Blockchain Papers

Aljosha Judmayer, Nicholas Stifter, Alexei Zamyatin, Itay Tsabary · 8 authors

No abstract is available for this record.

Ashish Sharma, Chavikant, Takshi Singh, Tushar Aggarwal · 6 authors

In recent years, the use of the internet to vote has become popular and several governments in Europe and worldwide are intending to experiment with it. Online voting is becoming more popular in today’s culture. Many people are currently benefiting from cold digital technologies. Unlike the election system, it makes far more frequent use of paper. A standard (offline) method poses a security and transparency risk to popular elections. National elections are still centralized, with only one political party in authority. One of the main issues with traditional election systems is the organization that has complete control over the website and system, which might disrupt the database of many opportunities. Because we accept a separate system and the complete database is handled by many people, blockchain technology is one of the answers. The blockchain technology has been employed in a Bitcoin system called as a separate Bank. One of the most fraudulent sources on a website can be reduced by using a blockchain in the distribution of information on electronic voting systems. This research examines the use of a blockchain algorithm to record vote results at all polling sites. It’s no longer necessary to print ballot sheets or open polling stations. The goal of this research is to look into the use of blockchain as an electronic voting mechanism.In this paper, an e-trust voting system is divided into blockchain. The classification system means that the calculation depends on the blockchain segmentation. The voter does not have to trust the election administration in an unreliable system, and the trust is divided among all voters. The entire protocol affects system accuracy. Furthermore, all voters will have cryptographic assurance that their privacy will be safeguarded. The article covers the needs for developing electronic voting systems and identifies legal and technical barriers to employing blockchain as a monitoring service for such systems.

Bolton Bailey, Suryanarayana Sankagiri

The ever-growing size of the Bitcoin UTXO state is a factor preventing nodes with limited storage capacity from validating transactions. Cryptographic accumulators, such as Merkle trees, offer a viable solution to the problem. Full nodes create a Merkle tree from the UTXO set, while stateless nodes merely store the root of the Merkle tree. When provided with a proof, stateless nodes can verify that a transaction’s inputs belong to the UTXO set. In this work, we present a systematic study of Merkle tree based accumulators, with a focus on factors that reduce the proof size. Based on the observation that UTXOs typically have a short lifetime, we propose that recent UTXOs be co-located in the tree. When proofs for different transactions are batched, such a design reduces the per-transaction proof size. We provide details of our implementation of this idea, describing certain optimizations that further reduce the proof size in practice. On Bitcoin data before August 2019, we show that our design achieves a 4.6x reduction in proof size vis-a-vis UTREEXO [10], which is a different Merkle-tree based system designed to support stateless nodes.

Jishnu Bhardwaj, Pulkit Jain, Preeti Nagrath, Mamta Mittal

No abstract is available for this record.

Jeyasheela Rakkini Simon, K. Geetha

The Ethereum blockchain is an open-source, decentralized blockchain with functions triggered by smart contract and has voluminous real-time data for analysis using machine learning and deep learning algorithms. Ether is the cryptocurrency of the Ethereum blockchain. Ethereum virtual machine is used to run Turing complete scripts. The data set concerning a block in the Ethereum blockchain with a block number, timestamp, crypto address of the miner, and the block rewards for the miner are explored for K means clustering for clustering miners with a unique crypto address and their rewards. Linear regression and polynomial regression are used for the prediction of the next block reward to the miner. The Long ShortTerm Memory (LSTM) algorithm is used to exploit the Ether market data set for predicting the next ether price in the market. Every kind of price and volume for every four hours is taken for prediction. The root mean square error of 34.9% is obtained for linear regression, the silhouette score is 71% for K-means clustering of miners with same rewards, with the optimal number of clusters obtained by Gap statistic method.

Fredy Andrés Aponte-Novoa, Ana Lucila Sandoval Orozco, Ricardo Villanueva-Polanco, Pedro M. Wightman

The applications that use blockchain are cryptocurrencies, decentralized finance applications, video games and many others. Most of these applications trust that the blockchain will prevent issues like fraud, thanks to the built-in cryptographic mechanisms provided by the data structure and the consensus protocol. However, blockchains suffers from what is called a 51% attack or majority attack, which is considered a high risk for the integrity of these blockchains, where if a miner, or a group of them, has more than half the computing capability of the network, it can rewrite the blockchain. Even though this attack is possible in theory, it is regarded as hard-achievable in practice, due to the assumption that, with enough active members, it is very complicated to have that much computing power; however, this assumption has not been studied with enough detail. In this work, a detailed characterization of the miners in the Bitcoin and Crypto Ethereum blockchains is presented, with the aim of proving the computing distribution assumption and to creating profiles that may allow the detection of anomalous behaviors and prevent 51% attacks. The results of the analysis show that, in the last years, there has been an increasing concentration of hash rate power in a very small set of miners, which generates a real risk for current blockchains. Also, that there is a pattern in mining among the main miners, which makes it possible to identify out-of-normal behavior.

Snehlata Barde

No abstract is available for this record.

Mar Gimenez-Aguilar, José M. de Fuentes, Lorena González‐Manzano, Carmen Cámara

Permanent availability makes blockchain technologies a suitable alternative for building a covert channel. Previous works have analysed its feasibility in a particular blockchain technology called Bitcoin. However, Ethereum cryptocurrency is gaining momentum as a means to build distributed apps. The novelty of this paper relies on the use of Ethereum to establish a covert channel considering all transaction fields and smart contracts. No previous work has explored this issue. Thus, a mechanism called$Zephyrus$, an information hiding mechanism based on steganography, is developed. Moreover, its capacity, cost and stealthiness are assessed both theoretically, and empirically through a prototype implementation that is publicly released. Disregarding the time taken to send the transaction to the blockchain, its retrieval and the mining time, experimental results show that, in the best case, 40 Kbits can be embedded in 0.57 s. for US$\$ $1.64, and retrieved in 2.8 s.

Gang Huang, Kaidong Wu, Chaoran Luo, Su Zhang · 7 authors

No abstract is available for this record.

Saurabh Singh, A. S. M. Sanwar Hosen, Byungun Yoon

Blockchain technology is becoming increasingly attractive to the next generation, as it is uniquely suited to the information era. Blockchain technology can also be applied to the Internet of Things (IoT). The advancement of IoT technology in various domains has led to substantial progress in distributed systems. Blockchain concept requires a decentralized data management system for storing and sharing the data and transactions in the network. This paper discusses the blockchain concept and relevant factors that provide a detailed analysis of potential security attacks and presents existing solutions that can be deployed as countermeasures to such attacks. This paper also includes blockchain security enhancement solutions by summarizing key points that can be exploited to develop various blockchain systems and security tools that counter security vulnerabilities. Finally, the paper discusses open issues relating to and future research directions of blockchain-IoT systems.

Neyire Deniz Sarier

No abstract is available for this record.

Suat Mercan, Mumin Cebe, Ramazan Aygün, Kemal Akkaya · 6 authors

Abstract A camera footage which is essential for forensic investigations can easily be modified with advanced video tampering techniques. This makes it necessary to employ novel methods to retain and prove the integrity of captured scene in criminal investigations. In this vein, blockchain technology has received a substantial interest in the last decade as it provides trust among users without a trusted third party, which enabled a myriad of applications. To this end, we propose a framework that utilizes blockchain technology to verify integrity of a camera footage recorded by a resource‐constrained wireless Internet of Things (IoT) device. The proposed approach computes the hash of the video data before it leaves the IoT device to ensure the integrity. The hash is then stored on a permissioned blockchain platform that enables detection of tampering in the video. The continuous stream is segmented efficiently to have periodic hash value to minimize the risk of video loss in case of device failure. The system has been implemented on a Raspberry Pi and Hyperledger to validate its efficiency. We are able to process high resolution videos on a resource‐constrained with reasonable amount of delay. The integrity of recorded video is successfully verified by using the digest kept in permissioned blockchain.

Harshal Patil, Shilpa Sharma, Linesh Raja

No abstract is available for this record.

Katarzyna Koptyra, Marek R. Ogiela

Imagechain is a cryptographic structure that chain digital images with hash links. The most important feature, which differentiates it from blockchain, is that the pictures are not stored inside the blocks. Instead, the block and the image are combined together in the embedding process. Therefore, the imagechain is built from standard graphic files that may be used in the same way as any other image, but additionally, each of them contains a data block that links it to a previous element of the chain. The presented solution does not require any additional files except the images themselves. It supports multiple file formats and embedding methods, which makes it portable and user-friendly. At the same time, the scheme provides a high level of security and resistance to forgery. This is achieved by hashing the whole file with embedded data, so the image cannot be altered or removed from the chain without losing integrity. This article describes the basic concept of an imagechain together with building blocks and applications. The two most important issues are embedding methods and block structure.

Philipp Zabka, Klaus-Tycho Förster, Stefan Schmid, Christian Decker

Off-chain networks provide an attractive solution to the scalability challenges faced by cryptocurrencies such as Bitcoin. While first interesting networks are emerging, we currently have relatively limited insights into the structure and distribution of these networks. Such knowledge, however is useful, when reasoning about possible performance improvements or the security of the network. For example, information about the different node types and implementations in the network can help when planning the distribution of critical software updates.

Amna Qureshi, David Megías

In this paper, we provide a holistic survey of multimedia content protection applications in which blockchain technology is being used. A taxonomy is developed to classify these applications with reference to the technical aspects of blockchain technology, content protection techniques, namely, encryption, digital rights management, digital watermarking and fingerprinting (or transaction tracking), and performance criteria. The study of the literature reveals that there is currently no complete and systematic taxonomy dedicated to blockchain-based copyright protection applications. Moreover, the number of successfully developed blockchain-based content protection systems is very low. This points towards a research gap. To fill this gap, we propose a taxonomy that integrates technical aspects and application knowledge and can guide the researchers towards the development of blockchain-based multimedia copyright protection systems. Furthermore, the paper discusses some technical challenges and outlines future research directions.

Zeba Mahmood, Vacius Jusas

Block-chain emerged as the technology of choice for most applications because of its immutability property. Block-chain's immutability property promotes network resilience against any removal or modification of data stored on the ledger. However, large scale networks such as the Internet of Things (IoT) that may contain millions of nodes can significantly increase Block-chain size and raise serious privacy challenges. Moreover, the General Data Protection Regulations (GDPRs) that were enforced in May 2018 by European countries allows individuals and organizations to take control of their data by establishing stringent rules which includes “the right to be forgotten”. In cases where there are ethical or legal reasons individuals and companies might want their personal data stored to be erased whether such data is stored locally or on the ledger. The philosophy underpinning Block-chains is that forcing nodes to erase data is akin to denying them a role to play in the Block-chain ecosystems as full nodes. In this paper, we attempt to challenge this notion by proposing a model framework for an enhanced privacy that is akin to Block-chain erasure. Our approaches combine ring signatures (that have long been used to generate anonymous signatures) and Zero-Knowledge Proofs (ZKPs) that can help to disguise user's wallet addresses.

Suvadra Barua, Dipon Talukder

Contents that are uploaded on the centralized video platform are mostly controlled by the platform owner instead of the content creator. On the other hand, decentralized blockchain-based video platforms are trying to decrease ad pressure and removes intermediaries but some content creators upload garbage content to earn free cryptocurrency, generated by the blockchain algorithm which demoralizes other creative content makers. Also, copyright infringement, illegal distribution of protected content is a big issue in mainstream video platforms. Therefore, copyright protection, illegal access control and legitimate video file distribution are needed with proper pay off for the creator's creative content. The paper proposes a composition of robust copyright protection algorithm, a secured encryption method and access control system designed with modified version of IPFS and Ethereum Smart Contract to develop an effective Blockchain-based decentralized video streaming platform.

Syada Tasmia Alvi, Mohammed Nasir Uddin, Linta Islam, Sajib Ahamed

Democracy plays a significant part in voting. If the voting process is not clear, stable and tamper proof, the integrity and legitimacy of the entire system is at risk. In recent years, neither civilians nor elected leaders have appreciated traditional ballots. Elections are surrounded by vote falsification, bribery and other voting problems. Often an individual must stand in a long line of people while casting votes and the procedure is quite lengthy. There has to be an exceptional feature of modern technologies to upgrade the existing system. Block chain provides the various features that will alter the scenario. But to implement ethereum based blockchain is expensive as for each transaction there is a computation cost. So we have used the sidechain concept to provide a cost effective blockchain based voting mechanism as sidechain extends the capabilities of blockchain by performing some operation besides it using duplicate currency and returns the result to mainchain for its use.

Enis Karaarslan, Enis Konacaklı

We have entered an era where the importance of decentralized solutions has become more obvious. Blockchain technology and its derivatives are distributed ledger technologies that keep the registry of data between peers of a network. This ledger is secured within a successive over looping cryptographic chain. The accomplishment of the Bitcoin cryptocurrency proved that blockchain technology and its derivatives could be used to eliminate intermediaries and provide security for cyberspace. However, there are some challenges in the implementation of blockchain technology. This chapter first explains the concept of blockchain technology and the data that we can store therein. The main advantage of blockchain is the security services that it provides. This section continues by describing these services.. The challenges of blockchain; blockchain anomalies, energy consumption, speed, scalability, interoperability, privacy and cryptology in the age of quantum computing are described. Selected solutions for these challenges are given. Remarkable derivatives of blockchain, which use different solutions (directed acyclic graph, distributed hash table, gossip consensus protocol) to solve some of these challenges are described. Then the data storage in blockchain and evolving data solutions are explained. The comparison of decentralized solutions with the lcentralized database systems is given. A multi-platform interoperable scalable architecture (MPISA) is proposed. In the conclusion we include the evolution assumptions of data storage in a decentralized world.

Ahmed H. Madkour, Asmaa Elsaid, Hatem Abdelkader

Most Bitcoin systems use blockchain technology to store all historical transaction data. Blockchain is a linked list structure but may be changed to a fork structure; a useful fork or an intentional fork. The useful fork may occur when the rules of the block are updated. On the other side, the intentional fork occurs when a miner has supercomputer properties that generate a set of blocks as a branch and does not publish this branch to the blockchain until the length of that branch is greater than the length of the main branch. When this fork occurs in the system, a set of blockchain transactions will be rollbacked, user waiting times increases, and miner rewards increases illegally. In this paper, the Lightweight algorithm is proposed to avoid the intentional fork issue and therefore rollback issue, users waiting time is reduced in the transaction process. The proposed algorithm is to make a single publisher in the system and divides the block construction into two phases. In the first phase, a miner generates a block and sends it to the memory pool. In the second phase, the memory pool will publish the block to the blockchain. The results show that the proposed algorithm has a good ability to avoid the intentional fork issue in the blockchain and the rollback issue thus minimize user waiting times.

Zhensheng Gao, Lifeng Cao, Xuehui Du

In the era of big data, the ownership of digital asset has become an important issue that people concern about. Traditional means of data right confirmation adopt the mode of submitting the ownership evidence and authority reviewing, but there are uncontrollable factors such as potential tampering. In order to solve this problem, a data right confirmation mechanism based on blockchain and locality sensitive hashing is proposed. First, blockchain technology is used to handle the matter of trust in data right confirmation, and a user identity management scheme based on Hyperledger Fabric is proposed to ensure the credibility of the identity of the confirmation entity. Secondly, a data fingerprint extraction scheme based on locality sensitive hashing is proposed, and it is used to maintain the consistency of the fingerprints stored on the blockchain and the data disseminated off the blockchain. Finally, the chaincode deployed on Hyperledger is developed to support the submitting, verification and notarization of confirmation transactions. And the security SDK components are developed to interact with the chaincode. The result of experiment shows that this mechanism can effectively discover the infringement of data resources with the appropriate parameters.

Ahmed H. Madkour, Hatem Abdelkader, Asmaa Elsaid

Blockchain is considered the most secure technology in data storing, which stores data in blocks. Therefore. Blockchain is a linked list structure but may be changed to a fork structure; a usefulfork or a malicious fork. The usefulfork may occur when the rules of the block are updated. On the other side, the malicious fork occurs when a miner has supercomputer properties that generate a set of blocks as a branch and does not publish this branch to the blockchain until the length of that branch is greater than the length of the main branch, or when two blocks saved at the same time in the blockchain. TVhen theseforks occur in the systenb a set of blockchain transactions will be rollbacked, user waiting times increases, and miner rewards increases illegally. In this paper, a Lightweight algorithm is proposed to avoid the malicious fork issue, and therefore rollback issue, users waiting time is reduced in the transaction process. The proposed algorithm is to make a single publisher in the system and divides the block construction into two phases. In the first phase, a miner generates a block and sends it to the memory pool. In the second phase, the memory pool will publish the block to the blockchain. The results show that the proposed algorithm has a good ability to avoid the malicious fork issue in the blockchain and the rollback issue thus minimize user waiting times.

Pengpeng Gu, Liquan Chen

The existing cross-domain authentication mechanisms are established based on well-known Public Key Infrastructure (PKI) systems, where digital certificates issued by Certificate Authority(CA) serve to authenticate the identity of entities. The complex authentication path, accompanied by multiple signatures and verifications, causes low authentication efficiency. In addition, resulting from an “update gap” between Certificate Revocation List(CRL) and Online Certificate Status Protocol(OCSP) mechanism, the revoked certificates will be exposed to DDoS attacks. For addressing aforementioned two challenges, an efficient blockchain-based authentication and secure certificate revocation scheme is proposed. Based on the non-tamperability and traceability of the blockchain, the signature module of X.509 digital certificate is replaced by the certificate hash value which serves as the trust certificate between domains. Furthermore, a consensus algorithm is adopted for random number hash broadcasting to improve efficiency. Theoretical analysis shows the proposed scheme has the security characteristics of non-repudiation, anonymity and anti DDoS attack. The experimental results demonstrate the proposed scheme has the advantage over existing cross-domain authentication and certificate revocation scheme at communication and computing cost and security respectively.