Improved PBFT Consensus Algorithm Based on Node Role Division

The PBFT (Practical Byzantine Fault Tolerance, PBFT) consensus algorithm, which addressed the issue of malicious nodes sending error messages to disrupt the system operation in distributed systems, was challenging to support massive network nodes, the common participation over all nodes in the consensus mechanism would lead to increased communication complexity, and the arbitrary selection of master nodes would also lead to inefficient consensus. This paper offered a PBFT consensus method (Role Division-based Practical Byzantine Fault Tolerance, RD-PBFT) to address the above problems based on node role division. First, the nodes in the system voted with each other to divide the high reputation group and low reputation group, and determined the starting reputation value of the nodes. Then, the mobile node in the group was divided into roles according to the high reputation value, and a total of three roles were divided into consensus node, backup node, and supervisory node to reduce the number of nodes involved in the consensus process and reduced the complexity of communication. In addition, an adaptive method was used to select the master nodes in the consensus process, and an integer value was introduced to ensure the unpredictability and equality of the master node selection. Experimentally, it was verified that the algorithm has lower communication complexity and better decentralization characteristics compared with the PBFT consensus algorithm, which improved the efficiency of consensus.

基于区块链的互联网医院云药房平台设计和实践

目的应用区块链技术,构建互联网医院云药房处方流转可信安全互通机制,实现信息可信、过程可追溯,保障用药安全。方法通过对云药房的处方流转风险与问题分析,利用区块链去中心化、智能合约、防篡改和可追溯等技术特性,针对问题给出解决问题的技术方案。结果提出基于区块链的互联网医院云药房平台管理架构,建设信息互联互通、处方信息认证、处方流转全程追溯机制,形成互联网医院电子处方流转多主体间透明、对等、可信的合作范式。结论实现互联网医院处方流转过程的规范化管理,确保互联网电子处方信息安全流通,保障患者用药安全。

A Review: Consensus Algorithms on Blockchain

Blockchain is a distributed public ledger that keeps track of all transactions that have ever taken place in the system. As a distributed ledger, a consensus mechanism is required to ensure all the transaction functions properly. In order to reach a consensus, it is critical to emphasize the importance of performance and efficiency. The use of the right consensus algorithm will significantly improve the efficiency of a blockchain application. This paper reviewed several types of consensus algorithms used in blockchain and discusses the idea of a new consensus algorithm that can improve the performance of consortium blockchain.

Blockchain-based verifiable computation with optimized resource allocation

Nowadays,the data that users need to calculate and process increases sharply,however,ordinary users usually lack the required capability.Therefore,resorting to outsourcing computation,they can delegate computing tasks to high-performance nodes over the network to meet their needs.In order to ensure the correctness of outsourcing computations,a verifiable computing scheme based on the blockchain smart contract is proposed,where the primary node and the replica nodes complete the task calculation and verification respectively,and reach a final consensus on the results.Moreover,the computing resources and energy consumption of each node to make the consensus are analyzed,based on which an optimization of resources allocation is proposed to maximize the transaction throughput.The simulation results show the effectiveness of the proposed scheme built on distributed consensus and also the throughput improvement by optimizing.

Design of improved PBFT algorithm based on aggregate signature and node reputation

The alliance chain system is a distributed ledger system based on blockchain technology,which can realize data sharing and collaboration among multiple parties while ensuring data security and reliability.The Practical Byzantine Fault Tolerance(PBFT)consensus algorithm is the most popular consensus protocol in the alliance chain,but the algorithm has problems such as high complexity and too simple election of the master node,which will make PBFT unable to be applied in scenarios with too many nodes.At the same time,there are certain security issues.In order to solve these problems,this paper proposes an improved Byzantine consensus algorithm,Polymerization Signature and Reputation Value PBFT(P-V PBFT).Firstly,the consistency protocol process is improved based on the aggregate signature technology.The simulation results show that the P-V PBFT algorithm can effectively reduce the overhead of network transmission,and the time complexity of the algorithm decreases exponentially,which improves the efficiency of the consensus process.Secondly,the node reputation election mechanism is introduced to elect the primary node,and the security analysis is carried out to verify the fairness and security of the primary node election of the P-V PBFT algorithm.Therefore,as a feasible improvement of the blockchain consensus protocol,the P-V PBFT algorithm can provide more efficient and secure guarantee for the blockchain system in practical application.

A scalable blockchain-based scheme for traffic-related data sharing in VANETs

Recent advances in wireless technology and embedded systems enable vehicles to share relevant traffic-related data to improve the transportation Quality-of-Service(QoS).However,due to the ubiquitousness of cyber-attacks,it is challenging to ensure the integrity of the data collected from cars.This paper proposes a novel architecture for road traffic events management in Vehicular Ad hoc NETworks(VANETs)relying on a permissioned blockchain.It also introduces the concept of micro-transactions to minimize communication and storage overhead.Through simulations,a rigorous performance evaluation of the proposed approach was conducted,and the micro-transactions effectiveness was assessed.In addition,a comparison with close works in the literature was performed.The proposed scheme ensures road traffic records integrity and traceability,and simulation results on the considered scenarios showed good performance.