Blockchain Papers

Qiuhua Xu, Yixuan Zhang, Ziyang Zhang

No abstract is available for this record.

Syed Muhammad Danish, Marios Lestas, Hassaan Khaliq Qureshi, Kaiwen Zhang · 6 authors

No abstract is available for this record.

Laura A. Franke, Marco Schletz, Søren Salomo

This paper examines the benefits and constraints of applying blockchain technology for the Paris Agreement carbon market mechanism and develops a list of technical requirements and soft factors as selection criteria to test the feasibility of two different blockchain platforms. The carbon market mechanism, as outlined in Article 6.2 of the Paris Agreement, can accelerate climate action by enabling cooperation between national Parties. However, in the past, carbon markets were limited by several constraints. Our research investigates these constraints and translates them into selection criteria to design a blockchain platform to overcome these past limitations. The developed selection criteria and assumptions developed in this paper provide an orientation for blockchain assessments. Using the selection criteria, we examine the feasibility of two distinct blockchains, Ethereum and Hyperledger Fabric, for the specific use case of Article 6.2. These two blockchain systems represent contrary forms of design and governance; Ethereum constitutes a public and permissionless blockchain governance system, while Hyperledger Fabric represents a private and permissioned governance system. Our results show that both blockchain systems can address present carbon market constraints by enhancing market transparency, increasing process automation, and preventing double counting. The final selection and blockchain system implementation will first be possible, when the Article 6 negotiations are concluded, and governance preferences of national Parties are established. Our paper informs about the viability of different blockchain systems, offers insights into governance options, and provides a valuable framework for a concrete blockchain selection in the future.

Tianyu Sun, Wensheng Yu

Blockchain technology has attracted more and more attention from academia and industry recently. Ethereum, which uses blockchain technology, is a distributed computing platform and operating system. Smart contracts are small programs deployed to the Ethereum blockchain for execution. Errors in smart contracts will lead to huge losses. Formal verification can provide a reliable guarantee for the security of blockchain smart contracts. In this paper, the formal method is applied to inspect the security issues of smart contracts. We summarize five kinds of security issues in smart contracts and present formal verification methods for these issues, thus establishing a formal verification framework that can effectively verify the security vulnerabilities of smart contracts. Furthermore, we present a complete formal verification of the Binance Coin (BNB) contract. It shows how to formally verify the above security issues based on the formal verification framework in a specific smart contract. All the proofs are checked formally using the Coq proof assistant in which contract model and specification are formalized. The formal work of this paper has a variety of essential applications, such as the verification of blockchain smart contracts, program verification, and the formal establishment of mathematical and computer theoretical foundations.

Yeṣem Kurt Peker, Xavier Rodríguez, James Ericsson, Suk Jin Lee · 5 authors

Blockchain is a developing technology that can be utilized for secure data storage and sharing. In this work, we examine the cost of Blockchain-based data storage for constrained Internet of Things (IoT) devices. We had two phases in the study. In the first phase, we stored data retrieved from a temperature/humidity sensor connected to an Ethereum testnet blockchain using smart contracts in two different ways: first, appending the new data to the existing data, storing all sensor data; and second, overwriting the new data onto the existing data, storing only a recent portion of the data. In the second phase, we stored simulated data from several sensors on the blockchain assuming sensor data is numeric. We proposed a method for encoding the data from the sensors in one variable and compared the costs of storing the data in an array versus storing the encoded data from all sensors in one variable. We also compared the costs of carrying out the encoding within the smart contract versus outside the smart contract. In the first phase, our results indicate that overwriting data points is more cost-efficient than appending them. In the second phase, using the proposed encoding method to store the data from several sensors costs significantly less than storing the data in an array, if the encoding is done outside the smart contract. If the encoding is carried out in the smart contract, the cost is still less than storing the data in an array, however, the difference is not significant. The study shows that even though expensive, for applications where the integrity and transparency of data are crucial, storing IoT sensor data on Ethereum could be a reliable solution.

M. Hrishikesh, Shirohiya Mayur, Hemadri L Sidnag, B Ravishankar · 5 authors

Rural workers today are facing unemployment issues due to unorganized work sector in the construction domain. Local contractors hire these workers on a first-come-first-serve daily wage basis until they fulfill their capacity. This method has been observed to be ineffective as it depends on the demographic of the location. This paper exhibits an implement of a Blockchain network, which ensures the supply chain visibility thus, seamlessly connecting all stakeholders of the supply chain network who are a part of the Blockchain ecosystem. This paper also exhibits the use of Mathematical metrics such as the cosine similarity index which helps us determine the closeness of two or more tensors and Operations Research which help us optimize the allocation of jobs. These computations are performed with the help of the smart contracts, which are incorporated in the Ethereum Blockchain network. The transactions are later verified, and blocks are created. This approach will incorporate a trust factor in the Blockchain transactions and tackle the growing concern of unemployment in the country.

Nakhoon Choi, Heeyoul Kim

Recently, with the increase of smart factories, smart cities, and the 4th industrial revolution, internal user authentication is emerging as an important issue. The existing user authentication and Access Control architecture can use the centralized system to forge access history by the service manager, which can cause problems such as evasion of responsibility and internal corruption. In addition, the user must independently manage the ID or physical authentication medium for authentication of each service, it is difficult to manage the subscribed services. This paper proposes a Hybrid blockchain-based integrated ID model to solve the above problems. The user creates authentication information based on the electronic signature of the Ethereum Account, a public blockchain, and provides authentication to a service provider composed of a Hyperledger Fabric, a private blockchain. The service provider ensures the integrity of the information by recording the Access History and authentication information in the Internal-Ledger. Through the proposed architecture, we can integrate the physical pass or application for user authentication and authorization into one Unification ID. Service providers can prevent non-Repudiation of responsibility by recording their authority and access history in ledger.

Jaideep Kaur Mudhar, Sheetal Kalra, Jyoteesh Malhotra

IoT Devices have revolutionized how people interact with each other and their surroundings, with Gartner predicting 50 billion devices by 2020. IoT devices emerging from WSN to RFIDs are capable of sensing, actuating and sharing data but are resource-constrained devices meaning these devices have limited memory, storage, and computation power. Thus, IoT devices are incapable of securing themselves from various security and privacy threats. Moreover, current Cloud-IoT architectures are centralized; managed and controlled by Trusted Third parties also individuals have no control over their data. Fog-IoT integration has better latency, response time and is much secure compared to Cloud-IoT integration. Recently, Blockchain emerged as a decentralized, highly trusted and tamper-proof technology. In this paper, we proposed a blockchain-based scheme for secure User authentication access to Fog enabled IoT devices. The proposed scheme utilizes the Ethereum Smart Contract. We developed our smart contract using Solidity language with Remix-IDE and tested its functionalities on two test networks Test RPC (Ganache) and Rinkeby Test Network. We also analyzed security vulnerabilities of our smart contract on the ChainSecurity analyzing tool.

G. A. Pierro, Roberto Tonelli

Smart Contracts are computer programs which implement and execute transactions and manage business logic on a decentralized public ledger. Smart Contracts can be written in different programming languages and for different Blockchains. Currently the most used language for Smart Contracts is Solidity and the most used platform is the Ethereum Blockchain. Assessing the quality of Smart Contract programs is an important task required to professional programmers, especially when a programming language has so powerful economic implications. It is therefore crucial to provide professional programmers with tools for the evaluation of Smart Contracts. In software engineering, software metrics has been defined and used to measure software quality and, more in general, to qualify software under the principle “You Can't Manage What You Don't Measure”. For the Solidity programming language there are only a few Standalone Applications to analyse the Smart Contract metrics. The aim of this paper is first to build a tool for the practical computation of a specific set of Solidity source code metrics, so that the set will be extensible in the future according also to Solidity compiler evolution, second to fully enable a web-based usage of the tool to access the metrics of the Solidity programming language. The tool, PASO, differently from the existing application, is able to give software metrics values for Smart Contracts written in Solidity programming language just using a web browser.

Yun Zhang, Zhi Tang, Jing Huang, Yue Ding · 7 authors

The copyright of data is a key point that needs to be solved in spatial data infrastructure for data sharing. In this paper, we propose a decentralized digital rights management model of spatial data, which can provide a novel way of solving the existing copyright management problem or other problems in spatial data infrastructure for data sharing. An Ethereum smart contract is used in this model to realize spatial data digital rights management function. The InterPlanetary File System is utilized as external data storage for storing spatial data in the decentralized file system to avoid data destruction that is caused by a single point of failure. There is no central server in the model architecture, which has a completely decentralized nature and it makes spatial data rights management not dependent on third-party trust institutions. We designed three spatial data copyright management algorithms, developed a prototype system to implement and test the model, used the smart contract security verification tool to check code vulnerabilities, and, finally, discussed the usability, scalability, efficiency, performance, and security of the proposed model. The result indicates that the proposed model not only has diversified functions of copyright management compared with previous studies on the blockchain-based digital rights management, but it can also solve the existing problems in traditional spatial data infrastructure for data sharing due to its characteristics of complete decentralization, mass orientation, immediacy, and high security.

Zonghao Feng, Qiong Luo

Most public blockchain systems, exemplified by cryptocurrencies such as Ethereum and Monero, use memory-hard proof-of-work (PoW) algorithms in consensus protocols to maintain fair participation without a trusted third party. The memory hardness, or the amount of memory access, of these PoW algorithms is to prevent the dominance of custom-made hardware of massive computation units, in particular, application-specific integrated circuit (ASIC) and field-programmable gate array (FPGA) machines, in the system. However, it is unclear how effective these algorithms are on general-purpose processors. In this paper, we study the performance of representative memory-hard PoW algorithms on the CPU, the Graphics Processing Unit (GPU), and the Intel Knights Landing (KNL) processors. We first optimize each algorithm for individual processors, and then measure their performance with number of threads and memory size varied. Our experimental results show that (1) the GPU dominates the CPU and the KNL processors on each algorithm, (2) all algorithms scale well with number of threads on the CPU and KNL, and (3) the size of accessed memory area affects each algorithm differently. Based on these results, we recommend CryptoNight with scratchpads of different sizes as the most egalitarian PoW algorithm.

Marco Savi, Daniele Santoro, Katarzyna Di Meo, Daniele Pizzolli · 9 authors

This demonstration aims at showcasing an initial version of the DECENTER Brokerage Platform, which leverages an Ethereum blockchain to enable resource federation among different Fog Computing infrastructures. We consider a scenario where an Italian Infrastructure Provider wants to seamlessly extend its pool of resources to get access to an IP camera located in Korea, so that it can deploy an application to locally perform text recognition from a live video stream.

Prabhanjan Gururaj

Authenticating a person's identity has always been a challenge. While attempts are being made by government agencies to address this challenge, the citizens are being exposed to a new age problem of Identity management. The sharing of photocopies of identity cards in order to prove our identity is a common sight. From score-card to Aadhar-card, the details of our identity has reached many unauthorized hands during the years. In India the identity thefts accounts for 77% [1] of the fraud cases, and the threats are trending. Programs like e-Residency by Estonia[2], Bitnation using Ethereum[3] are being devised for an efficient Identity Management. Even the US Home Land Security is funding a research with an objective of “Design information security and privacy concepts on the Blockchain to support identity management capabilities that increase security and productivity while decreasing costs and security risks for the Homeland Security Enterprise (HSE).” [4] This paper will discuss the challenges specific to India around Identity Management, and the possible solution that the Distributed ledger, hashing algorithms and smart contracts can offer. The logic of hashing the personal data, and controlling the distribution of identity using public-private keys with Blockchain technology will be discussed in this paper.

N. Sundareswaran, S.P. Sasirekha, I. Joe Louis Paul, S. Balakrishnan · 5 authors

Know your customer or simply KYC is the process of validating and verifying the identity of its users and examining potential risks of illegal intentions for the business relationship. A few problems with the existing manual KYC process are that it is less secure, time consuming and costly. With the advent of Blockchain technology, its properties such as immutability, security, decentralization make them a good solution to such problems. While commercial solutions like “kyc-chain.com”, “KYC.legal” right to enable blockchain-based KYC verification, it provides a method for documents to be validated by a trusted participant in the network. In this work, Ethereum based Optimized KYC Blockchain system using symmetric AES encryption and LZ based compression mechanism is proposed. This system ensures transparency by distributed ledger, secured by cryptography, efficient by compression algorithm and overall optimized by blockchain features.

G. A. Pierro, Henrique Rocha, Roberto Tonelli, Sté́phane Ducasse

The Ethereum Blockchain is a distributed database that records all transactions and smart-contracts created on the platform. In Ethereum blockchain, the user needs to set a Gas price to get a transaction recorded. To have the transaction recorded, the Gas price has to be greater than or equal to the lowest Ethereum transaction fees. To help the users and smart contracts to set the right Gas price, the Gas Oracle categorizes the gas price into categories based on the interval of time the user might be willing to wait and for each of them suggests a gas price to set. The paper aims to verify the hypothesis that the predictions made by the EtherGasStation Oracle have a margin of error greater than the margin of error declared by it (2 %). We collected data in two-months time from the EthGasStation Oracle which predict the Gas Price every time that 100 blocks are added to the Ethereum Blockchain. In the same time frame, two-months, we also collected over 10 million transactions from a Transaction Pool. By cross-checking the data collected by the Transaction Pool and the Gas Oracle, the study revealed that the Gas Oracle fails more often than it advertises.

Meghali Nandi, Rajat Bhattacharjee, Amrit Kumar Jha, Ferdous Ahmed Barbhuiya

Land is an immovable and non-liquid asset having high value. The integrity and proper track of ownership/transfer records of land is a highly challenging task. As the ownership of land can constantly change over time and that too sometimes very frequently, it poses a daunting task of keeping elaborate and long ownership transfer records. The problem further escalates due to presence of fraudulent or incomplete registries which are very difficult to trace back through time. Thus ownership disputes in the system, lead to litigation running for years, leading to wastage of valuable time, energy and resource for solving these disputes. Most of the issues root from the problem of the current land registration systems being either having legacy paper document trails or from poorly kept non-transparent centralized systems. Fraudulent users may try to forge paper documents or modify electronic records to change the land ownership record. This paper proposes a secure record keeping mechanism that addresses these issues using a Blockchain based system which can create record for the physical assets into an immutable liquid Blockchain based token asset. This new block chain token asset can now be used to keep a digitally secured and selectively visible record of ownership, solving the mentioned issues. An implementation of this system has been done using Ethereum and the benchmark data shows that the transaction processing time of such a system is reasonably low thereby making it suitable for practical implementation.

Chun-Sheng Ke, Yean-Ru Chen

In recent years, many smart contracts on the ethereum platform are increasingly closer to our life. The existence of smart contract enables us to complete complicated transactions without depending on the third party. It should be not only fast, but also secure guaranteed. When the smart contract is requested to execute, the action is performed by ethereum virtual machine (EVM). If EVM occurs errors in the process of implementation, the contract execution result will also have mistaken. Therefore, ensuring the correctness of the EVM is very important. In this work, we propose a framework to formally verify EVM instruction implementations by model checking to check whether the instruction operation behaviors working on EVM is the same as the expected definitions in the ethereum yellow paper. In addition, we also define a set of interfaces specifically for EVM instruction verification to achieve the reusability of our proposed verification environment. The experimental results indicate that the formal verification method used in this work is more trustworthy than the conventional testing method. It can exactly capture the errors in the design which may be undetected by testing/simulation methods. The defined instructions are divided into 11 categories, and our work has completed to verify 7 categories, including 92 instructions of total 134, in 50 hours.

Uzair Bagadia, Jayant Bodkurwar, Jnanesh Bhat, Aparna Halbe

Crowdfunding is a form of fundraising in which we collect small amounts of money from a large number of people, which totals to a large amount. In short it is the pooling of large funds which are required for any projects or ideas. Over the years there has been a decrease in overall investment and had remained a complicated and a troubled domain due to lack of transparency and control by a central authorities being some of the primary reasons. There have been many attempts on solving this issue but none have been completely successful. Blockchain is a technology through which we can successfully achieve transparency in transactions up to some extent.

Qingzhao Zhang, Yizhuo Wang, Juanru Li, Siqi Ma

Smart contracts, programs running on blockchain systems, leverage diverse decentralized applications (DApps). Unfortunately, well-known smart contract platforms, Ethereum for example, face serious security problems. Exploits to contracts may cause enormous financial losses, which emphasize the importance of smart contract testing. However, current exploit generation tools have difficulty to solve hard constraints in execution paths and cannot simulate the blockchain behaviors very well. These problems cause a loss of coverage and accuracy of exploit generation. To overcome the problems, we design and implement EthPloit, a smart contract exploit generator based on fuzzing. EthPloit adopts static taint analysis to generate exploit-targeted transaction sequences, a dynamic seed strategy to pass hard constraints and an instrumented Ethereum Virtual Machine to simulate blockchain behaviors. We evaluate EthPloit on 45,308 smart contracts and discovered 554 exploitable contracts. EthPloit automatically generated 644 exploits without any false positive and 306 of them cannot be generated by previous exploit generation tools.

Yuyao Zhang, Siqi Ma, Juanru Li, Kailai Li · 6 authors

The immutable feature of blockchain determines that traditional security response mechanisms (e.g., code patching) must change to remedy insecure smart contracts. The only proper way to protect a smart contract is to fix potential risks in its code before it is deployed to the blockchain. However, existing tools for smart contract security analysis focus on the detection of bugs but seldom consider the code fix issues. Meanwhile, it is often time-consuming and error-prone for a developer to understand and fix flawed code manually. In this paper we propose SMARTSHIELD, a bytecode rectification system, to fix three typical security-related bugs (i.e., state changes after external calls, missing checks for out-of-bound arithmetic operations, and missing checks for failing external calls) in smart contracts automatically and help developers release secure contracts. Moreover, SMARTSHIELD guarantees that the rectified contract is not only immune to certain attacks but also gas-friendly (i.e., a slightly increase of gas cost). To evaluate the effectiveness and efficiency of SMARTSHIELD, we applied it to 28,621 real-world buggy contracts on Ethereum blockchain (as of January 2nd2019). Experiment results demonstrated that among 95,502 insecure cases in those contracts, 87,346 (91.5%) of them were automatically fixed by SMARTSHIELD. A following test with both program analysis and real-world exploits further testified that the rectified contracts were secure against common attacks. Moreover, the rectification only introduced a 0.2 % gas increment for each contract on average.

Sowmya Kudva, Renat Norderhaug, Shahriar Badsha, Shamik Sengupta · 5 authors

Although the current ride hailing services have revolutionized the transportation industry in today's world, they are extremely centralized. Central authority has all the control and maintains data about the users. Such platforms raise concerns about the service policies and data reliability. In case the central server faces data tampering or ransomware attacks, all the records of data is either lost or compromised. Blockchain has gained exceptional recognition while addressing aforementioned issues because of its decentralized data auditability, anonymity and immutability. Research on blockchain technology explores the possibility of implementing decentralized application in ride hailing service. Blockchain based ride hailing architecture gives us the opportunity to deviate from centralized platforms to decentralized ones. In this paper we propose our system PEBERS: Practical Ethereum Blockchain based Efficient Ride Hailing Service, in which we demonstrate how decentralized system based on consortium blockchain can be developed to keep track of ride data. In this context we explore smart contracts to build and deploy functionalities such as create ride, auto deposit transfer, cancel and complete ride methods of our decentralized ride hailing application. Our experiments show the driver smart contracts proposed in our system consume less Gas and hence prove that its an efficient system than many other existing systems with respect to the expenses of passengers and profitability of drivers. This is an effort towards providing smarter transportation for a society moving towards smart city concept.

Noama Fatima Samreen, Manar H. Alalfi

Ethereum Smart contracts use blockchain to transfer values among peers on networks without central agency. These programs are deployed on decentralized applications running on top of the blockchain consensus protocol to enable people to make agreements in a transparent and conflict-free environment. The security vulnerabilities within those smart contracts are a potential threat to the applications and have caused huge financial losses to their users. In this paper, we present a framework that combines static and dynamic analysis to detect Reentrancy vulnerabilities in Ethereum smart contracts. This framework generates an attacker contract based on the ABI specifications of smart contracts under test and analyzes the contract interaction to precisely report Reentrancy vulnerability. We conducted a preliminary evaluation of our proposed framework on 5 modified smart contracts from Etherscan and our framework was able to detect the Reentrancy vulnerability in all our modified contracts. Our framework analyzes smart contracts statically to identify potentially vulnerable functions and then uses dynamic analysis to precisely confirm Reentrancy vulnerability, thus achieving increased performance and reduced false positives.

Lodovica Marchesi, Michele Marchesi, Giuseppe Destefanis, Giulio Barabino · 5 authors

Blockchain technology is an emerging technology that allows new forms of decentralized architectures, designed to generate trust among users, without the intervention of mediators or knowledge between the parties. Since 2015, thanks to the introduction of Smart Contracts by Ethereum, it is possible to run programs on the blockchain, greatly extending the potential of this technology. The programming of Smart Contract, through the Solidity language is different from the traditional one. First of all, any action that requires to modify the blockchain costs gas, which corresponds to a fraction of the currency used by that given blockchain, and therefore to real money. Gas optimization is a unique challenge in this context and has obvious implications. This document aims to provide a set of design patterns and tips to help gas saving in developing Smart Contracts on Ethereum. The provided patterns are presented divided into five main categories, based on their features.

Amrita Jyoti, R. K. Chauhan

Before the invention of the various technologies, managing various activities and actions over the internet was achieved through a centralized server to guarantee valid data. With the expanding measure of accessible storage space and the quickening of data stream incited by the internet, a developing enthusiasm for data about the creation procedure and sources of information has developed. While this wide scope of use territories would profit by provenance data, the kind of provenance information, manipulation and querying facilities required vary from application to application. In this way, to discover the distinctions and similitudes between the different application and information model provenance needs and present a general plan for the arrangement of provenance. By characterizing this plan and applying it to existing work we plan to uncover open inquiries in the region of information provenance In this paper we survey the blockchain and provenance of the data in rice supplychain. We implement our proposed approach using smart contract which is to be deploy on ethereum blockchain network in rice supplychain to show the security and provenance of the data . We can track the progress of rice batch after each stage in blockchain and also discussed the need of provenance of assets in supplychain as it increase the trust of the customer