Blockchain Papers

Liehuang Zhu, Baokun Zheng, Meng Shen, Shui Yu · 8 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.

Ho-Kyung Yang, Hyun-Jong Cha, You-Jin Song

With the recent increase in the number of IoT devices and the development of centralized management systems, risks in cyber space, including personal information phishing, malicious code infection, hacking, and DDos attack, are becoming major issues in the real world. The recently developed distributed data management technology, blockchain, provides reliability in transactions without the intervention of a third party. This new technology, blockchain, promotes integrity and reliability of transaction records by allowing for all network participants to jointly own and verify data, which was previously done by a central server. Due to distributed data management, the technology can reduce brokerage fees and construction costs, and guarantees high levels of integrity and security of data. This paper examines the effective identifier management using blockchain technology under the named data networking environment. The proposed system does not expose a specific user's identifier by creating a transaction using the content name of the identifier. The identifier can be safely stored and managed through such an identifier split management technique.

Fei Gao

Aiming at the poor encryption effect existing in the data encryption algorithm of e-commerce platform, and the data lost and distorted easily after encrypting, a data encryption algorithm based on blockchain technology is proposed in this paper. By analyzing the symmetric key algorithm and the public key algorithm, the DES encryption algorithm is described in detail. The two related technologies of digital envelopes and message authentication are analyzed to ensure the accuracy of the data and the one time encryption of the data. Based on this, in order to ensure the effectiveness of encryption, the process of asymmetric encryption algorithm based on chaotic sequence of neural network and asymmetric encryption algorithm based on neural network chaotic attractor are analyzed, and the security is tested. While ensuring the accuracy of data, it improves the effect of data encryption and realizes the encryption of e-commerce platform data, which is to realize data encryption algorithm based on blockchain technology. Experimental results show that the~proposed algorithm can encrypt the data of e-commerce platform, and the encryption process is relatively simple, the encryption effect is better, and the accuracy of the encrypted data is relatively high, which provides a theoretical basis for further research of the subject.

Licheng Wang, Xiaoying Shen, Jing Li, Jun Shao · 5 authors

Blockchain, as one of the crypto-intensive creatures, has become a very hot topic recently. Although many surveys have recently been dedicated to the security and privacy issues of blockchains, there still lacks a systematic examination on the cryptographic primitives in blockchains. To this end, we in this paper conduct a systematic study on the cryptographic primitives in blockchains by comprehensive analysis on top-30 mainstream cryptocurrencies, in terms of the usages, functionalities, and evolutions of these primitives. We hope that it would be helpful for cryptographers who are going to devote themselves to the blockchain research, and the financial engineers/managers who want to evaluate cryptographic solutions for blockchain-based projects.

Zijian Bao, Bin Wang, Yongxin Zhang, Qinghao Wang · 5 authors

We propose Lockcoin, a secure and privacy-preserving mix service for bitcoin anonymity. We introduce mix servers to provide mix service for user to prevent attackers linking the input address with output address by using blind signature shceme, multisignature scheme. Lockcoin provides anonymity, scalability, bitcoin compatibillity, theft impossibility and accountability. We have proposed a prototype of Lockcoin based on bitcoin test network, experimental results show that our solution is efficient. Lockcoin's source codes are released on github.com/Northeastern-University-Blockchain/Lockcoin.

Sirine Sayadi, Sonia Ben Rejeb, Zièd Choukair

With the increasing number of connected devices and the number of online transactions today, managing all these transactions and devices and maintaining network security is a research issue. Current solutions are mainly based on cloud computing infrastructures, which require servers high-end and broadband networks to provide data storage and computing services. These solutions have a number of significant disadvantages, such as high maintenance costs of centralized servers, critical weakness of Internet Of Things applications, security and trust issues, etc. The blockchain is seen as a promising technique for addressing the mentioned security issues and design new decentralization frameworks. However, this new technology has a great potential in the most diverse technological fields. In this paper, we focus on presenting an overview of blockchain technology, highlighting its advantages, limitations and areas of application. The originality of this work resides in the comparison between the different blockchain systems and their security schemes and the perspective of integrating this technology into secured systems models for our comfort and our private life.

Michael Kerr, Fengling Han, Ron van Schyndel

Presented here is a functional implementation of Distributed Ledger Technology applied to the task of cataloguing CCTV video evidence. We describe and demonstrate a prototype camera that participates in blockchain creation in real time, and the system designed to manage and coordinate its distribution and use. This application is of specific interest to law enforcement agencies charged with the management of high volumes of CCTV evidence. We discuss applicability and scalability with reference to simulation results and real-world testing. The combination of blockchain technology with a novel digital watermarking application is demonstrated here providing immediate benefit against an existing real-world problem of trustworthy evidence protection in distributed network environments.

Oğuzhan TAŞ, Farzad Kiani

Son zamanlarda; blok zinciri tabanlı kripto para ödeme sistemleri(bitcoin, ethereum) oldukça popüler olmuştur. Merkezi olmayan eşler arası(P2P) ağ yapısına sahip olan bu sistemde tüm işlemler, sadece ekleme yapılabilen bir ana defterde(ledger) tutulmaktadır. Madenciler ise bu ağ yapısındaki düğümleri oluşturmaktadır, her madenci defterin yerel kopyasına sahiptir. Blok zincirinde, PoW uzlaşma protokolü işlemi onaylamakta ve zincire yeni blok eklenmesine izin vermektedir. Ödülü almak için, madenciler eşler arası ağda işlemi tamamlamak için birbirleriyle yarışırlar. Ödül sistemi, blok zinciri kullanan bitcoin’i popülerleştirmiş, fakat aynı zamanda saldırganların blok zincirine ilgisini artırmıştır. Saldırganlar tarafından blok zincirinin madenci havuzuna ve ağ yapısının güvenliğine farklı saldırılar yapılmıştır. Bu makalede, blok zinciri alt yapısına karşı mevcut saldırılar sunulmuştur. İlk bölümlerde, P2P mimarisine, uzlaşma protokolüne ve işlemlere yönelik saldırı tipleri araştırılmıştır. Bu bölümde, %51 saldırısı, Çift harcama, Finney, Vector76, Kaba Kuvvet, Sybil, Eclipse, Denge gibi saldırılar açıklanmış ve çözümler önerilmiştir. Daha sonra, Bencil madencilik ve Blok Atma, Blok Tutma(BWH), Blok Tutma Sonrası Çatallanma(FAW), Havuz sıçrama saldırısı, Cezalandırıcı Çatallanma ile Kara Listeye Alma, Köpük saldırısı ve Rüşvet Saldırısı gibi madencilik havuzuna karşı saldırılar incelenmiş ve savunma stratejileri sunulmuştur. Son bölümde de blok zinciri altyapısında kullanılan kriptografi’nin geleceği üzerinde tartışılmış ve Post Kuantum Kriptografi’nin etkilerinden bahsedilmiştir

Yong Yu, Yujie Ding, Yanqi Zhao, Yannan Li · 7 authors

Currently, the number of Internet of Thing (IoT) devices making up the IoT is more than 11 billion and this number has been continuously increasing. The prevalence of these devices leads to an emerging IoT business model called Device-as-a-service(DaaS), which enables sensor devices to collect data disseminated to all interested devices. The devices sharing data with other devices could receive some financial reward such as Bitcoin. However, side-channel attacks, which aim to exploit some information leaked from the IoT devices during data trade execution, are possible since most of the IoT devices are vulnerable to be hacked or compromised. Thus, it is challenging to securely realize data trading in IoT environment due to the information leakage such as leaking the private key for signing a Bitcoin transaction in Bitcoin system. In this paper, we propose LRCoin, a kind of leakage-resilient cryptocurrency based on bitcoin in which the signature algorithm used for authenticating bitcoin transactions is leakage-resilient. LRCoin is suitable for the scenarios where information leakage is inevitable such as IoT applications. Our core contribution is proposing an efficient bilinear-based continual-leakage-resilient ECDSA signature. We prove the proposed signature algorithm is unforgeable against adaptively chosen messages attack in the generic bilinear group model under the continual leakage setting. Both the theoretical analysis and the implementation demonstrate the practicability of the proposed scheme.

Hiroki Watanabe, Shigenori Ohashi, Shigeru Fujimura, Atsushi Nakadaira · 6 authors

Bitcoin's enormous success has inspired the development of alternative blockchains, such as consortium chains. Several cross-chain protocols have been proposed as ways of connecting these universes of individual blockchains in a distributed and secure manner. In this paper, we present Niji, a new cross-chain protocol that allows parties to perform virtual Bitcoin payment securely on a consortium chain, without any trusted third-party or mediators. Our work focuses on the issue that it is difficult for a consortium chain's token to hold a stable market value, and Niji makes it possible for smart contract services to acquire means of payment in the consortium chain. With the Bitcoin payment channel built on the consortium chain, the process from payment to service provision runs autonomously without any interaction between parties. Niji introduces the concept of a transaction template to validate Bitcoin payments efficiently on different blockchains, and it allows a service provider to delegate all of its tasks for verifying state updates to a smart contract on the consortium chain. We also propose a novel bi-directional payment channel adapted for design of the Niji protocol, which can update payments non-interactively between parties. We implemented a prototype of the Niji protocol and conducted an experiment measuring the computational cost and latency that demonstrates the protocol's feasibility on practical platforms.

Dharmendra Kumar, D. V. Chandini, B. Dinesh Reddy, Debnath Bhattacharyya · 5 authors

The Secure Electronic Voting System using Blockchain Technology is ensured to make the current voting process to take place in an honest, accurate and highly secure way. This system stores the details of the voters and votes in two separate blockchains, which provides transparency into election results by allowing voters to independently audit the ballot box while protecting each voter's right to privacy. All the details of the voters get stored into one Blockchain, and this guarantees greater security by providing a PIN confirmed before the vote is taken into consideration. By casting votes as transactions, we can create another blockchain which keeps track of the tallies of the votes. This way, everyone can count the votes themselves, they can verify that no votes were changed or removed, and no illegitimate votes were added and as a result, is made public everyone can agree upon the final count. This system is only taking the current process of voting in an election and bringing that process entirely online, in an attempt to make it highly secure and also more accessible by allowing the voter to vote at his/her location and also reducing the effort put by staff members.

Ruben Recabarren, Bogdan Cărbunar

Abstract Providing reliable and surreptitious communications is difficult in the presence of adaptive and resourceful state level censors. In this paper we introduce Tithonus, a framework that builds on the Bitcoin blockchain and network to provide censorship-resistant communication mechanisms. In contrast to previous approaches, we do not rely solely on the slow and expensive blockchain consensus mechanism but instead fully exploit Bitcoin’s peer-to-peer gossip protocol. We develop adaptive, fast and cost effective data communication solutions that camouflage client requests into inconspicuous Bitcoin transactions. We propose solutions to securely request and transfer content, with unobservability and censorship resistance, and free, pay-per-access and subscription based payment options. When compared to state-of-the-art Bitcoin writing solutions, Tithonus reduces the cost of transferring data to censored clients by 2 orders of magnitude and increases the goodput by 3 to 5 orders of magnitude. We show that Tithonus client initiated transactions are hard to detect, while server initiated transactions cannot be censored without creating split world problems to the Bit-coin blockchain.

Zhaofeng Ma, Weihua Huang, Hongmin Gao

With the development of Internet technology, transmitting, editing and misusing the digital multimedia bring great challenges in misusing detection for multimedia content protection. In this paper we proposed an artwork image digital rights management scheme for Internet misusing detection based on watermark and blockchain with robustness and high-level security. We embed artwork right information such as author, RightHolder, Date and Location information into the artwork image data. In the scheme, we use image Arnold transform to enhance the security and use image DCT coefficients of middle frequency to embed watermark for robustness. In the transparence of watermark, HVS and Watson models are used to control the watermark strength, which can enhance the invisibility. Once the suspicious image data from Internet are misused and spreading the image data on Internet without authorization, especially the high value artwork image data, we can trace the misuse responsibility by extracting the watermark. And according to the above algorithm, we implemented the scheme as DRMChain based on the consortium blockchain which stored the artwork and DRM information in an un-tampered ledger for decentralized rights confirmation. Large amount of experiments indicate the proposed watermark-based trusted blockchain DRM scheme is secure, robust, and for the protection and misuse detection of image data.

Clement Chan Zheng Wei, Chuah Chai Wen

Current electronic voting protocol require a centralized system to control the whole procedure from ballot inputs to result outputs and election monitoring. Meanwhile, blockchain technology provide a decentralized system which open across the whole network of untrusted participants. Applying blockchain technology into electronic voting protocol through a proper architecture can instil characteristic such as data confidentiality, data integrity and data authenticity. In this paper, we going to discuss a proposed method on how to leverage the advantages from blockchain into electronic voting protocol. This blockchain-based electronic voting protocol promise to provide a secure electronic election process given the proposed system works. We implement a protocol using blockchain to turn election protocol into an automated control system without relying any single point of entity. Lastly, we discuss the characteristics of our proposed blockchain-based electronic voting protocol in this paper. However, there are also emerging challenges and limitations awaiting to overcome. This paper gives a comprehensive overview of our proposed protocol.

Somdip Dey

Blockchain's vast applications in different industries have drawn several researchers to pursue extensive research in securing blockchain technologies. In recent times we could see several institutions coming together to create consortium based blockchain networks such as Hyperledger. Although for applications of blockchain such as Bitcoin, Litcoin, etc. the majority-attack might not be a great threat but for consortium based blockchain networks where we could see several institutions such as public, private, government, etc. are collaborating, the majority-attack might just prove to be a prevalent threat if collusion among these institutions takes place. This paper proposes a methodology where we can use intelligent software agents to monitor the activity of stakeholders in the blockchain networks to detect anomaly such as collusion, using supervised machine learning algorithm and algorithmic game theory and stop the majority attack from taking place.

Juha Partala

Blockchain is a public open ledger that provides data integrity in a distributed manner. It is the underlying technology of cryptocurrencies and an increasing number of related applications, such as smart contracts. The open nature of blockchain together with strong integrity guarantees on the stored data makes it a compelling platform for covert communication. In this paper, we suggest a method of securely embedding covert messages into a blockchain. We formulate a simplified ideal blockchain model based on existing implementations and devise a protocol that enables two parties to covertly communicate through the blockchain following that model. We also formulate a rigorous definition for the security and covertness of such a protocol based on computational indistinguishability. Finally, we show that our method satisfies this definition in the random oracle model for the underlying cryptographic hash function.

Wei Bi, Xiaoyun Jia, Maolin Zheng

Most cryptocurrency systems or systems based on blockchain technology are currently using the elliptic curves digital signature algorithm (ECDSA) on the secp256k1 curve, which is susceptible to backdoors implemented by the curve creator (secp256k1). The paper proposes a multiple elliptic curves digi-tal signature algorithm (MECDSA), which allows not only for setting the number of elliptic curves according to practical security requirements, but also for editing the parameters of each elliptic curve. The performance analy-sis proves that the scheme is secure and efficient, and can avoid any back-doors implemented by curve creators. We suggest that the systems based on blockchain should operate in two elliptic curves considering the contradic-tion between security and efficiency.

Jan Rüth, Torsten Zimmermann, Konrad Wolsing, Oliver Hohlfeld

Mining is the foundation of blockchain-based cryptocurrencies such as Bitcoin rewarding the miner for finding blocks for new transactions. The Monero currency enables mining with standard hardware in contrast to special hardware (ASICs) as often used in Bitcoin, paving the way for in-browser mining as a new revenue model for website operators. In this work, we study the prevalence of this new phenomenon. We identify and classify mining websites in 138M domains and present a new fingerprinting method which finds up to a factor of 5.7 more miners than publicly available block lists. Our work identifies and dissects Coinhive as the major browser-mining stakeholder. Further, we present a new method to associate mined blocks in the Monero blockchain to mining pools and uncover that Coinhive currently contributes 1.18% of mined blocks having turned over 1293 Moneros in June 2018.

Jia Kan, Shangzhe Chen, Xin Huang

Blockchain technology is ushering in another break-out year, the challenge of blockchain still remains to be solved. This paper analyzes the features of Bitcoin and Bitcoin-NG system based on blockchain, proposes an improved method of implementing blockchain systems by replacing the structure of the original chain with the graph data structure. It was named GraphChain. Each block represents a transaction and contains the balance status of the traders. Additionally, as everyone knows all the transactions in Bitcoin system will be baled by only one miner that will result in a lot of wasted effort, so another way to improve resource utilization is to change the original way to compete for miner to election and parallel mining. Researchers simulated blockchain with graph structure and parallel mining through python, and suggested the conceptual new graph model which can improve both capacity and performance.

Deeraj Nagothu, Ronghua Xu, Seyed Yahya Nikouei, Yu Chen

While the smart surveillance system enhanced by the Internet of Things (IoT) technology becomes an essential part of Smart Cities, it also brings new concerns in security of the data. Compared to the traditional surveillance systems that is built following a monolithic architecture to carry out lower level operations, such as monitoring and recording, the modern surveillance systems are expected to support more scalable and decentralized solutions for advanced video stream analysis at the large volumes of distributed edge devices. In addition, the centralized architecture of the conventional surveillance systems is vulnerable to single point of failure and privacy breach owning to the lack of protection to the surveillance feed. This position paper introduces a novel secure smart surveillance system based on microservices architecture and blockchain technology. Encapsulating the video analysis algorithms as various independent microservices not only isolates the video feed from different sectors, but also improve the system availability and robustness by decentralizing the operations. The blockchain technology securely synchronizes the video analysis databases among microservices across surveillance domains, and provides tamper proof of data in the trustless network environment. Smart contract enabled access authorization strategy prevents any unauthorized user from accessing the microservices and offers a scalable, decentralized and fine-grained access control solution for smart surveillance systems.

Seyed Yahya Nikouei, Ronghua Xu, Deeraj Nagothu, Yu Chen · 6 authors

Information from surveillance video is essential for situational awareness (SAW). Nowadays, a prohibitively large amount of surveillance data is being generated continuously by ubiquitously distributed video sensors. It is very challenging to immediately identify the objects of interest or zoom in suspicious actions from thousands of video frames. Making the big data indexable is critical to tackle this problem. It is ideal to generate pattern indexes in a real-time, on-site manner on the video streaming instead of depending on the batch processing at the cloud centers. The modern edge-fog-cloud computing paradigm allows implementation of time sensitive tasks at the edge of the network. The on-site edge devices collect the information sensed in format of frames and extracts useful features. The near-site fog nodes conduct the contextualization and classification of the features. The remote cloud center is in charge of more data intensive and computing intensive tasks. However, exchanging the index information among devices in different layers raises security concerns where an adversary can capture or tamper with features to mislead the surveillance system. In this paper, a blockchain enabled scheme is proposed to protect the index data through an encrypted secure channel between the edge and fog nodes. It reduces the chance of attacks on the small edge and fog devices. The feasibility of the proposal is validated through intensive experimental analysis.

Cyril Grunspan, Ricardo Pérez-Marco

We propose a decentralized routing algorithm that can be implemented in Bitcoin Lightning Network. All nodes in the network contribute equally to path searching. The algorithm is inspired from ant path searching algorithms.

MohammadJavad Hajialikhani, MohammadMahdi Jahanara

Bitcoin and Ethereum are novel mechanisms for decentralizing the concept of money and computation. Extending decentralization to the human identity concept, we can think of using blockchain for creating a list of verified human identities with a one-person-one-ID property. UniqueID is a Decentralized Autonomous Organization(DAO) for maintaining human identities such that every physical human entity can have no more that one account. One part of this identity is simply the user's claim on one of his unique, permanent, and measurable characteristics -biometrics. Blockchain has proved its integrity as a platform for storing and performing computations on such claims. The biggest challenge here is to ensure that the user has submitted his own valid biometric data. Human verifiers can check if there is any inconsistency in other users' data, by peer-to-peer checks. For preventing bad behavior and centralization in the verification process, UniqueID benefits from novel governance mechanisms to choose verifiers and punish unjust ones. Also, there are incentives for honest verifiers and users by newly generated tokens. We show how the users' privacy can be preserved by using state-of-the-art cryptographic techniques, and so they can use their identity without any concerns for votings, financial and banking purposes, social media accounts, reputation systems etc.

Tooba Faisal, Nicolas T. Courtois, Antoaneta Serguieva

The use of blockchains is growing every day, and their utility has greatly expanded from sending and receiving crypto-coins to smart-contracts and decentralized autonomous organizations. Modern blockchains underpin a variety of applications: from designing a global identity to improving satellite connectivity. In our research we look at the ability of blockchains to store metadata in an increasing volume of transactions and with evolving focus of utilization. We further show that basic approaches to improving blockchain privacy also rely on embedding metadata. This paper identifies and classifies real-life blockchain transactions embedding metadata of a number of major protocols running essentially over the bitcoin blockchain. The empirical analysis here presents the evolution of metadata utilization in the recent years, and the discussion suggests steps towards preventing criminal use. Metadata are relevant to any blockchain, and our analysis considers primarily bitcoin as a case study. The paper concludes that simultaneously with both expanding legitimate utilization of embedded metadata and expanding blockchain functionality, the applied research on improving anonymity and security must also attempt to protect against blockchain abuse.