关键词: 区块链, 51%双花攻击, 进化博弈, 交易费用, 交易价格

Abstract: As a security risk in the field of payment, the double spend attack has brought a serious impact on the normal operation of the blockchain system. Aiming at 51% double spend attacks with strong destructive force in double spend attacks, an evolutionary game model of 51% double spend attacks in blockchain is built to reveal the dynamic evolution trend of node strategies, and the probability of 51% double spend attacks is predicted by deducing evolutionary stability strategies. At the same time, transaction price and transaction fee are taken as two important variables in evolutionary game model to explore the influence of different values of this variable on game results. Simulation experiments verify the effectiveness of the above model, and finally the risk prevention and control strategy and suggestions are put forward from the two aspects of transaction fee and transaction price.

Key words: blockchain, 51% double spend attack, evolutionary game, transaction fee, transaction price