Research Of Clustered ZC Service Based On Cloud Computing And Blockchain Technology

Communication Based on Trian Control System(CBTC)system has problems such as low hardware utilization and difficult maintenance,and it is difficult to meet the future high-quality,low-latency train control needs.In addition,the safety computing platform in the signal system is limited by hardware and has poor scalability,and its centralized architecture also has the risk of a single point of failure.Cloud computing has been gradually promoted in the field of urban rail transit due to its advantages of efficient resource utilization,flexibility and scalability,and low energy consumption.However,at this stage,the plan for migrating CBTC systems to cloud computing platforms is not yet mature.Therefore,it is necessary to analyze the characteristics of the CBTC system and cloud computing platform,fully study the migration scheme of CBTC safety-related subsystems to the cloud,and promote the application of cloud computing in the field of urban rail transit.In this paper,by analyzing the characteristics of the security redundancy structure and cloud computing in the CBTC system,taking the ZC system as an example,the overall scheme of the cloud computing-based clustered ZC service system is proposed on the basis of integrating blockchain decentralization technology.According to the underlying principles of blockchain to achieve decentralization,research and design exclusive consensus algorithms and smart contracts.By establishing a reputation evaluation strategy for nodes in the cluster,the influence of malicious nodes in the cluster on the consensus process is avoided.The paper has done the following work:(1)According to the characteristics of the CBTC system,analyze the signal system,especially the possible single point of failure in the security redundancy architecture of the ZC subsystem,and propose a strategy to decentralize the ZC subsystem.According to the cloud computing architecture and the ZC subsystem The functional characteristics of the system,put forward the overall scheme of cloud computing-oriented cluster ZC service;(2)Design a dedicated blockchain system for cloud computing-oriented clustered ZC service systems.By analyzing the service requirements of the ZC system,designing a system-specific block structure,drawing on the advantages of mature consensus algorithms,and designing an exclusive consensus algorithm-Po TH on the basis of meeting the ZC service requirements.In addition,in order to prevent the Byzantine failure problem caused by malicious nodes doing evil in the consensus process,a node trust evaluation mechanism and exclusive smart contract are designed;(3)Analyze the security and communication of the clustered ZC structure,analyze the impact of the cloud computing environment on the security and reliability of the clustered architecture,establish a security and reliability index model through the reliability block diagram,and calculate it through the Monte Carlo method For the specific values of security and reliability,in order to analyze the delay and bandwidth of the cluster service,the response delay model of the cluster service is established through the random network calculus method,and the bandwidth of the cluster ZC is predicted based on the ARIMA model;(4)The overall performance verification of the cloud computing-oriented clustered ZC service system.Write a blockchain program,give the minimum system deployment method in the container mode,establish an attack tree for information security,analyze the ability of the consensus algorithm to fight against information risks,and verify the impact of the block size and the number of cluster nodes on the consensus algorithm throughput and consensus delay,cycle stability,etc.The experimental results show that the security of the clustered ZC proposed in this paper meets the SIL4 standard and its reliability is higher than that of the traditional ZC system.In terms of usability,the average delay of the Po TH consensus mechanism proposed in this paper is 4.33 ms,and the standard deviation of multiple tests is 0.173 ms.The cycle is stable,and under the condition of the maximum delay of 100 ms,it can meet the operation of 40 trains.