Müller‐Quade, Markus Raiber · 5 authors

No abstract is available for this record.

Egor Ermolaev, Iván Abellán Álvarez, Johannes Sedlmeir, Gilbert Fridgen

E-commerce has grown rapidly over the past years, with prevailing e-commerce platforms aggregating large amounts of customer data. This practice has several undesirable side effects, such as facilitating profiling that may lead to price discrimination and data feedback loops that can hamper competition. Moreover, data hoarding carries security risks through data breaches and undermines customers’ privacy expectations. On the other hand, convenience aspects and compliance regulation demand the processing and storage of user-related data. To address this tension field, we aim to conceptualize and iteratively refine a data-minimizinig e-commerce platform. Following a design science research approach, we identify design objectives and propose and implement a solution in which stakeholders receive only customer data that is indispensable for their part of the process. Our solution leverages digital identity wallets and general-purpose zero-knowledge proofs (zk-SNARKs). We aim to perform a criteria-based evaluation to assess our artifact’s feasibility and fitness from an interdisciplinary perspective. With our results, we hope to illustrate that combining state-of-the-art cryptographic techniques and an emerging digital identity paradigm allows reaching the user experience of incumbent e-commerce platforms while mitigating the undesirable socio-economic side effects of avoidable data disclosure.

Hongqing Liu, Chaoping Xing, Yanjiang Yang, Chen Yuan

No abstract is available for this record.

Gaurav Sarraf

The healthcare industry faces several security, privacy, and data integrity issues; blockchain technology provides a strong foundation to handle these issues. Traditional healthcare systems face issues such as unauthorized data access, breaches, and lack of interoperability across heterogeneous infrastructures. By leveraging decentralization, immutability, and consensus mechanisms, blockchain enables privacy-preserving data sharing and patient-centric identity management through Self-Sovereign Identity (SSI) frameworks. Cryptographic techniques such as Secure Multi-Party Computation (SMPC), Zero-Knowledge Proofs (ZKP), homomorphic encryption, commitment schemes, and many more provide the privacy of computation, the verification of consent, and the security of interactions among healthcare professionals, research institutions, and patients. Smart contracts further streamline automated processes, such as consent management, clinical trials, and electronic health record (EHR) transactions. Despite these advantages, challenges remain in scalability, key management, regulatory compliance, and usability. This review explores blockchain-based architectures, cryptographic methods, and privacy-preserving strategies, emphasizing their potential to strengthen trust, enhance security, and enable interoperable, efficient, and patient-centric healthcare systems while adhering to emerging global data protection standards.

Po-Chu Hsu, Atsuko Miyaji

An auction is commonly used to sell limited resources in modern society.M+ 1st-price auction sellsMidentical goods toBbidders. The topMwinners can buy the goods at theM+1st-price. Each bidder sends their bids secretly as a bit-slice bidding vector to a trusted manager. Bit-slice is commonly used to compare secret values without revealing them. However, the bit-slice bidding vector also limits the upper bound of a bid as the length of the bidding vector. A binary format bidding vector was proposed to increase the bid upper bound to an exponential scale. For example, given a bidding vector with length 32, a binary format bidding vector can increase the bid upper bound from 32 to 232. However, previous protocols that use binary format bidding vectors require a somewhat homomorphic encryption (SHE) and a trusted manager. To make sure no party except the bidder itself knows its bid, our protocol does not have any managers. Instead, each bidder interacts with the Smart Contract independently. We propose a zero-knowledge proof that allows our protocol only requires partially homomorphic encryption such as an ElGamal encryption. To our best knowledge, our protocol is the first secureM+ 1st-price auction protocol that can reach an exponential bid upper bound without a manager and SHE.

Fatemeh Heidari Soureshjani, Mathias Hall-Andersen, MohammadMahdi Jahanara, Jaimie Hoh Kam · 6 authors

Zero-knowledge proof systems are becoming increasingly prevalent and being widely used to secure decentralized financial systems and protect the privacy of users. Given the sensitivity of these applications, zero-knowledge proof systems are a natural target for formal verification methods. We describe methods for checking one such proof system: Halo2. We use abstract interpretation and an SMT solver to check various properties of Halo2 circuits. Using abstract interpretation, we can detect unused gates, unconstrained cells, and unused columns. Using an SMT solver, we can detect under-constrained circuits (in the sense that for the same public input they have two efficiently computable satisfying assignments). This is the first work we are aware of that applies lightweight formal methods to PLONKish arithmetization and Halo2 circuits.

Liqun Chen, Changyu Dong, Nada El Kassem, Christopher J. P. Newton · 5 authors

Direct Anonymous Attestation (DAA) was designed for the Trusted Platform Module (TPM) and versions using RSA and elliptic curve cryptography have been included in the TPM specifications and in ISO/IEC standards. These standardised DAA schemes have their security based on the factoring or discrete logarithm problems and are therefore insecure against quantum attackers. Research into quantum-resistant DAA has resulted in several lattice-based schemes. Now in this paper, we propose the first post-quantum DAA scheme from symmetric primitives. We make use of a hash-based signature scheme, which is a slight modification of SPHINCS+, as a DAA credential. A DAA signature, proving the possession of such a credential, is a multiparty computation-based non-interactive zero-knowledge proof. The security of our scheme is proved under the Universal Composability (UC) model. While maintaining all the security properties required for a DAA scheme, we try to make the TPM’s workload as low as possible. Our DAA scheme can handle a large group size (up to 2 60 group members), which meets the requirements of rapidly developing TPM applications.

Markulf Kohlweiss, Mahak Pancholi, Akira Takahashi

Most succinct arguments (SNARKs) are initially only proven knowledge sound (KS). We show that the commonly employed compilation strategy from polynomial interactive oracle proofs (PIOP) via polynomial commitments to knowledge sound SNARKS actually also achieves other desirable properties: weak unique response (WUR) and trapdoorless zero-knowledge (TLZK); and that together they imply simulation extractability (SIM-EXT). The factoring of SIM-EXT into KS + WUR + TLZK is becoming a cornerstone of the analysis of non-malleable SNARK systems. We show how to prove WUR and TLZK for PIOP compiled SNARKs under mild falsifiable assumptions on the polynomial commitment scheme. This means that the analysis of knowledge soundness from PIOP properties that inherently relies on non-falsifiable or idealized assumption such as the algebraic group model (AGM) or generic group model (GGM) need not be repeated. While the proof of WUR requires only mild assumptions on the PIOP, TLZK is a different matter. As perfectly hiding polynomial commitments sometimes come at a substantial performance premium, SNARK designers prefer to employ deterministic commitments with some leakage. This results in the need for a stronger zero-knowledge property for the PIOP. The modularity of our approach implies that any analysis improvements, e.g. in terms of tightness, credibility of the knowledge assumption and model of the KS analysis, or the precision of capturing real-world optimizations for TLZK also benefits the SIM-EXT guarantees.

AoXuan Li, Gabriele D'Angelo, Su-Kit Tang, F. F. Fang · 5 authors

No abstract is available for this record.

Alex Kemloh Kouyem

Diese Arbeit präsentiert ein Protokoll für vertrauliche Transaktionen auf Ethereum, das auf einer kontenbasierten Struktur und Paillier-Verschlüsselung basiert. Die Integration von Non-Interactive Zero-Knowledge Range Proofs (NIZKRP) verbessert die Sicherheit. Die Implementierung und Tests auf Ethereum zeigen vergleichbare Transaktionskosten (Sicherheitsparameter 40) im Vergleich zu Protokollen mit Bulletproofs. Bei einem Sicherheitsparameter von 128 (NIZKRP-Empfehlung) ist das Protokoll jedoch nicht anwendbar. Die Arbeit betont die Effizienz und Wettbewerbsfähigkeit, hebt jedoch die Herausforderung bei höheren Sicherheitsparametern hervor. Das Protokoll bildet eine solide Grundlage, erfordert jedoch weitere Optimierungen für breitere Anwendbarkeit.

Yu Tang, Yi Sun, Zhaowen Lin

No abstract is available for this record.

Maryam Sheikhi, Rosario Giustolisi, Carsten Schuermann

In 2016, Locher and Haenni (Locher andHaenni, 2016) proposed an e-voting scheme that offers verifiability, everlasting vote privacy, and computational receipt-freeness, as well as an informal discussion of how the scheme achieves such properties.We advance this line of work by proposing a new cryptographic scheme that provably satisfies those properties as well as everlasting participation privacy and efficient tallying.Receiptfreeness relies on deniable vote updating and verifiable null ballot posting, generated from public knowledge stored on the bulletin board.The everlasting vote and participation privacy properties directly result from the hash-based commitment scheme and efficient zero-knowledge proofs (SNARKs).Finally, we provide mathematical proofs for all the properties, including a new game-based definition of participation privacy.

Clémence Bouvier, Pierre Briaud, Pyrros Chaidos, Léo Perrin · 7 authors

No abstract is available for this record.

M. Zhang, Yu Chen, Chuanzhou Yao, Zhichao Wang

No abstract is available for this record.