A Biform Game Approach to Preventing Block Withholding Attack of Blockchain Based on Semi-CIS Value

Abstract

In proof-of-work (PoW)-based blockchain network, the blockchain miners publish blocks by contributing computing power to solve crypto-puzzles. Due to the weak computing power of single miner, miners tend to join a mining pool and share the profits from the mining pool according to the contribution proportions of the miners. However, some miners may initiate block withholding attack which may result in wasting computing power, even threatening the efficiency of the blockchain network. To address this problem, in this paper, we use the biform game model to optimize the miners’ strategy choices. We firstly formulate the mining process as a non-cooperative–cooperative biform game model. We use the model to exhibit miners’ strategy choices (non-cooperation stage) and the cooperation mining process (cooperation stage). Then we set the conditions to maintain the voluntary honest behavior of miners. After that, we employ the semi-CIS (semi-the center of imputation set value) value to compute the solutions of the cooperative games in the cooperation stage, and optimize miners’ strategy choices to prevent the block withholding attack. Hence we can ensure the blockchain network is secure. Finally, the validity and applicability of the proposed model and method are verified by a numerical example.