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8,503 results · page 192 of 355
Jiahui Huang, Teng Huang, Jiehua Zhang
No abstract is available for this record.
Valerie Fetzer, Michael Klooß, Jörn Müller‐Quade, Markus Raiber · 5 authors
No abstract is available for this record.
Hoang Viet Anh Le, Quoc Duy Nam Nguyen, Thi Hong Tran, Tadashi Nakano
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.
Xiaohui Hu, Huiwen Jia, Jingang Liu, Zhi‐Qi Zhao
Identity-based cryptography (IBC) can be applied to scenarios that involve a large number of public keys in each execution. In this paper, we propose an efficient identity-based ring signature scheme on lattices with signature size logarithmic to the cardinality of the ring. To this end, we first construct an efficient identity-based ring identification scheme by combining preimage sampling algorithms and a zero-knowledge proof system for a tree-based accumulator. Then we apply the Fiat-Shamir transformation and obtain a secure identity-based ring signature scheme. We prove its security in the random oracle model under the small integer solution assumption.
Rishabh Bhadauria, Carmit Hazay, Muthuramakrishnan Venkitasubramaniam, Wenxuan Wu · 5 authors
No abstract is available for this record.
Minh-Chau Nguyen-Ngoc, Thao-Vinh Tran, Thu Nguyen, Khoa Tan Vo · 6 authors
No abstract is available for this record.
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.
Raza Ali Kazmi, Duc-Phong Le, Cyrus Minwalla
No abstract is available for this record.
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.
Long Ying, Yinyan Gong, Weihong Huang, Jiahong Cai · 6 authors
No abstract is available for this record.
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.
Teik Guan Tan, Vishal Sharma, Zeng Peng Li, Paweł Szałachowski · 5 authors
No abstract is available for this record.
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.
Kateryna Kuznetsova, Anton Yezhov, Oleksandr Kuznetsov, A. V. Tikhonov
No abstract is available for this record.
AoXuan Li, Gabriele D'Angelo, Su-Kit Tang, F. F. Fang · 5 authors
No abstract is available for this record.
Rajesh Kumar Dhanaraj, S. Suganyadevi, V. Seethalakshmi, Mariya Ouaissa
No abstract is available for this record.
Lei Xu, Y. Zhang, Liehuang Zhu
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.
Emanuele Giunta
No abstract is available for this record.
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.