Follow blockchain research across journals, conferences, and preprint repositories.
8,503 results · page 211 of 355
Guanxiong Ha, Chunfu Jia, Xiaowei Ge, Jiawei Yuan · 6 authors
No abstract is available for this record.
R. Anusuya, D. Karthika Renuka, S. Ghanasiyaa, Karella Harshini · 6 authors
No abstract is available for this record.
Laasya Bangalore, Rishabh Bhadauria, Carmit Hazay, Muthuramakrishnan Venkitasubramaniam
No abstract is available for this record.
Chaya Ganesh, Hamidreza Khoshakhlagh, Markulf Kohlweiss, Anca Nitulescu · 5 authors
No abstract is available for this record.
Qinlong Huang, Chao Wang, Lixuan Chen
With the popularity of cloud computing services, an increasing number of users begin to use subscription-based services. Due to the semi-trusted cloud servers that may access the outsourced data, and malicious senders who may publish unauthorized data or junk data, access control encryption (ACE) schemes have been studied recently to enforce secure data write control as well as read control. However, their access control policies are specified by the authority or publishers, which do not apply to the subscriptions. In this paper, we propose DSFlow, a secure and fine-grained flow control system for subscription-based data services. DSFlow is designed in the cloud-edge computing architecture, which employs edge nodes to control the communications between publishers and cloud servers by sanitizing the original ciphertexts to resist malicious publishers, and allows any valid subscriber to decrypt the sanitized ciphertexts in cloud. We introduce a receiver-policy attribute-based ACE (RA-ACE) scheme for DSFlow, which embeds the fine-grained access control policy within the receiver's decryption key. We give a concrete construction of RA-ACE from key-policy attribute-based encryption, structure-preserving signature and non-interactive zero-knowledge proof, and formally prove the no-read rule and no-write rule of RA-ACE. The experiments demonstrate the efficiency of DSFlow compared with existing schemes.
Kristian Gjøsteen, Thomas Haines, Johannes Müller, Peter B. Rønne · 5 authors
No abstract is available for this record.
Nicolas Gailly, Mary Maller, Anca Nitulescu
No abstract is available for this record.
Giuseppe Persiano, Duong Hieu Phan, Moti Yung
No abstract is available for this record.
Léo Robert, Daiki Miyahara, Pascal Lafourcade, Takaaki Mizuki
No abstract is available for this record.
Anna Lysyanskaya, Leah Namisa Rosenbloom
No abstract is available for this record.
Léo Robert, Daiki Miyahara, Pascal Lafourcade, Takaaki Mizuki
No abstract is available for this record.
Damiano Abram, Ivan Damgård, Claudio Orlandi, Peter Schöll
No abstract is available for this record.
Kai Zhang, Zhe Jiang, Jianting Ning, Xinyi Huang
Secure cloud search service allows resource-constrained clients to effectively search over encrypted cloud storage. Towards enabling owner-enforced search authorization, the notion of attribute-based keyword search (ABKS) has been introduced and widely deployed in practice. To enhance traditional security of ABKS, two state-of-the-art solutions are presented to address keyword guessing attacks or setup inconsistency for secret key. Nevertheless, they have not simultaneously considered the following threats to a data user: (i) inconsistent secret key/cipher-index caused by outside dishonest authority and/or data owner; (ii) algorithm substitution attacks (ASA) launched by inside adversarial eavesdropping. These attacks may unfortunately lead to cloud data breach and user information exposure. To tackle such outside and inside threats, we introduce subversion-resistance and consistency for secure and fine-grained cloud document search services. In particular, we propose a consistent ABKS system with cryptographic reverse firewalls (CRF). Technically, we refer to verifiable functional encryption and employ non-interactive zero-knowledge proofs of discrete logarithm equality to ensure strong input consistency for ABKS. In addition, we build a trusted CRF zone for sanitizing algorithm outputs against ASA attacks. Moreover, we formalize the security model and formally prove security of our system. To clarify practical performance, we implement state-of-the-art solutions and our system in real cloud environment based on Enron dataset. The results show that our system achieves more enhanced security properties without obviously sacrificing performance. In particular, our system achieves comparable time and storage cost for document-index encryption and document search, as compared to state-of-the-art solutions.
Özgür Kesim, Christian Grothoff, Florian Dold, Martin Schanzenbach
No abstract is available for this record.
David Cerezo Sánchez
Optimal simple rules for the monetary policy of the first stochastically dominant crypto-currency are derived in a Dynamic Stochastic General Equilibrium (DSGE) model, in order to provide optimal responses to changes in inflation, output, and other sources of uncertainty. The optimal monetary policy stochastically dominates all the previous crypto-currencies, thus the efficient portfolio is to go long on the stochastically dominant crypto-currency: a strategy-proof arbitrage featuring a higher Omega ratio with higher expected returns, inducing an investment-efficient Nash equilibrium over the crypto-market. Zero-knowledge proofs of the monetary policy are committed on the blockchain: an implementation is provided.
Jonathan Heiss, Robert Muth, Frank Pallas, Stefan Tai
Many service systems rely on verifiable identity-related information of their users. Manipulation and unwanted exposure of this privacy-relevant information, however, must at the same time be prevented and avoided. Peer-to-peer blockchain-based decentralization with a smart contract-based execution model and verifiable off-chain computations leveraging zero-knowledge proofs promise to provide the basis for next-generation, non-disclosing credential management solutions. In this paper, we propose a novel credential on-chaining system that ensures blockchain-based transparency while preserving pseudonymity. We present a general model compliant to the W3C verifiable credential recommendation and demonstrate how it can be applied to solve existing problems that require computational identity-related attribute verification. Our zkSNARKs-based reference implementation and evaluation show that, compared to related approaches based on, e.g., CL-signatures, our approach provides significant performance advantages and more flexible proof mechanisms, underpinning our vision of increasingly decentralized, transparent, and trustworthy service systems.
Suthee Ruangwises, Toshiya Itoh
Shikaku is a pencil puzzle consisting of a rectangular grid, with some cells containing a number. The player has to partition the grid into rectangles such that each rectangle contains exactly one number equal to the area of that rectangle. In this paper, we propose two physical zero-knowledge proof protocols for Shikaku using a deck of playing cards, which allow a prover to physically show that he/she knows a solution of the puzzle without revealing it. Most importantly, in our second protocol we develop a general technique to physically verify a rectangle-shaped area with a certain size in a rectangular grid, which can be used to verify other problems with similar constraints.
Kaiqiang Huang, Luis Miralles-Pechuán, Susan Mckeever
No abstract is available for this record.
Binbin Tu, Min Zhang, Yu Chen
No abstract is available for this record.
Handong Zhang, Puwen Wei, Haiyang Xue, Yi Deng · 7 authors
No abstract is available for this record.
Surya Addanki, Kevin Garbe, Eli Jaffe, Rafail Ostrovsky · 5 authors
No abstract is available for this record.
Hamza Baniata, Attila Kertész
Trusted online credential management solutions are needed for instant and practical verification. Most of the available frameworks targeting this field violate the privacy of end-users or lack sufficient solutions in terms of security and Quality-of-Service (QoS). In this paper, we propose a Privacy-aware Fog-enhanced Blockchain-based online credential management solution, namely PriFoB. Our proposed solution adopts a public permissioned Blockchain model with different reliable encryption schemes, standardized Zero-Knowledge-Proofs (ZKPs) and Digital Signatures (DSs) within a Fog–Blockchain integrated framework, which is also GDPR compliant. We deploy both the Proof-of-Authority (PoA) and the Signatures-of-Work (SoW) consensus algorithms for efficient and secure handling of Verifiable Credentials (VCs) and global accreditation of VC issuers, respectively. Furthermore, we propose a novel three-dimensional DAG-based model of the Distributed Ledger (3DDL), and provide a ready-to-deploy PriFoB implementation. We discuss insights regarding the utilization and the potential of PriFoB, and evaluate it in terms of security, privacy, latency, throughput and power utilization. We analyze its performance in different layers of a Fog-enabled cloud architecture with simulation and emulation, and we show that PriFoB outperforms several Blockchain-based solutions utilizing Ethereum, Hyperledger Fabric, Hyperledger Besu and Hyperledger Indy platforms.
Kristian Gjøsteen, Mayank Raikwar, Shuang Wu
No abstract is available for this record.
Jayamine Alupotha, Xavier Boyen, Matthew McKague
Confidential Transactions (CT) hide coin amounts even from verifiers without the help of trusted third parties. Aggregable CTs are a scalable category of CTs with “spent coin record trimming”. For example, if Alice sends coins to Bob, who had sent similar coins to Charles, the aggregated transaction shows only that Alice sent coins to Charles by deleting Bob’s coin records. Since the number of spent coin records grows linearly with the number of transactions, faster than the number of accounts, cash systems based on aggregable CTs are highly scalable. However, existing quantum-safe aggregable CT protocols have large unspent coin records, and existing efficient aggregable CTs are vulnerable to quantum attacks. We introduce two aggregable CT protocols, based on new efficient homomorphic zero-knowledge proofs, from either the plain or Module Short Integer Solution (SIS and MSIS) problems, both believed to be secure against quantum adversaries. We further implement the MSIS-based aggregable CT protocol as a C library. Our experiments on 104transactions show that aggregation reduces the cash system’s size by 40%–54% when the output/input rate is in the range 1/1–2/1. For example, a cash system of 1.73 GB can be reduced to 0.98 GB when the output/input rate is 1.5, which has been the historical real-world average rate.