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5,430 results · page 203 of 227
Maisha Afrida Tasnim, Abdullah Al Omar, Mohammad Shahriar Rahman, Md Zakirul Alam Bhuiyan
No abstract is available for this record.
Cheng Xu, Hongzhe Liu, Peifeng Li, Pengfei Wang
The vehicle to everything (V2X) requires the real-time integration of all kinds of information on roads, pedestrians, the environment, and vehicles themselves. This information also needs to be shared with other vehicles. The effective integration of information and the strong privacy protection are the key restrictions on the development of the V2X. The previous privacy protection model has mainly focused on the centralized network, and there were problems with the centralized gateway and single-point decision, which were not suitable for the decentralized scenario. Therefore, this paper proposes a remote attestation security model based on a privacy-preserving blockchain. The overall model involves two core steps. First, the vehicle provides the network with an evidence of a credible identity and integrity. Secured, the vehicles in the network calculate the nodes to make their respective decisions, and the accounting nodes summarize the sub-conclusions, form the final results, and write them into data blocks. The analysis shows that it possesses the security features of decentralization, traceability, anonymity, irreplaceability, and high efficiency. The model framework, core block chain structure, and protocol process are described in detail. The experimental results based on a realistic infrastructure are presented. These experimental results demonstrate that our scheme can effectively enhance the security of the communications of intelligent vehicles in the V2X.
Masayuki Abe, Charanjit S. Jutla, Miyako Ohkubo, Arnab Roy
We construct the first (almost) tightly-secure unbounded-simulation-sound quasi-adaptive non-interactive zero-knowledge arguments (USS-QA-NIZK) for linear-subspace languages with compact (number of group elements independent of the security parameter) common reference string (CRS) and compact proofs under standard assumptions in bilinear-pairings groups. In particular, under the SXDH assumption, the USS-QA-NIZK proof size is only seventeen group elements with a factor \(O(\log {Q})\) loss in security reduction to SXDH. The USS-QA-NIZK primitive has many applications, including structure-preserving signatures (SPS), CCA2-secure publicly-verifiable public-key encryption (PKE), which in turn have applications to CCA-anonymous group signatures, blind signatures and unbounded simulation-sound Groth-Sahai NIZK proofs. We show that the almost tight security of our USS-QA-NIZK translates into constructions of all of the above applications with (almost) tight-security to standard assumptions such as SXDH and, more generally, \(\mathcal{D}_k\)-MDDH. Thus, we get the first publicly-verifiable (almost) tightly-secure multi-user/multi-challenge CCA2-secure PKE with practical efficiency under standard bilinear assumptions. Our (almost) tight SPS construction is also improved in the signature size over previously known constructions.
Stephan Krenn, Thomas Lorünser, Anja Salzer, Christoph Striecks
No abstract is available for this record.
Ajay Kumar Shrestha, Julita Vassileva
No abstract is available for this record.
Chao Lin, Debiao He, Xinyi Huang, Muhammad Khurram Khan · 5 authors
Blockchain can potentially be deployed in a wide range of applications due to its capability to ensure decentralization, transparency, and immutability. In this paper, we design a cryptographic membership authentication scheme (i.e., authenticating graph data) to support blockchain-based identity management systems (BIMS). Such a system is designed to bind a digital identity object to its real-world entity. Specifically, we introduce a new transitively closed undirected graph authentication (TCUGA) scheme, which only needs to use node signatures (e.g., certificates for identifying nodes). The trapdoor hash function used in our scheme allows the signer to efficiently update the certificates without the need to re-sign the nodes. In other words, our scheme is efficient even though the graph dynamically adds or deletes vertices and edges. Moreover, our proposal can efficiently provide a proof when the edge between two vertices does not exist, thus solving the existing intractability issue in transitive signature (the main tool for authenticating graph data). Finally, we prove the security of our proposed TCUGA in the standard model and evaluate its performance to show its feasibility for BIMS.
Alexander Mense, Leandros Athanasiadis
The characteristics of the "blockchain" technology and especially its decentralized nature lead to the notion of neutrality, censorship resistance, and absolute truths, which makes the concept interesting for many different domains, such as finance, supply chain management, or the energy sector - of course also for the healthcare area (eHealth). Blockchains also offer the possibility for well-known access points for a distributed system with easy to use and simple to integrate programming interfaces, which makes it interesting as a central point for electronic healthcare data exchange in a distributed environment. This paper presents a concept for integrating and sharing distributed personal healthcare records based on smart contracts implemented on an Ethereum blockchain.
Ai Ishida, Yusuke Sakai, Keita Emura, Goichiro Hanaoka · 5 authors
No abstract is available for this record.
Luigi Castaldo, Vincenzo Cinque
On an EU level, the topic of electronic health data is a high priority. Many projects have been developed to realise a standard health data format to share information on a regional, national or EU level. All the projects favour and contribute to the development and improvement of the prerequisites for intra- and cross-border patient mobility. This work presents a new approach for the implementation of disruptive logging: an audit mechanism for cross-border exchange of eHealth data on OpenNCP, providing traceability and liability support within the OpenNCP infrastructure. Relevant parties could be legally obliged to keep a log of all privacy-critical operations performed by OpenNCP users.
Shlok Gilda, Maanav Mehrotra
Current methods for obtaining data consent from legal guardians are limited to paper forms and human data entry. While this classic method of granting consent is familiar to the parties involved, it involves little accountability or ongoing access oversight. Parents are asked to sign multiple permission forms, but are not given an efficient manner by which they can differentiate between fields for consent nor keep track of usage. Blockchain technology represents a promising approach for developing `smart contracts', digital promises to be executed without reliance upon a legal intermediary. Utilizing Hyperledger Fabric and Hyperledger Composer, we propose a framework of nested authorization, allowing a public school data administrator the ability to grant authorization rights to a third party afterschool intervention program and their volunteers, who meet with parents and obtain consent for data access rights relying on smart contracts. These data consent signatures allow researchers the ability to design targeted inventions, meeting the needs of the community.
Valeria Ferrari
No abstract is available for this record.
Faiza Loukil, Chirine Ghédira, Khouloud Boukadi, Aïcha Nabila Benharkat
No abstract is available for this record.
Noureddine Lasla, Mohamed Younis, Wassim Znaïdi, Dhafer Ben Arbia
Cooperative Intelligent Transportation System (C- ITS) enables inter-networking of vehicles for alerts exchanging in order to improve road safety. While this technology is about to enter the market in the upcoming years, critical questions related to the communication security continue to be challenging research concerns. Current solutions to secure inter-vehicle communication depend mainly on the use of digital certificates for authentication. However, such an approach imposes significant overhead on vehicles since it is computationally demanding and requires validation of the certificate within a limited period. In addition, relying on a central node for deciding on issuing and revoking certificates introduces a single point of failure and could even risk the safety of motorists. In this paper, we propose the use of Blockchain to keep track of the certificate of each vehicle (valid or revoked) in distributed and immutable records. In essence we replace certificate verification with a lightweight blockchain-based authentication approach. In addition, we propose a fully distributed vehicle admission/revocation scheme. We show that our scheme could alleviate the computation overhead and enhance the response time while improving the overall system security.
Ruinian Li, Yinhao Xiao, Cheng Zhang, Tianyi Song · 5 authors
Privacy in online applications has drawn tremendous attention in recent years. With the development of cloud-based applications, protecting users' privacy while guaranteeing the expected service from the server has become a significant issue. This paper surveyed the most popular cryptographic algorithms in privacy-preserving online applications to provide a tutorial-like introduction to researchers in this area. Specifically, this paper focuses on introduction to homomorphic encryption, secret sharing, secure multi-party computation and zero-knowledge proof.
Peter J. Ince, Joseph K. Liu, Peng Zhang
No abstract is available for this record.
Yinghui Zhang, Robert H. Deng, Jiangang Shu, Kan Yang · 5 authors
As a very attractive computing paradigm, cloud computing makes it possible for resource-constrained users to enjoy cost-effective and flexible resources of diversity. Considering the untrustworthiness of cloud servers and the data privacy of users, it is necessary to encrypt the data before outsourcing it to the cloud. However, the form of encrypted storage also poses a series of problems, such as: How can users search over the outsourced data? How to realize user-side verifiability of search results to resist malicious cloud servers? How to enable server-side verifiability of outsourced data to check malicious data owners? How to achieve payment fairness between the user and the cloud without introducing any third party? Towards addressing these challenging issues, in this paper, we introduce TKSE, a trustworthy keyword search scheme over encrypted data without any third party, trusted or not. In TKSE, the encrypted data index based on digital signature allows a user to search over the outsourced encrypted data and check whether the search result returned by the cloud fulfills the pre-specified search requirements. In particular, for the first time, TKSE realizes server-side verifiability which protects honest cloud servers from being framed by malicious data owners in the data storage phase. Furthermore, blockchain technologies and hash functions are used to enable payment fairness of search fees without introducing any third party even if the user or the cloud is malicious. Our security analysis and performance evaluation indicate that TKSE is secure and efficient and it is suitable for cloud computing.
Georg Fuchsbauer, Michele Orrù
While non-interactive zero-knowledge (NIZK) proofs require trusted parameters, Groth, Ostrovsky and Sahai constructed non-interactive witness-indistinguishable (NIWI) proofs without any setup; they called their scheme a non-interactive zap. More recently, Bellare, Fuchsbauer and Scafuro investigated the security of NIZK in the face of parameter subversion and observe that NI zaps provide subversion-resistant soundness and WI.
David Mendes, Irene Pimenta Rodrigues, César Fonseca, Manuel José Lopes · 6 authors
We introduce our solution developed for data privacy, and specifically for cognitive security that can be enforced and guaranteed using blockchain technology in SAAL (Smart Ambient Assisted Living) environments. Personal clinical and demographic information segments to various levels that assures that it can only be rebuilt at the interested and authorized parties and no profiling can be extracted from the blockchain itself. Using our proposal the access to a patient's clinical process resists tampering and ransomware attacks that have recently plagued the HIS (Hospital Information Systems) in various countries. The core of the blockchain model assures non-repudiation possible by any of the involved information producers thus maintaining ledger fidelity of the enclosed historical process information. One important side effect of this data infrastructure is that it can be accessed in open form, for research purposes for instance, since no individual re-identification or group profiling is possible by any means.
Zvika Brakerski, Nico Döttling
No abstract is available for this record.
Pavel Hubáček, Alon Rosen, Margarita Vald
We present an unconditional transformation from any honest-verifier statistical zero-knowledge (HVSZK) protocol to standard SZK that preserves round complexity and efficiency of both the verifier and the prover. This improves over currently known transformations, which either rely on some computational assumptions or introduce significant computational overhead. Our main conceptual contribution is the introduction of instance-dependent SZK proofs for NP, which serve as a building block in our transformation. Instance-dependent SZK for NP can be constructed unconditionally based on instance-dependent commitment schemes of Ong and Vadhan (TCC’08).
Yunru Zhang, Debiao He, Kim‐Kwang Raymond Choo
Internet of Things (IoT) and cloud computing are increasingly integrated, in the sense that data collected from IoT devices (generally with limited computational and storage resources) are being sent to the cloud for processing, etc., in order to inform decision making and facilitate other operational and business activities. However, the cloud may not be a fully trusted entity, like leaking user data or compromising user privacy. Thus, we propose a privacy‐preserving and user‐controlled data sharing architecture with fine‐grained access control, based on the blockchain model and attribute‐based cryptosystem. Also, the consensus algorithm in our system is the Byzantine fault tolerance mechanism, rather than Proof of Work.
Ben Berger, Zvika Brakerski
No abstract is available for this record.
Chaya Ganesh, Yashvanth Kondi, Arpita Patra, Pratik Sarkar
No abstract is available for this record.
Wang Yu-xiao, Juntao Gao
In Bitcoin financial system, a user’s privacy is supposed to be protected by means of anonymity. However, the anonymity makes illegal trades possible because nobody is able to reveal the real identities of the illegal users. In this paper, we propose a regulation scheme based on the ciphertext-policy hierarchical attribute-based encryption (CP-HABE). In the scheme, users’ identities are encrypted by using access policy and are contained in their transaction. A type of user is defined as the dependable regulation node, which is responsible for the regulation of transactions and encrypted identities. A new signature algorithm instead of the elliptic curve signature is adopted to generate wallet key pairs, this establishes a connection between wallet addresses and encrypted identities. When a transaction is doubted to involve illegal activities, the authorized regulation nodes are capable of revealing the users’ real identities and add the illegal identities to a public blacklist. Our system is based on a new CP-HABE scheme which is proved to be secure against chosen-plaintext attack in the standard model under the Bilinear Diffie–Hellman Exponent assumption. Finally, we give a performance analysis of our system. The proposed regulation system can reveal criminals’ identities undertaking illegal activities.