Follow blockchain research across journals, conferences, and preprint repositories.
9,005 results · page 298 of 376
Carsten Baum, Huang Lin, Sabine Oechsner
No abstract is available for this record.
Ai Ishida, Yusuke Sakai, Keita Emura, Goichiro Hanaoka · 5 authors
No abstract is available for this record.
Xijuan Wu, Baodian Wei, Haibo Tian, Yusong Du · 5 authors
No abstract is available for this record.
Fan Zhang, Philip Daian, Iddo Bentov, Ari Juels
No abstract is available for this record.
Hayden Covington, Young B. Choi
Bitcoin and blockchain are two new and innovative technologies that may be confusing. This purpose of this paper is to differentiate these two new technologies and explain their functionalities. The concept of Bitcoin “mining” will be addressed, as well as the impact it has had on the hardware market. Finally, the benefits and concerns of implementing blockchain and Bitcoin will be provided. Despite the concerns, both blockchain and Bitcoin provide a plethora of possible new technological advanced, both in the terms of digital currencies as well as other avenues.
Wei Lu
No abstract is available for this record.
Moneeb Ahmed, Ihsan Elahi, Muhammad Abrar, Umair Aslam · 6 authors
In last decade, we have seen the emergence of various computer technologies, each of which was disrupting and revolutionary. Some of these technologies paved the way for a newer generation of technologies to make our lives easier. Some of these technologies are in the category of invention, as they change and disrupt the entire ecosystem. There was a big wave that produced a lot of new billionaires and millionaires. What was available for just 2 cents in 2009 is now available for more than $15,000 US. Yes, we are talking about Bitcoin and Blockchain. Blockchain is the technology behind Bitcoin. Cryptocurrency and especially Bitcoin have certainly divided the world into two zones—one that supports cryptocurrency and the other that opposes it. The use of cryptocurrency has been such a craze that there are around 1400+ cryptocurrencies like Bitcoin in the market, having more than 17+ million accounts. People have raised doubts about the future of Bitcoin. A few countries don’t allow cryptocurrencies in their economies, but almost all of them have provided tremendous support for Blockchain. Bitcoin is just one of the finest implementations of Blockchain, but Blockchain is certainly going to stay and is currently transforming the way we trust across work and business.
Fucai Luo, Kunpeng Wang
No abstract is available for this record.
Sharon Goldberg, Leonid Reyzin, Omar Sagga, Foteini Baldimtsi
In many applications, it is important to verify that an RSA public key (N; e) speci es a \npermutation over the entire space ZN, in order to prevent attacks due to adversarially-generated \npublic keys. We design and implement a simple and e cient noninteractive zero-knowledge \nprotocol (in the random oracle model) for this task. Applications concerned about adversarial \nkey generation can just append our proof to the RSA public key without any other modi cations \nto existing code or cryptographic libraries. Users need only perform a one-time veri cation of \nthe proof to ensure that raising to the power e is a permutation of the integers modulo N. For \ntypical parameter settings, the proof consists of nine integers modulo N; generating the proof \nand verifying it both require about nine modular exponentiations. \nWe extend our results beyond RSA keys and also provide e cient noninteractive zero- \nknowledge proofs for other properties of N, which can be used to certify that N is suitable \nfor the Paillier cryptosystem, is a product of two primes, or is a Blum integer. As compared to \nthe recent work of Auerbach and Poettering (PKC 2018), who provide two-message protocols for \nsimilar languages, our protocols are more e cient and do not require interaction, which enables \na broader class of applications.
Melissa Chase, Yevgeniy Dodis, Yuval Ishai, Daniel Kraschewski · 7 authors
We consider the problem of Non-Interactive Two-Party Secure Computation (NISC), where Rachel wishes to publish an encryption of her input x, in such a way that any other party, who holds an input y, can send her a single message which conveys to her the value f(x, y), and nothing more. We demand security against malicious parties. While such protocols are easy to construct using garbled circuits and general non-interactive zero-knowledge proofs, this approach inherently makes a non-black-box use of the underlying cryptographic primitives and is infeasible in practice.
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.
Joachim Zahnentferner
No abstract is available for this record.
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.
Rafail Ostrovsky, Giuseppe Persiano, Daniele Venturi, Ivan Visconti
No abstract is available for this record.
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.
Navid Alamati, Chris Peikert, Noah Stephens-Davidowitz
No abstract is available for this record.
Tuyet Duong
Cryptocurrencies like Bitcoin have proven to be a phenomenal success. The underlying techniques hold huge promise to change the future of financial transactions, and eventually the way people and companies compute, collaborate, and interact. At the same time, the current Bitcoin-like proof-of-work based blockchain systems are facing many challenges. In more detail, a huge amount of energy/electricity is needed for maintaining the Bitcoin blockchain. In addition, their security holds if the majority of the computing power is under the control of honest players. However, this assumption has been seriously challenged recently and Bitcoin-like systems will fail when this assumption is broken. This research proposes novel blockchain designs to address the challenges. We first propose a novel blockchain protocol, called 2-hop blockchain, by combining proof-of-work and proof-of-stake mechanisms. That said, even if the adversary controls more than 50% computing power, the honest players still have the chance to defend the blockchain via honest stake. Then we revise and implement the design to obtain a practical cryptocurrency system called Twinscoin. In more detail, we introduce a new strategy for difficulty adjustment in the hybrid blockchain and provide an analysis of it. We also show how to construct a light client for proof-of-stake cryptocurrencies and evaluate the proposal practically. We implement our new design. Our implementation uses a recent modular development framework for blockchains, called Scorex. It allows us to change only certain parts of an application leaving other codebase intact.
Chloé Hébant, Duong Hieu Phan, David Pointcheval
Since the seminal paper on Fully Homomorphic Encryption (FHE) by Gentry in 2009, a lot of work and improvements have been proposed, with an amazing number of possible applications. It allows outsourcing any kind of computations on encrypted data, and thus without leaking any information to the provider who performs the computations. This is quite useful for many sensitive data (finance, medical, etc.).
Mohsen Minaei, Pedro Moreno-Sánchez, Aniket Kate
No abstract is available for this record.
Bastien Buchwalter
No abstract is available for this record.
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).