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8,503 results · page 244 of 355
Chenkai Weng, Kang Yang, Jonathan Katz, Xiao Wang
No abstract is available for this record.
Oded Goldreich, Liav Teichner
We initiate a study of super-perfect zero-knowledge proof systems. Loosely speaking, these are proof systems for which the interaction can be perfectly simulated in strict probabilistic polynomial-time. In contrast, the standard definition of perfect zero-knowledge only requires that the interaction can be perfectly simulated by a strict probabilistic polynomial-time that is allowed to fail with probability at most one half. We show that two types of perfect zero-knowledge proof systems can be transformed into super-perfect ones. The first type includes the perfect zero-knowledge interactive proof system for Graph Isomorphism and other systems of the same form, including perfect zero-knowledge arguments for NP. The second type refers to perfect non-interactive zero-knowledge proof sys-tems. We also present a super-perfect non-interactive zero-knowledge proof system for the set
Yanhua Zhang, Ximeng Liu, Yifeng Yin, Qikun Zhang · 5 authors
No abstract is available for this record.
Yang Tao, Xi Wang, Rui Zhang
No abstract is available for this record.
Carsten Baum, Alex J. Malozemoff, Marc B. Rosen, Peter Schöll
No abstract is available for this record.
Emanuele Bellini, Philippe Gaborit, Alexandros Hasikos, Víctor Mateu
The advent of quantum computers is a threat to most currently deployed cryptographic primitives. Among these, zero-knowledge proofs play an important role, due to their numerous applications. The primitives and protocols presented in this work base their security on the difficulty of solving the Rank Syndrome Decoding (RSD) problem. This problem is believed to be hard even in the quantum model. We first present a perfectly binding commitment scheme. Using this scheme, we are able to build an interactive zero-knowledge proof to prove: the knowledge of a valid opening of a committed value, and that the valid openings of three committed values satisfy a given linear relation, and, more generally, any bitwise relation. With the above protocols it becomes possible to prove the relation of two committed values for an arbitrary circuit, with quasi-linear communication complexity and a soundness error of 2/3. To our knowledge, this is the first quantum resistant zero-knowledge protocol for arbitrary circuits based on the RSD problem. An important contribution of this work is the selection of a set of parameters, and an a full implementation, both for our proposal in the rank metric and for the original LPN based one by Jain et al. in the Hamming metric, from which we took the inspiration. Beside demonstrating the practicality of both constructions, we provide evidence of the convenience of rank metric, by reporting performance benchmarks and a detailed comparison.
Léo Robert, Daiki Miyahara, Pascal Lafourcade, Takaaki Mizuki
International audience
Elette Boyle, Niv Gilboa, Yuval Ishai, Ariel Nof
Secure computation protocols enable mutually distrusting parties to compute a function of their private inputs while revealing nothing but the output. Protocols with full security (also known as guaranteed output delivery) in particular protect against denial-of-service attacks, guaranteeing that honest parties receive a correct output. This feature can be realized in the presence of an honest majority, and significant research effort has gone toward attaining full security with good asymptotic and concrete efficiency.
Vadim Lyubashevsky, Ngoc Khanh Nguyen, Gregor Seiler
We present a novel lattice-based zero-knowledge proof system for showing that (arbitrary-sized) committed integers satisfy additive and multiplicative relationships. The proof sizes of our schemes are between two to three orders of magnitude smaller than in the lattice proof system of Libert et al. (CRYPTO 2018) for the same relations. Because the proof sizes of our protocols grow linearly in the integer length, our proofs will eventually be longer than those produced by quantum-safe succinct proof systems for general circuits (e.g. Ligero, Aurora, etc.). But for relations between reasonably-sized integers (e.g. $512$-bit), our proofs still result in the smallest zero-knowledge proof system based on a quantum-safe assumption. Of equal importance, the run-time of our proof system is at least an order of magnitude faster than any other quantum-safe scheme.
Emerson B. Tomaz, José Cláudio do Nascimento, Abdelhakim Hafid, José Neuman de Souza
The advent of miniaturized mobile devices with wireless communication capability and integrated with biosensors has revolutionized healthcare systems. The devices can be used by individuals as wearable accessories to collect health data regularly. This type of medical assistance supported by mobile devices to monitor patients and offer health services remotely is known as mobile health (mHealth). Although mHealth provides many benefits and has become popular, it can pose severe privacy risks. Many features in mHealth are managed through a smartphone. Thus, one of the most worrying issues involves communication between the monitoring devices and the smartphone. When communication uses Bluetooth, it is standard for a device to be paired with the smartphone; but generally, it is not exclusively associated with a specific mHealth app. This characteristic can allow a data theft attack by a malicious app or fake data injection by an illegitimate device. To address this issue, we present an authentication scheme based on Non-Interactive Zero-Knowledge Proof that is lightweight enough to run on mHealth devices with minimal resources. Our scheme ensures that legitimate devices interact exclusively with the official mHealth application. To ensure the patient's privacy-preserving throughout the system, we address the issues of storing, managing, and sharing data using blockchain. Since there is no privacy in the standard blockchain, we present a scheme in which the health data transmitted, stored, or shared are protected by Attribute-Based Encryption. The outcome is a system with fine-grained access control, entirely managed by the patient, and an end-to-end privacy guarantee.
Bhavye Sharma, Raju Halder, Jawar Singh
The development of a robust, transparent and interoperable E-healthcare infrastructure has been a difficult task due to many regulations and legislatures like HIPAA (Health Insurance Portability and Accountability Act) and GDPR (General Data Protection Regulation). Healthcare service providers prefer to store data about their patients in locked up silos, behind often inadequate layers of security and firewalls. Such an approach results in data breaches and limits the ability to get a holistic view of the medical history of a patient. The obscure cost of treatment is another issue brought to attention recently in media. In this paper, we have proposed a national blockchain framework for managing patients' Electronic Health Records (EHRs) access control and funds in the context of India's National healthcare scheme. We introduce a transparent insurance claim process for healthcare providers and an auditable trail of EHR access using smart contracts. We use a smart card approach allowing beneficiaries to authenticate their identity using zero-knowledge proofs and delegate access to service the providers via proxy re-encryption.
David Heath, Vladimir Kolesnikov
Zero-knowledge (ZK) proofs (ZKP) have received wide attention, focusing on non-interactivity, short proof size, and fast verification time. We focus on the fastest total proof time, in particular for large Boolean circuits. Under this metric, Garbled Circuit (GC)-based ZKP (Jawurek et al., [JKO], CCS 2013) remained the state-of-the-art technique due to the low-constant linear scaling of computing the garbling.
Wanxin Li, Hao Guo, Mark Nejad, Chien‐Chung Shen
Incorporation of connected vehicle (CV) data into real-time traffic management systems presents a host of new challenges resulting from the current lack of data integrity and data privacy in traffic networks. Over the past few years, blockchain technologies have been inspiring extensive innovations in the transportation field. However, due to the transparency property, sensitive data stored on the blockchain would be accessible to anyone, resulting in a lack of privacy. In this paper, we propose a decentralized and location-aware architecture to address the data integrity along with the privacy-preserving issues in blockchain-based traffic management systems. Our proposed architecture integrates with permissioned and modular blockchain network and non-interactive zero-knowledge range proof (ZKRP) protocol. We develop the prototype system on the Hyperledger Fabric platform and Hyperledger Ursa cryptographic library. The performance results show that our approach is effective and feasible for real-time traffic management while preserving the data privacy requirements.
Lasse Herskind, Panagiota Katsikouli, Nicola Dragoni
Our transaction history in the current centralized banking system has the ability to reveal a lot of private information for each spender, both to the banking system itself, but also to those entities that surround it (e.g., governments, industry etc). Examples of leaking information constitute the amounts spent, the goods on which the amounts were spent, the spending locations and the users we exchange money with. This knowledge is powerful in the hands of those who have it, and can be used in multiple ways, not always to our benefit. Cryptocurrencies, such as the famous Bitcoin, were proposed as a means to address the limitations of centralized banking systems and to offer its users privacy with regards to their transactional data. In this work, we perform a systematic literature review on the realm of privacy for electronic currencies. We present the development of digital money from electronic cash to cryptocurrencies and focus on the techniques that are employed to enhance user-privacy. Furthermore, we present flaws of the current cryptocurrency systems, which reduce the privacy of the cryptocurrency users. Finally, we describe three research directions to enhance privacy for cryptocurrencies: transaction propagation mechanisms, succinct ZK proof systems without a trusted setup, and specialised trustless zero-knowledge proofs.
Benedikt Bünz, Shashank Agrawal, Mahdi Zamani, Dan Boneh
No abstract is available for this record.
Mirko Zichichi, Stefano Ferretti, Gabriele D’Angelo
Data are becoming the cornerstone of many businesses and entire systems infrastructure. Intelligent Transportation Systems (ITS) are no different. The ability of intelligent vehicles and devices to acquire and share environmental measurements in the form of data is leading to the creation of smart services for the benefit of individuals. In this paper, we present a system architecture to promote the development of ITS using distributed ledgers and related technologies. Thanks to these, it becomes possible to create, store and share data generated by users through the sensors on their devices or vehicles, while on the move. We propose an architecture based on Distributed Ledger Technologies (DLTs) to offer features such as immutability, traceability and verifiability of data. IOTA, a promising DLT for IoT, is used together with Decentralized File Storages (DFSes) to store and certify data (and their related metadata) coming from vehicles or by the users' devices themselves (smartphones). Ethereum is then exploited as the smart contract platform that coordinates the data sharing through access control mechanisms. Privacy guarantees are provided by the usage of distributed key management systems and Zero Knowledge Proof. We provide experimental results of a testbed based on real traces, in order to understand if DLT and DFS technologies are ready to support complex services, such as those that pertain to ITS. Results clearly show that, while the viability of the proposal cannot be rejected, further work is needed on the responsiveness of DLT infrastructures.
Wenzheng Liu, Xiaofeng Wang, Wei Peng
Recently, application scenario of crowdsourcing IoT has covered to e-healthcare service, smart home, smart city, internet of vehicles due to the proliferation of smart devices such as smart mobile devices, smart wearable device, smart medical devices and smart furniture, etc. Patient's data collected by the smart devices send to the various remote medical servers. A group of medical professionals remote access patient data stored at the medical server database. Smart home users want to remote real-time access information of smart devices at home. All these operations need via wireless remote communication, which is suffering from various kinds of threat and attacks. Hence, there are a large number of multi-factor remote authentication and key agreement schemes designed for the application of crowdsourcing IoT. However, in most existing related multi-factor schemes, all factors for identity authentication only act as a parameter for encrypting the local secret key. In this paper, we propose a new secure remote multi-factor authentication scheme that includes three factors: 1) user identity; 2) password; and 3) user biometrics, which are authenticated by the remote server, act as a part of the secret key and participate in the key agreement process. We choose the chaotic map since it has a smaller key size and lower computational overhead, and then achieve remote multi-factor authentication and key agreement by artfully employ it to zero-knowledge technology and the fuzzy extractor technology. Our scheme is more secure and robust since the user revealing nothing sensitive information, and the adversary cannot impersonate any user even if he gets the server's master key. We have done security proof for our proposed scheme using the Random-Or-Real(ROR) model, Burrows-Abadi-Needham (BAN) logic, and ProVerif 2.00 to show that the presented scheme is secure. Also, we give an additional security analysis for other various attacks. Finally, according to the test and simulation result, the proposed scheme is very suitable for the power-constrained smart devices, and in the next generation 5G communication environment, its applicability and usability will be greatly enhanced.
Hongwei Shi, Shengling Wang, Qin Hu, Xiuzhen Cheng · 6 authors
The pool-hopping attack casts down the expected profits of both the mining pool and honest miners in Blockchain. The mainstream countermeasures, namely PPS (pay-per-share) and PPLNS (pay-per-last-N-share), can hedge pool hopping, but pose a risk to the pool as well as the cost to miners. In this study, we apply the zero-determinant (ZD) theory to design a novel pooled mining which offers an incentive mechanism for motivating non-memorial and memorial evolutionary miners not to switch in pools strategically. In short, our hopping-proof pooled mining has three unique features: 1) fee-free. No fee is charged if the miner does not hop. 2) wide applicability. It can be employed in both prepaid and postpaid mechanisms. 3) fairness. Even the pool can dominate the game with any miner, he has to cooperate when the miner does not hop among pools. The fairness of our scheme makes it have long-term sustainability. To the best of our knowledge, we are the first to propose a hopping-proof pooled mining with the above three natures simultaneously. Both theoretical and experimental analyses demonstrate the effectiveness of our scheme.
Ji-Yao Liu, Yunhua He, Chao Wang, Yan Hu · 6 authors
No abstract is available for this record.
Dexin Yang, Liming Liu
Proof of retrievability is a cryptographic tool which interacts between the data user and the server, and the server proves to the data user the integrity of data which he will download. It is a crucial problem in outsourcing storage such as cloud computing. In this paper, a novel scheme called the zero knowledge proof of retrievability is proposed, which combines proof of retrievability and zero knowledge proof. It has lower computation and communication complexity and higher security than the previous schemes.
Adrian Bejan
No abstract is available for this record.
Jeong Hoon Jo, Jong Hyuk Park
No abstract is available for this record.
Muhammad I.H. Sukmana, Marvin Petzolt, Kennedy A. Torkura, Hendrik Graupner · 6 authors
CloudRAID for Business (CfB) is a proof-of-concept enterprise cloud storage broker (ECSB) system that provides data security in the cloud. It applies a single-authority ciphertext-based policy attribute-based encryption (CP-ABE) scheme into its key management system (KMS) to solve its scalability and access control issues for multi-users and multi-devices scenarios. Unfortunately, this approach is not suitable for managing multiple companies as CfB customers since it could not provide secure and scalable zero-knowledge file sharing in the system. In this paper, we propose the practical implementation of a modified multi-authority attribute-based encryption (MA-ABE) scheme for CfB to provide a better secure and scalable KMS and zero-knowledge file sharing in a multi-company management scenario. Our work allows each company to have the authority to manage its attributes and keys for the company's employees as CfB users while CfB manages multiple companies without global decryption power to decrypt the company's encrypted data. Our evaluation shows that our proposal provides better performance with the smaller size of ciphertext and key, faster processing time, and better security compared with current CfB system.
Jonathan Myers, Leonardo Babun, Edward Yao, Sarah C. Helble · 5 authors
In the Internet of Things (IoT), applications hosted on resource-limited devices interact with the user and the physical world to provide digital connectivity and automation to daily activities, and frequently provide a point of entry into networks. However, many IoT applications are vulnerable to cyber attacks that can put networks, data, and connected devices at risk. Integrity measurement is an active defense technique used to detect malicious modification of software at runtime. While its usefulness has been well-demonstrated, integrity measurement is application-dependent and requires domain knowledge of the targeted software. Currently, adding integrity measurement to a platform requires substantial human effort, and thus application has been limited to usage on widely-deployed software such as the Linux kernel. Due to the diversity of IoT, vendors are unlikely to devote a substantial amount of effort to add integrity measurement systems to their devices. In this paper we introduce MAD- IOT (Memory Anomaly Detection for the Internet of Things), an integrity measurement framework for IoT. In order to provide low-cost integrity measurement agents and software anomaly detection for IoT platforms, MAD-IOT uses a process called IMAGE: Integrity Measurement Agent GEneration. The IMAGE process uses machine learning to automatically generate integrity measurement agents for arbitrary IoT devices. We demonstrated MAD-IOT and IMAGE on a proof-of-concept testbed and evaluated its performance with supervised and unsupervised machine learning models. Our results indicate that IMAGE is highly effective in recognizing known forms of misbehavior on IoT app operations, and very promising in identifying zero-day attacks. Finally, MAD-IOT introduces minimal overhead, making it feasible to implement on systems with very limited resources.