Research On Security Attributes Of Blockchain PoW Protocol Under Improved Long Delay Attack

The core of Bitcoin is the blockchain technology,and the research on its security is of great practical significance and value to the development of the blockchain as a whole.Among the many increasingly acute problems facing the blockchain security,the communication delay between nodes in the blockchain network is a great challenge to the consistency of the distributed ledger maintained by individual miners in the blockchain network.Therefore,maintaining the consistency of the distributed ledger among nodes in a delayed environment and whether the current consensus mechanism can maintain good security in a complex delayed environment have attracted a lot of attention.There has been a lot of work in existing research to demonstrate that when the number of miners and the probability of successful mining are certain,the adversary can delay the block information for at most a certain number of rounds,and the PoW consensus mechanism can When the number of delayed rounds is small,the PoW consensus mechanism is able to meet good security,while when the number of delayed rounds is large,the model is still idealistic,which makes the analysis results have some limitations.For the blockchain PoW consensus mechanism in the face of a large number of delay rounds,this paper explores the security of the PoW consensus mechanism in a long latency environment by influencing the security properties of the blockchain in a complex delay environment,with the following main work:1.In order to improve the related recording model error problem,the main chain recording model of the existing blockchain PoW consensus mechanism is improved and an improved main chain recording model is proposed.The improved model improves the record error problem in the original model on the basis of ensuring the simplicity and clarity of the original model record,and introduces the specific record method,record process and model-related properties of the improved blockchain mainchain record model.At the same time,a correlation study between the improved record main chain model and three blockchain security attributes,namely common prefix,chain quality and chain growth rate,was made to demonstrate that the improved record model can effectively simulate the evolution state of the master chain under the blockchain PoW protocol within the error limit.2.In order to more accurately explore the security of the blockchain PoW consensus mechanism in a long delay environment,the impact of the relevant security properties of the improved before and after main chain record model in a long delay environment is compared.In addition,the original long delay attack model is optimized on the basis of the improved main chain record model,so that in the improved attack model,the adversary controls part of the miner computing power based on the control of miner communication,and the corrupt miner computing power controlled by the adversary has strong flexibility and can be mined dynamically on different chains to which the adversary belongs under specific conditions,and the influence of relevant parameters on the success rate of the adversary attack is analyzed.The success rates of adversary attacks are compared with those of different attack models before and after the improvement.