  Temporary fork is a fundamental phenomenon in many blockchains with proof of
work, and the analysis of temporary fork has recently drawn great attention.
Different from existing efforts that focus on the blockchain system factors
such as block size, network propagation delay or block generation speed, in
this paper we explore a new key dimension of computing power from the miners'
perspective. Specifically, we first propose a detailed mathematical model to
characterize the impact of computing power competition of the mining pools on
the temporary fork. We also derive closed-form formula of the probability of
temporary fork and the expected mining reward of a mining pool. To reveal the
long-term trends on the computing power distributions over the competing mining
pools, we then develop an evolutionary game framework based on the temporary
fork modeling and accordingly characterize the set of stable evolution
equilibriums. Both extensive numerical simulations and realistic blockchain
data based evaluation provide evidence to support our theoretical models and
discoveries.
