M. Sumathi, N. Vijayaraj, S. P. Raja, Venkatachalapathy Maharajan
HIGHLIGHTS The permissioned blockchain is used for resource allocation and monitoring. To reduce storage size, partial data is stored in the onchain blocks instead of entire data. The EU’s based Fixed and variable size resource allocation techniques are proposed.
Vladislav Amelin, Ernest Gatiyatullin, Nikita S. Romanov, Ratmir Samarkhanov · 6 authors
This paper introduces a function for blockchain performance evaluation as a black-box. The function runs the Solana blockchain test network with the only differences between the main network in a configuration file and the physical network to operate in. The black-box takes setup parameters as input, launches blockchain in a cloud, emulates artificial users’ activity, and gives two outputs–transactions per second (tps) and drop rate. By default, the setup has six most important integer parameters and a network with three computers in the cloud, while one can vary eighty-nine parameters, the number of computers in the network and use local computers via black-box configuration files. The applied problem is to maximize the tps under a zero drop rate constraint. The black-box, like real blockchains, uses network communication, so reproducibility is an essential part of the design. We also provide an optimization baseline, showing the non-trivial results’ reachability.
This paper shows the performance and scalability evaluation of different blockchain platform implementations. Hyperledger Iroha implementing YAC consensus, Sawtooth implementing PoET algorithm, and Hyperledger Fabric framework implementation. Performance evaluation and scalability assessment were done by varying different sets of parameters such as block size, transaction sending rate, network traffic distribution, and network size. Performance evaluation was done based on average transaction latency, network throughput, and transaction failure rate. Scalability was assessed based on changes in transaction latency and throughput with increasing network size. Test results let to study the impact of a particular parameter on the private blockchain network performance and show how they can be adjusted to improve performance.
The blockchain nexus with energy transactions in the distributed energy-trading arena successfully achieved a decentralized transaction and increased security. With the elimination of a third-party middle man, an electronic app is introduced to achieve decentralization and aid transactive communications. Observing the internet-of-things (IoT) intense protocols in the transactive communications amongst blockchain participants, however, leads to transaction time delay with associated uncertainty. This paper integrates the practical byzantine fault tolerance (pBFT) algorithm with the private Hyperledger Sawtooth blockchain network (P) to achieve a P-pBFT algorithm. The P-pBFT achieved a combined two-step transaction latency optimization (minimization) amongst the blockchain participants in the distributed energy generation (DEG) ecosystem. Through their combined feature extraction, further minimization is achieved by simulating the resulting transaction model derived from the integration. Subsequently, an optimization method is proposed to achieve the shortest transaction time given transaction constraints based on participants’ comfort. Thus, the ratio of node population to the transaction size and the choice of constraints can be regulated at the participants’ convenience to achieve minimum transaction time. Hence, the benefit of deciding the transaction time is achieved thereby eliminating the undesired characteristic uncertainty.
The field of blockchain and cryptocurrencies can be both difficult to grasp and improve upon, which makes aids that can assist in these tasks very useful. SpartanGold is a simplified blockchain-based cryptocurrency created at San Jose State University as a learning aid for blockchain and cryptocurrencies. In its current state, it closely resembles Bitcoin, and it is also easily expandable to implement other features. This project extends SpartanGold with a virtual machine resembling the Ethereum Virtual Machine. Implementing this feature results in SpartanGold having Ethereum- related features, which would allow the cryptocurrency to both be a helpful learning aid for Ethereum and be able to solve interesting blockchain problems associated with virtual machines and smart contracts. Using my virtual machine implementation, I was able to produce a simplified token that resembles Ethereum tokens and works with SpartanGold. This token demonstrates the SpartanGold Virtual Machine’s usefulness in simulating smart contracts of real world interest. Going forward, developers can experiment with the SpartanGold Virtual Machine to test out new ideas without dealing with the full complexity of the Ethereum Virtual Machine.
When the Ethereum blockchain was first built, there was no chainId in the blocks. The concept of chainId was introduced after a DAO attack in 2016 that resulted in 3.6 million ethers stolen and made Ethereum blockchain to fork into two blockchains, that is, Ethereum mainnet (ETH) and Ethereum Classic. In this chapter, a crosschain id service project is developed from specification, architecture, design, smart contract coding, to Web client implementations.
The research on the governing blockchain by blockchain supervision system is an important development trend of blockchain technology. In this system there is a supervisory blockchain managing and governing the supervised blockchain based on blockchain technology, results in a uniquely cross-blockchain demand to consensus mechanism for solving the trust problem between supervisory blockchain and supervised blockchain. To solve this problem, this paper proposes a cross-blockchain consensus mechanism based on smart contract and a set of smart contracts endorse the cross-blockchain consensus. New consensus mechanism called Proof-of-Endorse-Contracts (PoEC) consensus, which firstly transfers the consensus reached in supervisory blockchain to supervised blockchain by supervisory nodes, then packages the supervisory block in supervisory blockchain and transmits it to the smart contract deployed in the supervised blockchain, finally miners in supervised blockchain will execute and package the new block according to the status of the smart contract. The core part of the consensus mechanism is Endorse Contracts which designed and implemented by us and verified the effectiveness through experiments. PoEC consensus mechanism and Endorse Contracts support the supervised blockchain to join the governing blockchain by blockchain system without changing the original consensus mechanism, which has the advantages of low cost, high scalability and being able to cross-blockchain. This paper proves that our method can provide a feasible cross-blockchain governance scheme for the field of blockchain governance.
The four components of blockchain that working together create its enormous potential to alleviate economic inefficiencies in our current system are distributed ledgers, privacy preservation, algorithms for distributed systems consensus, and smart contracts.
In this paper, we have proposed the intimate environment of multiblockchain optimization algorithm using big data inquiry to mend the effectiveness of association query handling among numerous multihoming blockchains by implementing the big data system. This technique adds semantic evidences to the old‐styled multiblockchain prototype and constructs a semantic model of multiblockchain that delivers a foundation for linking queries among the various blockchain multihoming system in big data. On the base of this model, distributed databases have index arrangement, and a linking index arrangement is proposed among the numerous blockchains, with several attributes linked to these blockchains employed to improve the efficacy of linking calculation. Besides, the communication cost is d for data communication. On this foundation, a multichain linking enquiry algorithm based on optimization is anticipated to progress the productivity of multiblockchain connection queries. To conclude, two genuine big data community sets of data are used to conduct experiments on. The associating index arrangement among blockchains is unchanging and is equated with the old‐styled direct linking inquiry operation. The multiblockchain linking query method of optimization shortens the probe processing procedure. It acquires the query outcomes directly by retrieving the linking index, sinking the local calculating ability, system overhead, and illuminating query efficacy.
In recent years, blockchain technology has been applied in the educational domain because of its salient advantages, i.e., transparency, decentralization, and immutability. Available systems typically use public blockchain networks such as Ethereum and Bitcoin to store learning results. However, the cost of writing data on these networks is significant, making educational institutions limit data sent to the target network, typically containing only hash codes of the issued certificates. In this paper, we present a system based on a private blockchain network for lifelong learning data authentication and management named B4E (Blockchain For Education). B4E stores not only certificates but also learners’ training data such as transcripts and educational programs in order to create a complete record of the lifelong education of each user and verify certificates that they have obtained. As a result, B4E can address two types of fake certificates, i.e., certificates printed by unlawful organizations and certificates issued by educational institutions for learners who have not met the training requirements. In addition, B4E is designed to allow all participants to easily deploy software packages to manage, share, and check stored information without depending on a single point of access. As such, the system enhances the transparency and reliability of the stored data. Our experiments show that B4E meets expectations for deployment in reality.
In addition to being a game-changer for the cryptocurrency business, Blockchain was also a catalyst for the fast rise of certain Distributed Ledger Technologies (DLTs). An important aspect of a DLT system's design is a consensus mechanism, which ensures that almost all interviewees agreed on the integrity of the data. As a result, a broad variety of consensus protocols have been developed, each with a distinct notion and property (e.g., reduced energy usage, greater scalability). When moving from one blockchain network to another, the main criteria for consensus mechanisms typically vary dramatically, so there is no universal protocol. As a result, choosing the best consensus mechanism for a certain DLT system is critical, but also difficult, since experts must balance competing demands. MCDM approaches are used in this research to provide an approach for choosing the best consensus procedures based on criteria, objectives, and other needs. A genuine bike-rental application is used to show the technology's potential, as well as the preferred consensus mechanisms for 3 of the most popular kinds of current blockchain systems. To top it all off, the information and technologies gathered are openly accessible for anybody to use, allowing for maximum replication and future improvement.
In the previous chapter, we discussed Ethereum architecture, ecosystem, and decentralized applications. We also described development tools such as MetaMask, Remix, Truffle, and Geth. In this chapter, we are going to learn detailed Solidity programming skills for smart contract and decentralized application development.
Increasing numbers of users are outsourcing data to the cloud, but data integrity is an important issue. Due to the decentralization and immutability of blockchain, more and more researchers tend to use blockchain to replace third-party auditors. This paper proposes a data integrity system based on blockchain expansion technology that aims to solve the problem of high cost for blockchain network maintenance and for user creation of new blocks caused by the rapid growth of blocks in the data integrity audit scheme of existing blockchain technology. Users and cloud service providers (CSP) deploy smart contracts on the main chain and sub-chains. Intensive and frequent computing work is transferred to the sub-chain for completion, and the computation results of the sub-chain are submitted to the main chain periodically or when needed to ensure its finality. The concept of non-interactive audit is introduced to avoid affecting user experience due to the communication with the CSP during the audit process. In order to ensure data security, a reward pool mechanism is introduced. Comprehensive analysis from aspects such as storage, batch auditing and data consistency proves the correctness of the scheme. Experiments on the Ethereum blockchain platform demonstrate that this scheme can effectively reduce storage and computational overhead.
Blockchain has been regarded as a trusted carrier for distributed data storage. With large volumes of valuable data stored on blockchain, data query has become a major requirement. However, the existing blockchains do not provide efficient query functionality because of their deep-rooted chain structure. Blockchain database is a new direction that constructs index on top of blockchain to provide rich query functionalities. The existing works are either insecure because the query process separates from the blockchain consensus, or inscalable because all the data needs to be stored in the block. In this paper, we propose a novel semantic blockchain database called MSTDB. We design a hybrid on/off chain blockchain storage architecture in which the majority of blockchain storage is offloaded to the off-chain storage and a novel index structure named Merkle Semantic Trie (MST) is designed to be a secure and semantic bridge between on- and off-chain. Based on MST, MSTDB provides a variety of semantic query functions including multi-keyword query, range query, Top-K query, and cross-chain query. To improve the performance further, we design some index compression and query preprocessing techniques for MSTDB. Extensive experiments demonstrate the effectiveness and efficiency of our blockchain database.
Marios Touloupou, Marinos Themistocleous, Elias Iosif, Klitos Christodoulou
Blockchain is a disruptive technology that focuses on the safe exchange of data between several distributed applications. Despite its widespread adoption, there are areas that require further research towards the understanding of their performance characteristics. In addition, consensus algorithms, a vital part of blockchain, require a more comprehensive understanding of their technical principles and characteristics. Along with the design of different types of consensus algorithms, several challenges, such as system scalability and power consumption, have been raised. Therefore, more comprehensive research is needed to investigate the degree to which consensus algorithms are built and how they perform. To this end, this study extends the body of knowledge and contributes towards the assessment of blockchain protocol performance. We present a comprehensive taxonomy of selected studies on blockchain performance, identifying similarities and differences while attempting to identify existing work on simulators and benchmarking frameworks that aim to explore the performance of blockchain-enabled consensus algorithms.