Research On Attack Behaviors And Defense Strategies In Blockchain

Since the advent of Bit coin,blockchain technology has attracted the attention of many domestic and foreign scholars in recent years due to it s decent ralizat ion,security,and traceability.More and more f ields such as f inance,ident ity authent ication,and the Internet of Things have been invested in the research on blockchain.While the research on blockchain technology in many fields is gradually deepening,there are more and more attacks on the blockchain,which seriously threatens the development of blockchain technology.The research on blockchain security is very important,and it is very important to study the attack behavior in the blockchain and propose a defense strategy for the development of the blockchain.This thesis studied the attack behavior and defense strat egy in the blockchain.focusing on the block w ithholding attack and it s defense st rategy in the blockchain.Block w ithholding attack exist in the blockchain system represented by B itcoin.Aiming at the block w ithholding attack,after analyzing the profit rat e and speed of the exist ing block w ithholding attack model,a block w ithholding attack model w ith increased prof it speed is constructed.Analyzed the comput ing power and revenue of the constructed model.By introducing the time parameter t,the const ruct ed block withholding attack model is d ivided into three st ages,each stage of the model is constructed separately,and the attacks of the const ruct ed model are analyzed stage by stage,then the const ructed model is verif ied by experiment s,and the results show that it can indeed increase the speed of the attacker's income.Finally,the application scenarios of the const ructed model are analyzed based on the experimental results.Based on the bad influence of the block w ithholding attack,the defense st rategy of the block w ithholding attack is studied.Through the research and analysis of the working principles of various defense strat egies,the various defense strat egies are summarized and classified according to their characteristics,and the two feasible defense strategies are verified and analyzed in various aspects.Experiment s show that the defense of two st rategies is effective,based on the experimental result s,the defense effect and applicable scenarios of the defense strategy are analyzed.This thesis combined the blockchain w ith power trading and studies the impact of block w ithholding attacks on blockchain power trading.In response to the decrease in revenue and abnormal computing power caused by block withholding attacks on blockchain power transactions,a power t rading scheme that can defend against block withholding attacks is proposed.In the plan,the price game is used to compete for the right to sell electricity and to determine the elect ricity price,and to maintain the legal progress of the transact ion by adopting an additional reward distribution plan.Experiments show that this scheme can protect the revenue of user nodes and effectively defend against block withholding attacks.