Follow blockchain research across journals, conferences, and preprint repositories.
5,430 results · page 194 of 227
Ron D. Rothblum, Adam Sealfon, Katerina Sotiraki
No abstract is available for this record.
Abdullah Al Omar, Rabeya Bosri, Mohammad Shahriar Rahman, Nasima Begum · 5 authors
No abstract is available for this record.
Denis Kirillov, Vladimir Korkhov, Vadim Petrunin, Mikhail Makarov · 6 authors
No abstract is available for this record.
Shangping Wang, Dan Zhang, Yaling Zhang
The sharing of personal health records can help to improve the accuracy of the doctor's diagnosis and to promote the progress of medical research. Currently, to reduce the maintenance cost of data, personal health records are usually outsourced to a third party such as the cloud service provider. In this case, patients may lose direct control over their personal health records and the semi-trusted cloud service provider may tamper with or reveal personal health records. Therefore, ensuring the privacy and integrity of personal health records and realizing the fine-grained access control are crucial issues when personal health records are shared. As a distributed architecture with decentralized and tamper-proof features, blockchain provides a new way to protect the personal health records sharing system. In this paper, we propose a new personal health records sharing scheme with data integrity verifiable based on blockchain. Aiming at the problems of privacy disclosure, limited keyword search ability and loss of control rights in the process of personal health record sharing, the new scheme uses searchable symmetric encryption and attribute-based encryption techniques to achieve privacy protection, keyword search, and fine-grained access control. Compared with the existing similar schemes, the new scheme allows patients to distribute attribute private key for users, avoiding many security problems caused by the existing of attribute authority in the scheme. Furthermore, the new scheme uses blockchain to manage keys in the scheme, avoiding the single point failure problem of centralized key management. In particular, the new scheme stores the hash values of encrypted personal health records in blockchain, and the related index set is stored in smart contract, which can further improve the efficiency of data integrity verification. Finally, performance evaluation and security analysis indicate that our scheme is secure and feasible for practical use.
Rupeng Yang, Man Ho Au, Zhenfei Zhang, Qiuliang Xu · 6 authors
No abstract is available for this record.
Benedict Faber, Georg Cappelen Michelet, Niklas Weidmann, Raghava Rao Mukkamala · 5 authors
Recent scandals on the abuse of personal information from social media platforms and numerous user identity data breaches raise concerns about technical, commercial, and ethical aspects of privacy and security of user data. European Union’s new General Data Protection Regulation (GDPR) is one of the largest changes in data privacy regulation and entails several key regulatory measures for both data controllers and data processors to empower and protect EU citizens’ privacy. In this research work, we propose a conceptual design and high-level architecture for a Blockchain-based Personal Data and Identity Management System (BPDIMS), a human-centric and GDPR-compliant personal data and identity management system based on the blockchain technology. We describe how BPDIMS’s architecture utilizes blockchain technology to provide a high-level of security, trust and transparency. We discuss how BPDIM’s human-centric approach with GDPR compliance shifts the control over personal data to the end users and empowers them better.
Kiran Adya, Samvid Dharanikota, B. Annappa
The keystone of information security has been access control. Very often, User data is misused and users are oblivious to the use of their data by unauthorized parties. Current strategies to provide storage for confidential data and subsequent authentication involve relying on a trusted third party for the same, which could be victims of Denial of Service (DoS) attacks or technical failures. This paper examines a strategy where the underlying framework for providing Access Control is the blockchain, hence decentralizing the mechanism of providing access control. Further in this paper, we demonstrate and model the User Data access on the Ethereum framework. Personal Information of the user by a website or an application is retrieved on a need-to-know basis from the off-blockchain, as determined by the user, the true owner of the data. Personal data is highly protected and the different permissions to different websites or applications are determined by the Smart Contract.
Ahmed Raza Rajput, Qianmu Li, Milad Taleby Ahvanooey, Isma Masood
Personal health records (PHRs) are private and vital assets for every patient. There have been introduced many works on various aspects of managing and organizing the PHR so far. However, there is an uncertain remaining issue for the role of PHR in emergencies. In a traditional emergency access system, the patient cannot give consent to emergency staff for accessing his/her PHR. Moreover, there is no secured record management of patient's PHR, which reveals highly confidential personal information, such as what happened, when, and who has access to such information. This paper proposes an emergency access control management system (EACMS) based on permissioned blockchain hyperledger fabric and hyperledger composer. In the proposed system, we defined some rules using the smart contracts for emergency condition and time duration for the emergency access PHR data items that patient can assign some limitations for controlling the PHR permissions. We analyzed the performance of our proposed framework by implementing it through the hyperledger composer based on the response time, privacy, security, and accessibility. The experiments confirm that our framework provides better efficiency compared with the traditional emergency access system.
Yanhua Zhang, Yifeng Yin, Ximeng Liu, Qikun Zhang · 5 authors
No abstract is available for this record.
Wei Ou, Mingwei Deng, Entao Luo
No abstract is available for this record.
Ronald Doku, Danda B. Rawat
Blockchain startups are basing their business models on disrupting the centralized way of data storage by highlighting the value of data to the public. A distributed approach to storing data is the safer way to prevent attacks is what is being evangelized. GAFA (Google, Apple, Facebook, Amazon) have monopolized data, therefore bringing in the most revenue whilst depriving the data generators of any form of compensation. In our work, we propose a platform where a user can store his/her own personal data. Here, we present to the user the right to decide what happens to their data. These decisions include selling, renting, and deleting data. The deletion of data undermines the fundamentals the blockchain is built on (data immutability). We address the issues of personal data sharing and how a user's right to delete his/her data can be enforced in a blockchain based network such as ours.
Kai Wang, Jiaqing Dong, Ying Wang, Hao Yin
Data is the input for various artificial intelligence (AI) algorithms to mine valuable features, yet data in Internet is scattered everywhere and controlled by different stakeholders who cannot believe in each other, and usage of the data in complex cyberspace is difficult to authorize or to validate. As a result, it is very difficult to enable data sharing in cyberspace for the real big data, as well as a real powerful AI. In this paper, we propose theSecNet, an architecture that can enable secure data storing, computing, and sharing in the large-scale Internet environment, aiming at a more secure cyberspace with real big data and thus enhanced AI with plenty of data source, by integrating three key components: 1) blockchain-based data sharing with ownership guarantee, which enables trusted data sharing in the large-scale environment to form real big data; 2) AI-based secure computing platform to produce more intelligent security rules, which helps to construct a more trusted cyberspace; 3) trusted value-exchange mechanism for purchasing security service, providing a way for participants to gain economic rewards when giving out their data or service, which promotes the data sharing and thus achieves better performance of AI. Moreover, we discuss the typical use scenario of SecNet as well as its potentially alternative way to deploy, as well as analyze its effectiveness from the aspect of network security and economic revenue.
Yanhua Zhang, Yupu Hu, Qikun Zhang, Huiwen Jia
No abstract is available for this record.
Antonio Arena, Pericle Perazzo, Gianluca Dini
Distributed ledgers allow us to replicate databases of records across mutually untrusted parties. The best known example of distributed ledger is perhaps the Bitcoin blockchain, which maintains a consistent history of financial transactions organized as a hashed chain of blocks. Distributed ledgers can be public, i.e., accessible by everyone, or private, i.e., accessible only by a given consortium of parties. In this paper, we explore the technological possibilities of applying Identity-Based Encryption and Attribute-Based Encryption to distributed ledgers. We introduce the novel concept of Virtual Private Ledger. A Virtual Private Ledger is a private distributed ledger embedded in a public cryptocurrency ledger by means of cryptography. A Virtual Private Ledger provides for the same confidentiality and integrity of a private distributed ledger, but without its high operational costs. In particular, nodes that maintain the ledger do not have to be always online to trust the order and the integrity of the records. We analytically show that Virtual Private Ledgers can be implemented over many existing cryptocurrency ledgers like Ethereum, EOS.IO, IOTA, XRP. Different cryptocurrencies lead to different trade-offs between the Virtual Private Ledger max record size, cost, validation time, and max consortium members.
Ze Wang, Jingqiang Lin, Quanwei Cai, Qiongxiao Wang · 6 authors
Traditional X.509 public key infrastructures (PKIs) depend on trusted certification authorities (CAs) to sign certificates, used in SSL/TLS to authenticate web servers and establish secure channels. However, recent security incidents indicate that CAs may (be compromised to) sign fraudulent certificates. In this article, we propose blockchain-based certificate transparency (CT) and revocation transparency (RT) to balance the absolute authority of CAs. Our scheme is compatible with X.509 PKIs but significantly reinforces the security guarantees of a certificate. The CA-signed certificates and their revocation status information of an SSL/TLS web server are published by the subject (i.e., the web server) as a transaction in the global certificate blockchain. The certificate blockchain acts as append-only public logs to monitor CAs’ certificate signing and revocation operations, and an SSL/TLS web server is granted with the cooperative control on its certificates. A browser compares the certificate received in SSL/TLS negotiations with the ones in the public certificate blockchain, and accepts it only if it is published and not revoked. We implement the prototype system with Firefox and Nginx, and the experimental results show that it introduces reasonable overheads.
Md. Mehedi Hassan Onik, Satyabrata Aich, Jinhong Yang, Chul‐Soo Kim · 5 authors
No abstract is available for this record.
Dong Zheng, Chunming Jing, Rui Guo, Shiyao Gao · 5 authors
The vehicular ad-hoc networks (VANETs) is one of the most promising application in the communications of smart vehicles and the smart transportation systems. However, authentication and privacy of users are still two vital issues in VANETs. It is crucial to prevent internal vehicles from broadcasting the forged messages while preserving the privacy of vehicles against the tracking attack. Moreover, in the traditional mode, the transactional data storage provides no distributed and decentralized security, so that the third party initiates the dishonest behaviors possibly. In this paper, based on blockchain technique, we propose a traceable and decentralized the Internet of Vehicle system framework for communication among smart vehicles by employing of a secure access authentication scheme between vehicles and RoadSide Units (RSUs). On the one hand, this scheme allows that vehicles employ pseudonyms for Vehicle to Vehicle (V2V) and Vehicle to Infrastructure (V2I) communications anonymously in the non-fully trusted environment. On the other hand, the transparency of vehicles in authentication and announcement is preformed efficiently by the blockchain technology. In addition, the transaction information is tamper-resistant that provides the distributed and decentralized property for the different cloud servers. With the help of Certificate Authority (CA) and the RoadSide Units (RSUs), our proposal achieves the conditional privacy to trace the real identity of the malicious vehicle in the anonymous announcements as well. Finally, through the theoretical analysis and simulations, our scheme is able to construct a secure and decentralized system framework of VANETs with accountability and privacy preservation.
ETH Zurich, Switzerland, Mathieu Chanson, Andreas Bogner, ETH Zurich, Switzerland · 8 authors
An ever growing variety of smart, connected Internet of Things (IoT) devices poses completely new challenges for businesses regarding security and privacy. In fact, the adoption of smart products may depend on the ability of organizations to offer systems that ensure adequate sensor data integrity while guaranteeing sufficient user privacy. In light of these challenges, previous research indicates that blockchain technology could be a promising means to mitigate issues of data security arising in the IoT. Building upon the existing body of knowledge, we propose a design theory, including requirements, design principles, and features, for a blockchain-based sensor data protection system (SDPS) that leverages data certification. To support this, we designed and developed an instantiation of an SDPS (CertifiCar) in three iterative cycles intented to prevent the fraudulent manipulation of car mileage data. Following the explication of our SDPS, we provide an ex post evaluation of our design theory considering CertifiCar and two additional use cases in the areas of pharmaceutical supply chains and energy microgrids. Our results suggest that the proposed design ensures the tamper-resistant gathering, processing, and exchange of IoT sensor data in a privacy-preserving, scalable, and efficient manner.
Vasavi Bande, Karu Prasada Rao, Sreenivas Mekala, T. Venkat Narayana Rao · 5 authors
A blockchain as a trustworthy and secure decentralized and distributed network has been emerged for many applications such as in banking, finance, insurance, healthcare and business. Recently, many communities in blockchain networks want to deploy machine learning models to get meaningful knowledge from geographically distributed large-scale data owned by each participant. To run a learning model without data centralization, distributed machine learning (DML) for blockchain networks has been studied. While several works have been proposed, privacy and security have not been sufficiently addressed, and as we show later, there are vulnerabilities in the architecture and limitations in terms of efficiency. In this paper, we propose a privacy-preserving DML model for a permissioned blockchain to resolve the privacy, security, and performance issues in a systematic way. We develop a differentially private stochastic gradient descent method and an error-based aggregation rule as core primitives. Our model can treat any type of differentially private learning algorithm where non-deterministic functions should be defined. The proposed error-based aggregation rule is effective to prevent attacks by an adversarial node that tries to deteriorate the accuracy of DML models. Our experiment results show that our proposed model provides stronger resilience against adversarial attacks than other aggregation rules under a differentially private scenario. Finally, we show that our proposed model has high usability because it has low computational complexity and low transaction latency.
Thomas Haines, Clémentine Gritti
No abstract is available for this record.
Elette Boyle, Niv Gilboa, Yuval Ishai, Ariel Nof
Secure multiparty computation enables a set of parties to securely carry out a joint computation on their private inputs without revealing anything but the output. A particularly motivated setting is that of three parties with a single corruption (hereafter denoted 3PC). This 3PC setting is particularly appealing for two main reasons: (1) it admits more efficient MPC protocols than in other standard settings; (2) it allows in principle to achieve full security (and fairness). Highly efficient protocols exist within this setting with security against a semi-honest</> adversary; however, a significant gap remains between these and protocols with stronger security against a malicious</> adversary. In this paper, we narrow this gap within concretely efficient protocols. More explicitly, we have the following contributions: Concretely Efficient Malicious 3PC. We present an optimized 3PC protocol for arithmetic circuits over rings with (amortized) communication of 1 ring element per multiplication gate per party, matching the best semi-honest protocols. The protocol applies also to Boolean circuits, significantly improving over previous protocols even for small circuits. Our protocol builds on recent techniques of Boneh et al. (Crypto 2019) for sublinear zero-knowledge proofs on distributed data, together with an efficient semi-honest protocol based on replicated secret sharing (Araki et al., CCS 2016). We present a concrete analysis of communication and computation costs, including several optimizations. For example, for 40-bit statistical security, and Boolean circuit with a million (nonlinear) gates, the overhead on top of the semi-honest protocol can involve less than 0.5KB of communication for the entire circuit,</> while the computational overhead is dominated by roughly 30 multiplications per gate in the field F247. In addition, we implemented and benchmarked the protocol for varied circuit sizes. Full Security. We augment the 3PC protocol to further provide full security</> (with guaranteed output delivery) while maintaining amortized 1 ring element communication per party per multiplication gate, and with hardly any impact on concrete efficiency. This is contrasted with the best previous 3PC protocols from the literature, which allow a corrupt party to mount a denial-of-service attack without being detected.
Dan Boneh, Elette Boyle, Henry Corrigan-Gibbs, Niv Gilboa · 5 authors
We introduce and study the notion of fully linear probabilistically checkable proof systems. In such a proof system, the verifier can make a small number of linear queries that apply jointly to the input and a proof vector.
Francesco Buccafurri, Lorenzo Musarella, Roberto Nardone
Web of Trust offers a way to bind identities with the corresponding public keys. It relies on a distributed architecture, where each user could play the role of certificate signer. With the widespread diffusion of social networks, the trust propagation is a matter of growing interest. This paper proposes an approach enabling the propagation in Web of Trust by means of Ethereum. The usage of Ethereum eliminates the necessity of single-organization trusted services, which is, in general, not realistic. Although the information stored on Ethereum is public, the privacy of users is protected because trust chains involve only Ethereum addresses and strong measures are implemented to contrast their malicious de-anonymization. The approach relies on the usage of a smart contract for storing the status of certificate signatures and to manage revocations. When a user u wants to trust another user v, the smart contract checks the presence of trust chains originating from root nodes of u.
Xiaohong Zhang, Xiaofeng Chen
A vehicular ad-hoc network (VANET) can improve the flow of traffic to facilitate intelligent transportation and to provide convenient information services, where the goal is to provide self-organizing data transmission capabilities for vehicles on the road to enable applications, such as assisted vehicle driving and safety warnings. VANETs are affected by issues such as identity validity and message reliability when vehicle nodes share data with other nodes. The method used to allow the vehicle nodes to upload sensor data to a trusted center for storage is susceptible to security risks, such as malicious tampering and data leakage. To address these security challenges, we propose a data security sharing and storage system based on the consortium blockchain (DSSCB). This digital signature technique based on the nature of bilinear pairing for elliptic curves is used to ensure the reliability and integrity when transmitting data to a node. The emerging consortium blockchain technology provides a decentralized, secure, and reliable database, which is maintained by the entire network node. In DSSCB, smart contracts are used to limit the triggering conditions for preselected nodes when transmitting and storing data and for allocating data coins to vehicles that participate in the contribution of data. The security analysis and performance evaluations demonstrated that our DSSCB solution is more secure and reliable in terms of data sharing and storage. Compared with the traditional blockchain system, the time required to confirm the data block was reduced by nearly six times and the transmission efficiency was improved by 83.33%.