Benchmarking and evaluation of blockchain systems and applications

Ph. D. ThesisIn the past ten years, we have witnessed the evolution of cryptocurrencies. With market capitalizations of $189bn and$19bn respectively in September 2019, Bitcoin and Ethereum are the world’s most successful cryptocurrencies. Blockchain, which is a public ledger that is immutable, is the main innovation behind these cryptocurrencies. In Bitcoin, the blockchain is introduced to exchange and trade a single asset, whereas in Ethereum it is used to store and execute a smart contract with a Turing Complete Machine. Ethereum’s Gas mechanism, which charges the execution of each operation code, ensures the termination of smart contracts that run in the EVM (Ethereum Virtual Machine) and to compensate the computational usage. Thus, the gas awarded should be proportional to the required computational, to ensure aligned incentives and to avoid denial of services attacks. Currently, in Ethereum, gas awarded is set statically for each opcode in the smart contract, but it is unknown whether these values are correct for various computer architectures. Therefore, in this thesis, firstly, we propose a benchmark approach to measure the CPU times required to deploy and execute real smart contracts obtained from the Ethereum blockchain and compare it with the gas award in the PyEthApp client running over a single machine. The result of our benchmark study shows the collected Gas is not always proportional to the invested CPU for both deploying and executing smart contracts. Secondly, we focus more in-depth on the operational codes (opcodes) and conduct a benchmark study to investigate whether the Gas cost set by Ethereum for each opcode is aligned with the CPU usage. The experiments are conducted on three Ethereum clients running over different hardware platforms and operating systems. The results show that the Gas cost is not always proportional to CPU usage. Finally, we implement and analyze the performance of blockchain and smart contract technologies in different domains, in particular cloud computing and distributed database management systems. In cloud computing, we create the first smart contract implementation that achieves both verifiability and cost-efficiency using any two client providers. For distributed database management systems, we implement the first smart contract-based two-phase commit protocol in Ethereum’s blockchain. For both systems, we investigate the cost, the performance and trade-offs in the blockchain. We tested the implementations of these systems on Ethereum’s official, test and private networks. We also provide a financial and computational analysis of their costs

Betrayal, Distrust, and Rationality: Smart Counter-Collusion Contracts for Verifiable Cloud Computing

Cloud computing has become an irreversible trend. Together comes the pressing need for verifiability, to assure the client the correctness of computation outsourced to the cloud. Existing verifiable computation techniques all have a high overhead, thus if being deployed in the clouds, would render cloud computing more expensive than the on-premises counterpart. To achieve verifiability at a reasonable cost, we leverage game theory and propose a smart contract based solution. In a nutshell, a client lets two clouds compute the same task, and uses smart contracts to stimulate tension, betrayal and distrust between the clouds, so that rational clouds will not collude and cheat. In the absence of collusion, verification of correctness can be done easily by crosschecking the results from the two clouds. We provide a formal analysis of the games induced by the contracts, and prove that the contracts will be effective under certain reasonable assumptions. By resorting to game theory and smart contracts, we are able to avoid heavy cryptographic protocols. The client only needs to pay two clouds to compute in the clear, and a small transaction fee to use the smart contracts. We also conducted a feasibility study that involves implementing the contracts in Solidity and running them on the official Ethereum network.Comment: Published in ACM CCS 2017, this is the full version with all appendice

A Blockchain-Based Data Authentication Algorithm for Secure Information Sharing in Internet of Vehicles

Secure communication between connected electric vehicles is critical for realizing the full potential of the Internet of Vehicles. However, the authentication and security of the information shared between vehicles remains a major challenge. In this work, we propose a blockchain-based data authentication algorithm to enable secure information sharing between electric vehicles. Our algorithm leverages the distributed ledger and consensus mechanism of blockchain technology to overcome limitations of traditional public key infrastructure schemes for large-scale vehicle networks. Each electric vehicle has a unique key pair and address on the blockchain network. Vehicles generate digital signatures using their private keys to share data, while recipients verify the signatures using corresponding public keys for authentication. Experimental results demonstrate that the proposed algorithm achieves high authentication success rates with acceptable latency and computation overhead. The algorithm provides benefits like decentralization, transparency and non-repudiation compared to existing approaches. Our work indicates the potential of blockchain to enhance security, trust and cooperation in Internet of Vehicles applications

Slither code analysis.

As the use of digital subscription services like electronic tickets (E-ticketing) has grown in the age of e-commerce, so too have instances of copyright and violation. Because it is dependent on the centralized authority administration of authoritative institutions, the traditional E-ticketing system has a significant cost associated with it. Blockchain, which is a distributed system, has the characteristics of decentralization, anonymity, auditability, security, and persistency. These attributes allow it to address the problems that are currently being experienced by the E-ticketing system. In this study, we present a framework for E-ticketing that makes use of blockchain technology. The blockchain-based electronic ticketing model eliminates the involvement of third parties while also lowering the potential of data leaks and improving users’ levels of privacy. This is accomplished by separating the credential information of users from the financial transactions. In the meanwhile, a blockchain implementation of the existing E-ticketing architecture has the potential to improve throughput, reduce the amount of redundant work, and boost the efficiency of consensus. An examination of the experimental data shows that the framework has a number of advantages, some of which are a high throughput, flexible scalability, and efficient ticket holding times.</div

BlockTicket main entities and their interaction with the blockchain.

BlockTicket main entities and their interaction with the blockchain.</p

Performance comparison of BlockTick and [44].

As the use of digital subscription services like electronic tickets (E-ticketing) has grown in the age of e-commerce, so too have instances of copyright and violation. Because it is dependent on the centralized authority administration of authoritative institutions, the traditional E-ticketing system has a significant cost associated with it. Blockchain, which is a distributed system, has the characteristics of decentralization, anonymity, auditability, security, and persistency. These attributes allow it to address the problems that are currently being experienced by the E-ticketing system. In this study, we present a framework for E-ticketing that makes use of blockchain technology. The blockchain-based electronic ticketing model eliminates the involvement of third parties while also lowering the potential of data leaks and improving users’ levels of privacy. This is accomplished by separating the credential information of users from the financial transactions. In the meanwhile, a blockchain implementation of the existing E-ticketing architecture has the potential to improve throughput, reduce the amount of redundant work, and boost the efficiency of consensus. An examination of the experimental data shows that the framework has a number of advantages, some of which are a high throughput, flexible scalability, and efficient ticket holding times.</div

BlockTicket sequence diagram.

As the use of digital subscription services like electronic tickets (E-ticketing) has grown in the age of e-commerce, so too have instances of copyright and violation. Because it is dependent on the centralized authority administration of authoritative institutions, the traditional E-ticketing system has a significant cost associated with it. Blockchain, which is a distributed system, has the characteristics of decentralization, anonymity, auditability, security, and persistency. These attributes allow it to address the problems that are currently being experienced by the E-ticketing system. In this study, we present a framework for E-ticketing that makes use of blockchain technology. The blockchain-based electronic ticketing model eliminates the involvement of third parties while also lowering the potential of data leaks and improving users’ levels of privacy. This is accomplished by separating the credential information of users from the financial transactions. In the meanwhile, a blockchain implementation of the existing E-ticketing architecture has the potential to improve throughput, reduce the amount of redundant work, and boost the efficiency of consensus. An examination of the experimental data shows that the framework has a number of advantages, some of which are a high throughput, flexible scalability, and efficient ticket holding times.</div

BlockTicket flow diagram.

As the use of digital subscription services like electronic tickets (E-ticketing) has grown in the age of e-commerce, so too have instances of copyright and violation. Because it is dependent on the centralized authority administration of authoritative institutions, the traditional E-ticketing system has a significant cost associated with it. Blockchain, which is a distributed system, has the characteristics of decentralization, anonymity, auditability, security, and persistency. These attributes allow it to address the problems that are currently being experienced by the E-ticketing system. In this study, we present a framework for E-ticketing that makes use of blockchain technology. The blockchain-based electronic ticketing model eliminates the involvement of third parties while also lowering the potential of data leaks and improving users’ levels of privacy. This is accomplished by separating the credential information of users from the financial transactions. In the meanwhile, a blockchain implementation of the existing E-ticketing architecture has the potential to improve throughput, reduce the amount of redundant work, and boost the efficiency of consensus. An examination of the experimental data shows that the framework has a number of advantages, some of which are a high throughput, flexible scalability, and efficient ticket holding times.</div

Comparison of the proposed framework and the existing work between 2020 and 2022.

Comparison of the proposed framework and the existing work between 2020 and 2022.</p

A Novel Fuzzy Logic-Based Scheme for Malicious Node Eviction in a Vehicular Ad Hoc Network

Securing communication in vehicular ad hoc networks (VANETs) is hampered by numerous constraints, making it more difficult. First, traditional security schemes cannot be directly applied in VANET because they consider fixed topology. Second, VANET enables dynamic spectrum access where nodes constantly change frequencies due to their high degree of mobility, resulting in severe consequences on network performance. Third, an effective security scheme in VANET needs local and continual knowledge of nodes. Last, the presence of malicious nodes and their misbehaving activities impair the safety of the drivers since they might alter the content of the sent safety alerts. With these constraints in mind, this paper presents a unique security strategy that utilizes node behaviour during message exchange as a security metric to address these issues. Through the message alert exchange phase, node behaviour is measured through the fuzzy logic framework to generate a rank for each node called trust level (BL), which describes the node’s reliability in exchanging safety messages correctly. Moreover, all messages in VANET are encrypted using the existing cryptography techniques. The proposed scheme is developed to enhance communication security in VANET, minimize the effects of malicious nodes, and improve resource utilization in VANET. Evaluation of the proposed scheme shows that it improves the performance of VANET in terms of end-to-end delay, packet delivery ratio, and packet loss ratio. According to the results, our scheme improves throughput by up to 23% and reduces end-to-end delay by up to 60%