Search

To address the high throughput and resistance to Byzantine node attacks in the microgrid trading scenario of consortium chains, this paper proposed a multi-leader Byzantine fault tolerance consensus algorithm based on Raft, named MLBRaft. The algorithm first utilized the VRF to select a group of leader nodes, increasing throughput by allowing multiple leaders to submit blocks in parallel. A coordinator role was then introduced, responsible for the election and management of leaders and system consensus. During the block replication process between leaders and followers, the consensus process of the practical Byzantine fault tolerance (PBFT) algorithm was integrated and simplified to achieve the Byzantine resilience of this algorithm. Experimental results show that, under a large-scale network node environment, compared to the Raft algorithm, this algorithm improves throughput and consensus efficiency at the cost of some communication overhead. Compared to the PBFT algorithm, this algorithm enhances Byzantine fault tolerance and reduces communication overhead. In summary, this algorithm can effectively ensure the timeliness and security of alliance chain microgrid transactions. [ABSTRACT FROM AUTHOR]

Summary Duc to the outbreak of the Covid-19 epidemic around the world in 2020 and the huge impact on the global supply chain, small and medium-size enterprises (SMEs) are facing huge pressure to survive and the financing conditions for SMEs are is particularly difficult. Once the cashflow chain is broken. SMEs may face bankruptcy, thus endangering the survival of large and medium-sized firms, and may even lead to the collapse of the whole supply chain. In the long term. the financing constraints of SMEs have been a problem that has plagued many countries around the world, including developed countries, and have not been effectively solved. Supply chain finance is one of the effective methods to alleviate financing constraints for firms. However, traditional supply chain finance has many shortcomings, such as information asymmetry, transaction forgeries, difficult credit evaluation, low business efficiencies. and inconvenient regulation of collateral. This paper utilizes the excellent. characteristics of blockchain to empower traditional supply chain finance, which can effectively resolve the shortcomings of traditional supply chain finance and help alleviate the financing constraints of firms. The research results not only can provide a new way to effectively solve the financing constraints for SMEs, but also can make a positive contribution to the comprehensive development of the digital economy and society. Currently, most literatures mainly discuss the basic characteristics, development models, business optimizations, and evolutionary games of blockchain-based supply chain finance. This paper firstly indicates the reasons for choosing the consortium blockchain and illustrates the network constructions of the supply chain finance system based on consortium blockchain. And then we initially analyze the operating mechanism of the system through adopting PBFT algorithm to achieve consistent consensus. We finally show the application scenarios of accounts receivable financing in our system. The main results we found are as follows. Firstly, because of the outstanding performances of the consortium blockchain, such as partial decentralization. consensus trust, tamper-proof, traceability, smart contract, privacy and security, it is much more suitable for the consortium blockchain rather than a public blockchain or private blockchain to build up the supply chain finance system. Secondly, the existing literatures of blockchain-based supply chain finance are not abundant and there are very rare researches about its internal logicality and operating mechanisms. Through carrying out the processes of selecting the master node, packaging data. building new blocks and verifying messages, the PBFT algorithm can achieve consistent consensus among all the nodes, which is the essential key to the operating mechanism of the supply chain finance system based on consortium blockchain. Meanwhile, this paper optimize the "requests pool" in the consensus processes and propose the data structures of the consensus algorithm. We hope to provide the theoretical references for the R&D and applications of the blockchain-based supply chain finance system for banks and firms. Thirdly, from the three perspectives of business processes, data adding to blockchain and financing performances. this paper discusses how banks and firms utilize the blockchain-based supply chain system to implement the financing businesses of accounts receivable. Compared with the common trade finance and the traditional supply chain finance, our system could be able to significantly shorten corporate financing time, reduce corporate loan interest rate and expand corporate loan volume. Our research is not only conducive to solving the corporate financing difficulties. especially for small and medium-sized enterprises, but also provides theoretical foundations and practical guidance for firms and banks to exploit and develop the supply chain finance system based on consortium blockchain. [ABSTRACT FROM AUTHOR]

Currently, in the blockchain-based distributed microgrid trading system, there are some problems, such as low throughput, high delay, and a high communication overhead. To this end, an improved Practical Byzantine Fault Tolerance (PBFT) algorithm (CE-PBFT) suitable for microgrid power trading is proposed. First, a node credit value calculation model is introduced, and nodes are divided into consensus, supervisory, and propagation nodes according to their credit values, forming a hierarchical network structure to ensure the efficiency and reliability of consensus. Secondly, the consensus process is optimized by adopting a segmented consensus mechanism. This approach calculates the consensus rounds for nodes and selects the methods for node-type switching and consensus based on these calculations, reaching dynamic changes in node states and credit values, effectively reducing the communication overhead of node consensus. Finally, the experiments show that compared with the IMPBFT and PBFT algorithms, the CE-PBFT algorithm has better performance in throughput, delay, and communication overhead, with a 22% higher average throughput and 15% lower average delay than the IMPBFT algorithm and a 118% higher average throughput and 87% lower average delay than the PBFT algorithm. [ABSTRACT FROM AUTHOR]

In response to the problems of random selection of primary nodes, high communication complexity, and low consensus efficiency in the current consensus mechanism for intellectual property transactions, a Practical Byzantine Fault Tolerance (PBFT) consensus algorithm based on the Affinity-Propagation (AP) clustering algorithm, termed AP-PBFT, is proposed. Firstly, the election strategy of the leader node is constructed based on the reputation mechanism; the reward and punishment mechanism is designed to achieve the dynamic adjustment of the reputation value of the nodes in the PBFT consensus process, and the number of votes among the nodes is introduced to determine the node's reputation value in collaboration with the reward and punishment mechanism to guarantee the precise ordering of the nodes. Secondly, nodes with high reputation values are selected as cluster centers to run the AP clustering algorithm, and clustering groups of knowledge property transaction nodes are constructed based on responsibility and availability. Finally, the three-stage consensus process of the PBFT consensus algorithm is optimized, and the consensus task is decomposed into two layers: the intra-consensus group and the inter-leader node group, reducing the communication complexity of transaction data in the blockchain. Experimental findings indicate a significant performance improvement of the algorithm over the PBFT consensus algorithm in communication complexity, throughput, and consensus efficiency in the simulation environment of multiple types of transactions in intellectual property transactions, including different types of large-scale transaction scenarios, such as purchases, sales, licenses, and transfers. [ABSTRACT FROM AUTHOR]

In response to the shortcomings of the consensus algorithm for intellectual property transactions, such as high communication overhead, random primary node selection, and prolonged consensus time, a Practical Byzantine Fault Tolerance (PBFT) improvement algorithm based on Divisive Analysis (DIANA) D-PBFT algorithm is proposed. Firstly, the algorithm adopts the hierarchical clustering mechanism of DIANA to cluster nodes based on similarity, enhancing node partition accuracy and reducing the number of participating consensus nodes. Secondly, it designs a reward and punishment system based on node ranking, to achieve consistency between node status and permissions, timely evaluation, and feedback on node behaviours, thereby enhancing node enthusiasm. Then, the election method of the primary node is improved by constructing proxy and alternate nodes and adopting a majority voting strategy to achieve the selection and reliability of the primary node. Finally, the consistency protocol is optimised to perform consensus once within the cluster and once between all primary nodes, to ensure the accuracy of the consensus results. Experimental results demonstrate that the D-PBFT algorithm shows a better performance, in terms of communication complexity, throughput, and latency. [ABSTRACT FROM AUTHOR]

Copyright of Journal of South-Central Minzu University (Natural Science Edition) is the property of Journal of South-Central Minzu University (Natural Science Edition) Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In response to challenges posed by the Practical Byzantine Fault Tolerance (PBFT) consensus algorithm, where all nodes are involved in the consensus process, issues such as high communication overhead in the three-phase procedure, random selection of master nodes, and the absence of reward and penalty mechanisms are addressed. This leads to the proposal of a Speculative Practical Byzantine Fault Tolerance (SP-PBFT) consensus algorithm based on a node evaluation mechanism for speculative grouping. Firstly, the consensus protocol was optimized, and a timeout mechanism was proposed to divide the consensus process into an optimistic mode and a pessimistic mode, which reduced the communication overhead under the premise of resisting Byzantine node attacks. Secondly, a node evaluation mechanism was proposed to calculate the node reputation value according to the node's historical behavior and give the corresponding reward or punishment, which reduced the possibility of malicious nodes participating in the consensus process. Finally, the Fibonacci grouping mechanism was used to reduce the number of nodes participating in the consensus process, fundamentally improving the consensus efficiency, avoiding the problem of centralization of the consensus process caused by the cumulative reputation value of nodes, and improving the enthusiasm of consensus nodes. Simulation experiments using Docker containers to simulate multiple nodes show that the SP-PBFT consensus algorithm proposed in this paper has better performance than the PBFT consensus algorithm and other improved algorithms in terms of consensus delay, throughput, fault tolerance and communication complexity. [ABSTRACT FROM AUTHOR]

In response to the problems of the practical Byzantine fault-tolerant algorithm (PBFT), such as random selection of master nodes and poor scalability, a CART-based PBFT optimization algorithm is proposed, namely the C-PBFT algorithm. First, the introduction of weighted impurity variables improves the CART algorithm, overcomes the mutual influence of attributes between nodes, and improves the classification accuracy. Secondly, through the point grouping mechanism, the nodes are divided into three types: consensus nodes, candidate nodes, and alternate nodes, which are dynamically adjusted based on node behavior to ensure the reliability of consensus nodes. Finally, the voting weight is introduced into the consensus node, and the consensus is reached by using the voting weight exceeding the threshold, which reduces the message transmission in the blockchain network and improves the efficiency of the algorithm operation. The experimental results show that the improved consensus algorithm has better performance in terms of delay, throughput, and fault tolerance and reduces the frequent switching of views caused by the failure of the master node. [ABSTRACT FROM AUTHOR]

Aiming at the problems of centralized storage, low sharing efficiency, and the security and privacy of traditional medical data, a medical data storage model based on a consortium chain is proposed. First, the Distance algorithm is designed based on the geographical relationship of nodes, which reduces the amount of communication between nodes, improves the communication efficiency between A nodes, and ensures the efficiency and reliability of grouping. Second, the dynamic election is combined with the Distance algorithm to design the election strategy of the primary node, which realizes the scientific and reasonable ranking of the medical nodes, improves the reliability of the selection of the primary node, and ensures the efficiency of the medical nodes in the alliance chain to quickly reach consensus when the medical data are uploaded to the chain. Finally, the model designs a method of information separation, which combines the distributed database IPFS (InterPlanetary File System) with the blockchain, which greatly reduces the pressure of medical data storage in the blockchain and improves the operation efficiency. The experimental results show that the medical data storage model can effectively improve the problem of the sharp increase in the amount of communication between medical nodes in the network and reduce the impact of malicious consensus nodes. [ABSTRACT FROM AUTHOR]

Aiming at the problem that sybil attack has great harm to block chain technology,a method to improve the PBFT algorithm in the alliance chain to defend against sybil attacks was proposed.Firstly,using the idea of consensus algorithm based on proof of rights and interests,a reputation model was established,the reputation value of each node accorded to the behavior of each node in the consensus process was calculated,and different discourse rights accorded to the size of the reputation value was given.Then pre-commit phase was added to the PBFT algorithm to reduce the number of communication between nodes.The solution through formal analysis and reasoning and security testing shows that the improved PBFT algorithm can not only effectively defend against sybil attacks in the blockchain,but also make the performance of the blockchain system in terms of TPS and block generation delay.

Aiming at problems of data loss and tampering during data transmission and storage of mine Internet of things(IoT), blockchain technology was applied to data transmission and storage of mine IoT. Mine private blockchain architecture with data layer, transmission layer and consensus layer as core was constructed. Protection schemes for data transmission and storage of mine IoT based on consensus module and data block were designed. Practical Byzantine fault tolerance algorithm was used to design data consensus process. Consensus module was set up between every two nodes of distributed structured P2P network and P2P protocol was optimized to achieve mine data security consensus. The test results show that application of private blockchain guarantees accurate transmission and reliable storage of mine IoT data.

Consortium chain is the main application form of blockchain technology in the actual industry, and its consensus mechanism mostly adopts the practical Byzantine fault-tolerant algorithm (PBFT). However, if the number of nodes is too large the success rate and efficiency of consensus will lower, and have scalability problems. Therefore, this paper proposed a Byzantine fault-tolerant consensus algorithm NAC-PBFT based on network self clustering. Using the known information of network structure and system node in industry application, the seed node designated in the audit node of consortium chain, and taken as the center and self clustered into several groups. It elected the agents by optimizing the practical Byzantine fault-tolerant algorithm in the group, and the agents in each group completed the global consensus. During the intra group election, the credibility index was defined to measure the node, and it was used as the standard for selecting candidate agents to ensure that the agents selected each time were in good condition. Through the system analysis and performance test, NAC-PBFT algorithm can effectively reduce the amount of information, has better performance in consensus time and system throughput index, and has better scalability. [ABSTRACT FROM AUTHOR]

Copyright of Journal on Communication / Tongxin Xuebao is the property of Journal on Communications Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Mine Automation is the property of Industry & Mine Automation Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

With the introduction of edge computing into the field of Internet of Things (IoT), the Cognitive Internet of Things (CIoT) has emerged as the next-generation solution for trust and intelligent reasoning in the IoT. That also puts blockchain, with its unique consensus mechanism, transparency and trustworthiness, on the stage of IoT applications. At present, not much research is focused on blockchain's application in CIoT, whose development is to a large extent restricted by the inefficiency of the consensus algorithm. Considering the characteristics of CIoT, a multi-stage consensus algorithm of EIoT-PBFT is proposed on the basis of PBFT algorithm, which includes the Grouping stage, Scoring stage and Consensus reaching stage. EIoT-PBFT meets the IoT edge computing setup by adopting a two-phase improved PBFT algorithm and a scoring mechanism based on both location and reputation, thus achieving a great increase in consensus efficiency. Evaluation results show that EIoT-PBFT takes 36.4% less time than PBFT for a single consensus, and the performance remains stable over the 2500 node configurations we set up. Moreover, at a scale of 1000 nodes, the number of edge nodes to be configured to reduce the number of system communications by 90% compared to the PBFT algorithm is only 5, making blockchain more customized for CIoT settings. [ABSTRACT FROM AUTHOR]