Blockchain Papers

Clemens Brunner, Fabian Knirsch, Dominik Engel

No abstract is available for this record.

Luca Brunese, Francesco Mercaldo, Alfonso Reginelli, Antonella Santone

Blockchain technology is one of the most important and disruptive technologies in the world. Multiple industries are adopting the blockchain technology to innovate the way they work. One of the industries that are looking to adopt the blockchain is the healthcare industry. In fact, the protection of the private information stored in hospital database is a critical issue. In this paper we propose a method aimed to protect information exchanged in hospital networks, with particular regard to magnetic resonance images. As required from blockchain technology, each host network must validate the transiting data network: we exploit formal equivalence checking to perform this validation, by modeling magnetic resonance images in terms of automata by exploiting radiomic features.

Yuhong Li, Rahim Rahmani, Nicolas Fouassier, Peik Stenlund · 5 authors

Smart Grid represents an efficient power transmission, distribution and management system. However, solutions for Smart Grid have raised security and privacy problems. Moreover, with the introduction of renewable energy resources, such as rooftop solar panels and small biogas plants, more and more electricity consumers are involved in the energy generation system. This may cause the power system unstable and/or the waste of the energy. Blockchain is a promising technology for solving these problems in the future energy system on account of its distributed trust, anonymity, data integrity and availability. In this paper, we propose a Blockchain-based architecture for Smart Grid. By using the proposed architecture, electricity consumers can be fully involved in the energy system and tracing the details of the energy they have consumed or generated. At the same time, the stability of the energy system can be kept, reducing the waste of the energy and potential hazard to the electrical equipment.

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.

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.

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.

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.

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).

Ming Jin, Xiaojiao Chen, Sian-Jheng Lin

With the popularity of Bitcoin, there is a greater demand for the scalability of the Bitcoin blockchain, which is susceptible to the efficiency of block propagation. In the Bitcoin blockchain, efficient block propagation approach can reduce the computing power and the risk of forks. Meanwhile, larger blocks help to improve the throughput of transactions. Thus, the block propagation is a major issue of the scalability of the Bitcoin network. This paper introduces a method to reduce the required bandwidth of block propagation with erasure coding. To begin with, the network nodes are classified into several clusters. When a node wants to propagate a block, the node does not need to propagate the whole information of the block. Instead, the node can only transmit the transaction IDs and the coded information to each cluster. The simulation shows that the proposed method can significantly ease the network traffic among these clusters.

Xiaoliang Wang, Pengjie Zeng, Nick Patterson, Frank Jiang · 5 authors

Thanks to the rapid development in mobile vehicles and wireless technologies, the Internet of Vehicles (IoV) has become an attractive application that can provide a large number of mobile services for drivers. Vehicles can be informed of the mobile position, direction, speed, and other real-time information of nearby vehicles to avoid traffic jams and accidents. However, the environments of IoV could be dangerous in the absence of security protections. Due to the openness and self-organization of IoV, there are enormous malicious attackers. To guarantee the safety of mobile services, we propose an effective decentralized authentication mechanism for IoV on the basis of the consensus algorithm of blockchain technology. The simulation under the veins framework is carried out to verify the feasibility of the scheme in reducing the selfish behavior and malicious attacks in IoV.

Shangping Wang, Xixi Tang, Yaling Zhang, Juanjuan Chen

With the rapid development of electronic information technology, online transaction will gradually surpass traditional market transaction, among which online payment and asset delivery become the focus of attention. But in fact, due to the incomplete third-party payment mechanism and the intrusion risk of various charging Trojan, it is easy to cause a trust crisis. The existing centralized framework often leads to information asymmetry between the two parties. Therefore, how to realize the fairness of payment and the auditability of assets in the distributed system is a challenging problem. The emerging blockchain technology provides a new method with its openness, transparency and verifiability. Existing researches do not provide a complete shopping model for consumers, most of which focuses on payments or only on asset delivery. In this paper, we propose an auditable fair payment and physical asset delivery protocol based on smart contracts. Three types of smart contracts are designed to achieve reliable and fair payment among merchants, consumers and logistics companies. The traceability and auditability of blockchain provide an effective method to audit assets and data sharing in the whole transportation. In view of the phenomenon of goods being switched, the way of ”pre-verification” is added. In order to prevent the illegal elements to fake pickup code, induce consumers to conduct illegal operations, cause property loss, in our system the pickup codes are generated by consumers to reduce the risk of fraud. In addition, our plan designs a complete return process for the first time, providing better service experience and higher efficiency for consumers. Finally, all the contracts involved in the scheme are implemented and deployed on the ethereum test network. The results of security analysis and evaluation showed that our scheme was improved in cost, with high security and availability.

Till Neudecker, Hannes Hartenstein

No abstract is available for this record.

H Pranith, Manoj Kumar M V, H. A. Sanjay, Prashanth B S · 6 authors

No abstract is available for this record.

Yuna Jiang, Yi Zhong, Xiaohu Ge

The evolution of Industrial Internet of things (IIoT) boosts the amount of IIoT data. Machine learning promotes the progress of data analytics services. In order to facilitate the flow and explore the economic value of IIoT data, it is crucial to consider data packet transactions (DPTs) and data analytics service transactions (DASTs) simultaneously. Centralized data trading platforms emerge to realize transactions of data commodities. However, centralized platforms lack trust and robustness. How to realize DPTs and DASTs in a decentralized way is a challenging issue. In this paper, a new transaction solution based on the smart contract-enabled blockchain technology is proposed, which consists of the DPT smart contract and DAST smart contract. The DPT smart contract is implemented to trade data packets. The DAST smart contract provides a competitive way to trade data analytics services. Both smart contracts are designed to enable entities in IIoT to execute DPTs and DASTs automatically and honestly. Moreover, the transaction disputes between different IIoT entities are solved by the big data center off-chain, and the treatment results will be recorded on the blockchain by the big data center. The DPT smart contract and DAST smart contract are implemented and tested on Remix integrated development environment to achieve DPTs and DASTs. The gas costs of smart contracts are estimated and the security of the proposed solution is analyzed. The performance analysis demonstrates that the proposed solution is secure and feasible.

Kentaroh Toyoda, P. Takis Mathiopoulos, Tomoaki Ohtsuki

Bitcoin is one of the most popular decentralized cryptocurrencies to date. However, it has been widely reported that it can be used for investment scams, which are referred to as high yield investment programs (HYIP). Although from the security forensic point of view it is very important to identify the HYIP operators' Bitcoin addresses, so far in the open technical literature no systematic method which reliably collects and identifies such Bitcoin addresses has been proposed. In this paper, a novel methodology is introduced, which efficiently collects a large number of the HYIP operators' Bitcoin addresses and identifies them based upon a novel analysis of their transactions history. In particular, a scraping-based method is first proposed which is able to collect more than 2,000 HYIP operators' Bitcoin addresses from the Internet thus providing a large number of the HYIPs' samples. Second, a supervised machine learning technique, which classifies, whether or not, specific Bitcoin addresses belong to the HYIP operators, is introduced and its performance is evaluated. The proposed classification method is based upon two novel approaches, namely the rate conversion technique that mitigates the effect of Bitcoin price volatility and the sampling technique that reduces the computational amount without sacrificing the classification performance. By employing close to 30,000 real Bitcoin addresses, extensive performance evaluation results obtained by means of computer simulation experiments have shown that the proposed methodology achieves excellent performance, i.e., 95% of the HYIP addresses can be correctly classified, while maintaining a false positive rate less than 4.9%. In order to further validate the proposed classifier's ability to detect the HYIP operators' Bitcoin addresses, our designed classifier has been tested against a recently published list of the HYIP addresses maintaining its excellent detection accuracy by achieving a 93.75% success rate.

Sehyun Park, Seongwon Im, Youhwan Seol, Jeongyeup Paek

Bitcoin is a decentralized digital currency that has gained significant attention and growth in recent years. Unlike traditional currencies, Bitcoin does not rely on a centralized authority to control the supply, distribution, and verification of the validity of transactions. Instead, Bitcoin relies on a peer-to-peer (P2P) network of volunteers to distribute pending transactions and confirmed blocks, to verify transactions, and to collectively implement a replicated ledger that everyone agrees on. This P2P network is at the heart of Bitcoin and many other blockchain technologies. In this paper, we present a comparative measurement study of nodes in the Bitcoin network. We measure and analyze how many the so-called “volunteers” are in the Bitcoin P2P network by scanning the live Bitcoin network for 37 days in 2018 and compare them with the data reported by prior work in 2013~2016. This paper is motivated by the fact that Bitcoin has experienced explosive growth in terms of a number of users, transactions, value, and interest over a recent couple of years. Our investigation includes the IP addresses of Bitcoin nodes, size of the network, power law in the geographic distribution, protocol, and client versions, and network latencies and shows how today's network is different from early days. In addition, based on the observations made from the measurement study, we propose a simple distance-based peer selection rule for improved connectivity and faster data propagation. The evaluation results show that our proposed lightweight and backward-compatible peer selection rule has the potential to reduce data dissemination latency.

Haya R. Hasan, Khaled Salah

With the rise of artificial intelligence (AI) and deep learning techniques, fake digital contents have proliferated in recent years. Fake footage, images, audios, and videos (known as deepfakes) can be a scary and dangerous phenomenon and can have the potential of altering the truth and eroding trust by giving false reality. Proof of authenticity (PoA) of digital media is critical to help eradicate the epidemic of forged content. Current solutions lack the ability to provide history tracking and provenance of digital media. In this paper, we provide a solution and a general framework using Ethereum smart contracts to trace and track the provenance and history of digital content to its original source even if the digital content is copied multiple times. The smart contract utilizes the hashes of the interplanetary file system (IPFS) used to store digital content and its metadata. Our solution focuses on video content, but the solution framework provided in this paper is generic enough and can be applied to any other form of digital content. Our solution relies on the principle that if the content can be credibly traced to a trusted or reputable source, the content can then be real and authentic. The full code of the smart contract has been made publicly available at Github.

Jesús Máximo Montes Díaz, Víctor M. Larios, Manuel Avalos, Cecilia E. Ramírez

Nowadays, performance and promptness in the production line are significantly relevant; solutions are being delivered each quarter lead by the evolving innovation of technology which is moving at a fast paste. Taking into consideration concepts from Smarter Cities, Smart Contracts, and Blockchain, we will include these tools in the daily operations of International Business Machines' supply chain to reduce these transaction times radically, implementing agile practices. Fundamentally using IBM Bluemix, which is a fast-growing Platform that provides support for development organizations by defining various users and roles in the cloud environment. IBM Bluemix provides an extensive inventory of runtime and services that enterprises and developers can use in cloud applications without requiring significant development effort. We as developers can quickly build applications with a choice of several runtimes as can be needed in Supply Chain operations. Furthermore, as the workloads increase, applications can promptly scale ondemand to add more memory or processing power to ensure an optimal block chain experience application. Supply Chain operations can now shift their client-side code into a cloud system environment to leverage service integration, internal confidential activities and services, cloud data and the infrastructure capabilities. It will allow operations to be more productive and highly available and flexible, achieving efficient and sustainable development based on the analysis of real-time information shared by stakeholders and connected devices in a Smart City Environment. IBM is seen as a leader in blockchain, from recent surveys it is revealed that IBM is leading the way of blockchain technology, with more than 40% of respondents raking it number one. International customers are working with IBM to introduce Blockchain to their businesses. These customers are currently testing out IBM's blockchain technology to help small/medium sized enterprises become more evident and attract investment. Another result of working with IBM is that the customers 65

Ivan Homoliak, Dominik Breitenbacher, Alexander Binder, Paweł Szałachowski

No abstract is available for this record.

Wubing Chen, Zhiying Xu, Shuyu Shi, Yang Zhao · 5 authors

Blockchains have received much attention recently since they provide decentralized approaches to the creation and management of value. Many banks, Internet companies, car manufacturers, and even governments worldwide have incorporated or started considering blockchains to improve the security, scalability, and efficiency of their services. In this paper, we survey blockchain applications in different areas. These areas include cryptocurrency, healthcare, advertising, insurance, copyright protection, energy, and societal applications. Our work provides a timely summary for individuals and organizations interested in blockchains. We envision our study to motivate more blockchain applications.

Liehuang Zhu, Baokun Zheng, Meng Shen, Feng Gao · 6 authors

With the more and more extensive application of blockchain, blockchain security has been widely concerned by the society and deeply studied by scholars. Moreover, the security of blockchain data directly affects the security of various applications of blockchain. In this survey, we perform a comprehensive classification and summary of the security of blockchain data. First, we present classification of blockchain data attacks. Subsequently, we present the attacks and defenses of blockchain data in terms of privacy, availability, integrity and controllability. Data privacy attacks present data leakage or data obtained by attackers through analysis. Data availability attacks present abnormal or incorrect access to blockchain data. Data integrity attacks present blockchain data being tampered. Data controllability attacks present blockchain data accidentally manipulated by smart contract vulnerability. Finally, we present several important open research directions to identify follow-up studies in this area.