Research On Blockchain Sharding Technology For Edge Computing

Existing edge computing systems are faced with security challenges.They cannot guarantee the security of stored data and task execution results.Blockchain is a distributed shared ledger and database,which has the characteristics of decentralization,immutability,traceability,collective maintenance,openness and transparency,etc.Therefore,it is considered as one of the effective ways to solve security problems.However,the scalability of blockchain is poor,and the edge computing system is faced with large-scale Internet of Things(IoT)applications,which have high requirements for throughput and delay performance,which become obstacles for the application of blockchain in the edge computing system.To solve above problems,the blockchain and the sharding technology are applied in the edge computing system in this paper,which improves the security of the edge computing system,reduces the delay and improves the throughput.The main research contents of this paper are as follows:1)For scenarios where all tasks in the IoT have the same security or latency requirements,this paper proposes a secure edge computing framework based on blockchain and sharding technology.In the proposed scheme,by grouping edge nodes and unloading tasks,multiple edge node groups agree on different task sets in parallel,so as to improve the security of edge computing system and the scalability of Blockchain.We analyze and simulate the security,delay and system throughput performance of the proposed scheme.The simulation results show that the proposed scheme improves the scalability of the system under a certain security level compared with the non-sharding scheme.For example,when the proportion of malicious nodes is 20%,the throughput of the proposed scheme is 5 times that of the unsharded scheme while ensuring the system security of 98%.On the other hand,the proposed scheme improves the security while keeping the service delay within the threshold.For example,when the proportion of malicious nodes is 20%,the security of the proposed scheme can be improved by 20%compared with the existing edge computing system when the service delay is not more than 0.2s.2)In a multiple types of tasks scenario,there are tasks with different requirements for security or delay.For example,the real-time broadcast in the Internet of Vehicles is more sensitive to delay,while the financial field has higher requirements for security.This paper proposes a multi-level sharding scheme based on Generic Algorithm(GA).In the proposed scheme,edge node groups are divided into different levels,and the parameters of different levels are different,so as to meet the QoS requirements of various tasks.Moreover,the proposed scheme uses GA to allocate resources to optimize system performance.Simulation results verify the superiority of the proposed scheme.For example,when the proportion of malicious nodes is 20%,the throughput of the proposed scheme is about 3.5 times that of the single-level sharding scheme,which is 17%higher than that of the resource-allocation scheme based on proportion.The security of the proposed scheme is 14%higher than that of the single-level sharding scheme,and 3%higher than that of the proportional resource allocation scheme.The edge computing system based on sharding technology proposed in this paper solves the security problem of the edge computing system and the problem of poor scalability of the blockchain,and makes it more in line with actual requirements.The proposed scheme improves the security of the edge computing system while keeping the service delay within the threshold.At the same time,the proposed scheme improves the throughput of the edge computing system,and can meet the large-scale operation of the IoT.