Block withholding attack is an action where a miner who has found a legal block chooses not to submit it but rather directly abandons it. This attack makes the mining pool lose all bitcoin rewards contained within the block. In this paper, we construct a generalized model where two participants can choose to either cooperate with each other or employ a block withholding attack in the mining pool. To make the model more realistic, we consider both the cost of partial proof of work and the cost of cooperation. We also calculate the reward-per-time instead of profit-per-time to better measure the payoffs of each party. Further, we discuss the case where the payoff function and cost function are directly related to the computational power. The pure strategy and mixed strategy are analyzed respectively and the segmentations of the equilibrium are shown. We demonstrate that increasing the information asymmetry by utilizing information conceal mechanisms could lower the occurrence of the BWH attack. 1. Introduction The concept of Bitcoin was originally proposed by Nakamoto [1], and it is basically known as an open source software and a P2P network constructed on the software. Unlike most existing currencies, Bitcoin does not rely on a specific currency institution for its creation and distribution. Instead, it is generated by a large number of calculations based on a specific algorithm. The Bitcoin economy uses a distributed database of nodes in the entire P2P network to confirm and record all transaction behaviors, and it employs cryptographic design to ensure the security of all aspects of currency circulation. The advantages of this new economy include decentralization, worldwide circulation, exclusive ownership, lower transaction costs, no hidden costs and crossplatform mining. Swan [2] performed a detailed introduction to blockchain, which includes the concepts, features and functionality of Bitcoin and how one can use the blockchain for automated tracking of all digi