Research On Behavior Analysis And Optimal Decision Of Bitcoin Mining Pools Based On Game Theory

With the popularity of Bitcoin,mining pools have become the main producer of Bitcoin and are at the focus of people’s eyes.As early as 2011,there were reports of DDoS attacks on mining pools.Until this year,there are still DDoS attacks against mining pools.DDoS attacks bring tremendous harm.For the attacked mining pools,the computing resources are wasted.For Bitcoin economy and ecological environment,the mining market is disturbed.Research shows that in these DDoS attacks,the mining pool is an important source of attack.Therefore,it is of great significance to study the role and motivation of the mining pool in DDoS attacks.This paper studies the motivation of DDoS attack,the possibility of cooperation between mining pools and the optimal decision of "bounded rationality" mining pools.The conclusions are as follows.In view of the motivation of Bitcoin mining pools to launch DDoS attacks,this paper establishes a one-round game theory model.Through the theoretical analysis and numerical analysis of Nash equilibriums,the conclusions are as follows:(1)The big mining pool is more likely to launch DDoS attacks than small mining pool;(2)The greater the computing power gap between the big mining pool and the small mining pool,the more likely big mining pool will choose DDoS attack strategy;(3)It is not a Nash equilibrium that the small mining pool chooses to launch DDoS attacks while the big mining pool does not.As for the possibility of cooperation between mining pools,the mining game in real life does not end in one round,but runs for multiple rounds.So a repeated model is established in this part for analysis.The results are as follows:(1)If the discount factor of block reward is bigger than one half,the cooperation between mining pools can continue;(2)According to the classic Axelrod experiment,the response strategy of mining pools under DDoS attack is designed,which is defined as "mining-repeat,DDoS attack-change" response strategy.Through analysis,this strategy can promote the cooperation between mining pools and achieve a peaceful mining state.Eventually for the optimal decision-making of the mining pools,considering that the mining pools as participants are "bounded rational",the equilibrium is achieved by trials and errors.Based on this,this paper establishes an evolutionary game model.By establishing the replication dynamic equation and analyzing the evolutionary stable strategy,the optimal strategy selection algorithm of the mining pool is obtained.In addition,there are simulation experiments in this part combining analysis with the actual scenes.