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2,071 results · page 72 of 87
Yuzhe Tang, Zihao Xing, Cheng Xu, Chen Ju · 5 authors
No abstract is available for this record.
Jiwon Bang, Mi-Jung Choi
No abstract is available for this record.
Joseph A. Ricci, Ibrahim Baggili, Frank Breitinger
The current state of the art in digital forensics has primarily focused on the acquisition of data from cloud storage. Here, we present a new challenge in digital forensics: blockchain-based distributed cloud storage, using STORJ as a technology example.
Weihong Huang, Renfa Li, Jianbo Xu, Yin Huang · 5 authors
The rapid advancement in internet of things (IoTs) has created new demands for intellectual property (IP) protection. Existing zero-knowledge-based IP watermark detection schemes have low performance in real-time detection. To address this issue, we propose a position fuzzification-based IP watermark detection scheme mainly aiming to reduce the rounds of inquiry. Firstly, a random sequence is produced by chaos system to scramble all the resource positions of an IP design. Then watermark positions are fuzzified to make the scramble algorithm irreversible. A verifier can achieve zero-knowledge proof of IP ownership by one round of inquiry. Experiments show that the proposed scheme can greatly reduce computational complexity during blind IP watermark detection and enhance performance in real-time watermark detection.
Anupam Tiwari
No abstract is available for this record.
Shihong Zou, Jinwen Xi, Siyuan Wang, Yueming Lu · 5 authors
With the widespread popularity of Internet-enabled devices, mobile users can request and receive messages anytime and anywhere, which facilitates information feedback for smart city management. However, few people are willing to reflect or report some violations of law and discipline around them, and more people choose to ignore. In general, there are two major reasons for this phenomenon. First, reporting with a real name is highly recommended, but it is difficult to send trusted and reliable reporting messages without revealing the reporter's identity. Second, generally no benefit, users usually lack the motivation to report due to worrying about being retaliated. In this paper, we propose an effective anonymous reporting system called ReportCoin, a novel Blockchain-based incentive anonymous reporting system. ReportCoin guarantees user identity privacy and reporting message reliability throughout the reporting process. On the one hand, ReportCoin allows nondeterministic mobile users to vote the reporting by signing and to send anonymous announcements in the non-fully trusted network. On the other hand, ReportCoin motivates users with incentives to report without worrying about the disclosure of identity information to be retaliated. Meanwhile, account information and transaction records in ReportCoin are open, transparent, and tamper-resistant. The theoretical analysis and extensive experimental results show that ReportCoin is efficient and practical.
Nam Yong Lee, Jinhong Yang, Md. Mehedi Hassan Onik, Chul‐Soo Kim
The immutability of the blockchain technology facilitates it to establish a general consensus in a trustless environment, enabling a wide range of new applications, including distributed general-purpose data management and digital data sharing marketplace. This immutability, however, presents disadvantages for the blockchain technology, when it is used in other areas where the modification of data in blockchain is demanded. In this study, we propose a method for building modifiable blockchains in decentralized public network. To be specific, in computing the hash value of the block, the proposed method uses truncated hash values (these are called ‘target values’ in this paper) of the transactions that are modifiable upon future requests, instead of transactions themselves. By doing so, the proposed method provides an opportunity to modify those transactions by making truncated hash values of modified versions equal to their original target values. The proposed method uses several cryptographic techniques to prevent the modification of the transaction from being performed for malicious purposes, and a multichain structure to improve the efficiency in transaction modification. By accommodating the modification feature to the blockchain, proposed architecture complies to key demands of the data protection regulations such as ‘right to rectification’, ‘right to withdraw consent’, and ‘right to be forgotten’, et cetera. In addition, detailed threat analysis demonstrates that the proposed truncated hash-based modification is sufficiently secure to open up a wide range of new blockchain based services through added modifiability feature.
Marwa Chaieb, Souheib Yousfi, Pascal Lafourcade, Riadh Robbana
No abstract is available for this record.
Runnan Tan, Xiangyi Kong, Yu Zhang, Qingfeng Tan · 7 authors
No abstract is available for this record.
Harsh Jain, Rajvardhan Oak, Jay Bansal
Blockchain is one of the upcoming technologies in computing. It provides a tamper-proof distributed ledger which ensures integrity and authentication, as well as eliminates the need of a centralized trusted authority. This results in a secure and trusted system observed by the public. Although the blockchain was first applied to cryptocurrencies (which resulted in bitcoin), the features it provides are desirable for several other applications. In this paper, we develop a blockchain-based solution for securely digitizing the voting process. Election process is an important test of democracy and rigging the election may have disastrous consequences. Through our solution, we aim to provide a platform for voters to cast their vote securely online, from their home. The votes will be published in the blockchain, which will be observable by everyone. This would result in a tamper-proof ballot system which would be impossible to manipulate. The anonymity of voters will be maintained. We aim to apply this in the Indian context. We further show how our system meets the requirement of an online voting system, and how it resolves the issues present in current as well as proposed systems for the same.
Zeming Lu, Zoe L. Jiang, Yulin Wu, Xuan Wang · 5 authors
No abstract is available for this record.
Tsz Hon Yuen
No abstract is available for this record.
J. Vijayalakshmi, A. Murugan
No abstract is available for this record.
Satrajit Ghosh, Tobias Nilges
No abstract is available for this record.
GİZEM KIZILBEY
2008 yılında yayınlanan "Bitcoin: A Peer-to-Peer Electronic Cash System" adlı makale sayesinde bilgi sahibi olduğumuz Bitcoin, bilimsel litaratüre yeni terimler kazandırarak popülerliğini arttırmaktadır. Alternatif sanal para olarak geliştirilen Ethereum, merkezi bir sunucu veya bir kontrol noktaya ihtiyaç duymadan, karşılıklı uçlar arası anonim ve ucuz şekilde varlık transferine olanak sağlayan bir sistemdir. Blokzincir yapısının en yaygın kullanımı olan Bitcoin ve altcoinlerdir. Kripto paralar madencilik olarak adlandırılan ve zorlu bir algoritmanın çözümü ile gerçekleşmektedir. Sistemde yer alan herhangi bir madenci bu çözümü elde etmek için elinde bulunan ekran kartı ve işlemci gücünü kullanmaktadır. Bu çalışmada GPU'ların barındırdığı işlemcilerin, kayan noktalı işlem hesaplamalarında daha verimli olmaları sebebiyle Ethereum madenciliğinde kullanılan çeşitli ekran kartlarının performansları 4 kademeli bir iyileştirme paketi ile artırılarak karşılaştırılmıştır. Önerilen iyileştirme metotları için kullanılan ekran kartlarının model ve bellek miktarları şu şekildedir: 4 GB AMD R9 290, 4 GB AMD R9 380, 8 GB AMD R9 390, 4 GB AMD RX 560, 4 GB AMD RX 470, 4 GB AMD RX 480, 4 GB AMD RX 570, 4 GB AMD RX 580, 6 GB NVIDIA GTX1060, 8 GB NVIDIA GTX1070, 8 GB NVIDIA GTX1080. Bu çalışmanın en önemli amacı, Ethereum madenciliğine özgü Ethash özet algoritmasında iyileştirme yöntemleri uygulamaktır. Bu amaçla, AMD ve NVIDIA yonga seti grafik kartlarının daha düşük güç tüketimi ile daha hızlı algoritmalar çözmelerini sağlamak için iyileştirmeler yapılmıştır. Grafik kartları fabrika ayarlarıyla çalıştırıldığında, hiçbiri geçerli döviz kurlarından dolayı fayda getiremeyecek durumdadır. Algoritmanın hızını arttırmanın yanı sıra güç tüketimini azaltmak kar bölgesine geçiş için önemli bir faktör olmuştur. Yapılan çalışmalar sonucunda elde edilen değerlere bakıldığında yaklaşık % 30 performans artışı görülmüştür. Ayrıca iyileştirme paketi ile ekran kartlarının tükettiği elektrik enerjisi yüzde 20 ile yüzde 30 arası azaltılmıştır. Anahtar Kelimeler: Ethereum, Blokzincir, Kripto para madenciliği, GPU madenciliği
Ghada Almashaqbeh
Online content delivery has witnessed dramatic growth recently with traffic consuming over half of today’s Internet bandwidth. This escalating demand has motivated content publishers to move outside the traditional solutions of infrastructure-based content delivery networks (CDNs). Instead, many are employing peer-to-peer data transfers to reduce the service cost and avoid bandwidth over-provision to handle peak demands. Unfortunately, the open access work model of this paradigm, which allows anyone to join, introduces several design challenges related to security, efficiency, and peer availability. In this dissertation, we introduce CacheCash, a cryptocurrency-based decentralized content distribution network designed to address these challenges. CacheCash bypasses the centralized approach of CDN companies for one in which end users organically set up new caches in exchange for cryptocurrency tokens. Thus, it enables publishers to hire caches on an as-needed basis, without constraining these parties with long-term business commitments. To address the challenges encountered as the system evolved, we propose a number of protocols and techniques that represent basic building blocks of CacheCash’s design. First, motivated by the observation that conventional security assessment tools do not suit cryptocurrency-based systems, we propose ABC, a threat modeling framework capable of identifying attacker collusion and the new threat vectors that cryptocurrencies introduce. Second, we propose CAPnet, a defense mechanism against cache accounting attacks (i.e., a client pretends to be served allowing a colluding cache to collect rewards without doing any work). CAPnet features a bandwidth expenditure puzzle that clients must solve over the content before caches are given credit, which bounds the effectiveness of this collusion case. Third, to make it feasible to reward caches per data chunk served, we introduce MicroCash, a decentralized probabilistic micropayment scheme that reduces the overhead of processing these small payments. MicroCash implements several novel ideas that make micropayments more suitable for delay-sensitive applications, such as online content delivery. CacheCash combines the previous techniques to produce a novel service-payment exchange protocol that secures the content distribution process. This protocol utilizes gradual content disclosure and partial payment collection to encourage the honest collaborative work between participants. We present a detailed game theoretic analysis showing how to exploit rational financial incentives to address several security threats. This is in addition to various performance optimization mechanisms that promote system efficiency and scalability. Lastly, we evaluate system performance and show that modest machines can serve/retrieve content at a high bitrate with minimal overhead.
Karl Wüst, Kari Kostiainen, Vedran Čapkun, Srđjan Čapkun
No abstract is available for this record.
Rishabh Mehta, Naman Kapoor, Soumya Sourav, Rajeev Shorey
In this paper, we aim to address the major problem of correct image attribution for photos being uploaded on the stock photo websites and peer-to-peer image sharing marketplaces, ensuring that original photographers are rightfully recognized and credited for their works. There are now millions of royalty-free images being shared every week on stock photo websites. There is a major discontent among photographers and graphics designers who share images on such websites regarding a widespread malpractice where others try to take credit for and benefit from original author's work. This happens when someone other than the original author uploads the same image as one already shared on the marketplace or uses image processing methods such as rotation, cropping, gray scale conversion etc and then uploads this tampered image to avoid copyright violation detection. To counter such problems, we propose a decentralised peer-to-peer photo sharing marketplace built on top of Ethereum test chain and demonstrate how it is fair, trustworthy and practical. Our decentralised application leverages perceptual hashes and robust smart contracts of Ethereum to automatically detect and reject tampered images that are perceptually similar to images already present on the marketplace. Due to inherent properties of Blockchain, our marketplace has no central authority controlling it, no third party interference, no single point of failure, zero-censorship and preserves online user privacy. To the best of our knowledge, this is the first work that provides a practical solution for automatically detecting and rejecting perceptually similar images on a decentralised image sharing platform, thus protecting the copyrights of genuine image authors.
Ziyu Wang, Jianwei Liu, Zongyang Zhang, Yanting Zhang · 7 authors
No abstract is available for this record.
Lijuan Guo, Xuelian Li, Juntao Gao
No abstract is available for this record.
Riya Thakore, Rajkumar Vaghashiya, Chintan Patel, Nishant Doshi
Blockchain and Internet of Things (IoT), two of the top disruptive technologies, are already on their way of reshaping our future of the digital world, characterized by a drastic change in the current network architecture. Incorporation of IoT has brought the objects around us to life, making them ‘smart’ and capable of communicating with each other, thereby amassing massive data by constantly capturing the physical world, for analyzing and performing some intelligent action based on the same. It has made possible our dream of seamless integration of the digital and physical worlds, changing the very essence of our perception of the physical world. But, the problem with current IoT solutions is its need for a centralized party (like a cloud server), for connecting and communicating via the Internet, which poses a great threat to the privacy and security of the vast sensitive data being generated, whereas the original architecture design demands for a decentralized one like distributed or peer-to- peer (P2P) system. So, blockchain comes into play, providing a secure and trustworthy way of sharing information using a distributed/P2P model, to achieve transparency, security, privacy, auditability, resilience, access authentication, data immutability, etc. In this paper, we will look into how to combine both the technologies to overcome their shortcomings and obtain a greater gain from their benefits. We have presented a comprehensive survey on the basics of both the technologies, and the blockchain-based IoT (BIoT) architecture, protocols and functioning, and few examples BIoT applications that can be built on top of it, and comparison.
Yena Jeong, DongYeop Hwang, Ki‐Hyung Kim
In this paper, we propose a video surveillance system based on blockchain system. The proposed system consists of a blockchain network with trusted internal managers. The metadata of the video is recorded on the distributed ledger of the blockchain, thereby blocking the possibility of forgery of the data. The proposed architecture encrypts and stores the video, creates a license within the blockchain, and exports the video. Since the decryption key for the video is managed by the private DB of the blockchain, it is not leaked by the internal manager unauthorizedly. In addition, the internal administrator can manage and export videos safely by exporting the license generated in the blockchain to the DRM-applied video player.
Hai Wang, Yong Wang, Zigang Cao, Zhen Li · 5 authors
The blockchain, with its own characteristics, has received much attention at the beginning of its birth and been applied in many fields. At the same time, however, its security issues are exposed constantly and cyber attacks have caused significant losses in it. At present, there is little concern and research in the field of network security of the blockchain. This paper introduces the applications of blockchain in various fields, systematically analyzes the security of each layer of the blockchain and possible cyber attacks, expounds the challenges brought by the blockchain to network supervision, and summarizes research progress in the protection technology. This paper is a review of the current security of the blockchain and will effectively help the development and improvement of security technologies of the blockchain.
Jerinas Gresch, Bruno Rodrigues, Eder J. Scheid, Salil S. Kanhere · 5 authors
Diplomas have high importance in society since they serve as official proofs for education. Therefore, it is not surprising that forgeries of such documents have become commonplace. Thus, employers ordinarily have the diplomas manually verified by the issuer. Blockchain creates opportunities to overcome these obstacles, as it has revolutionized the way in which people interact with each other. Based on this, a holistic solution that includes issuance and verification of diplomas can be realized. This paper presents a proposal of a blockchain based system for managing diplomas called UZHBC (University of ZuricH BlockChain).