On the Strategy and Behavior of Bitcoin Mining with N-attackers

Selfish mining is a well-known mining attack strategy discovered by Eyal and Sirer in 2014. After that, the attackers’ strategy space has been extended by many works. These works only analyze the strategy and behavior of one single attacker. The extension of the strategy space is based on the assumption that there is only one attacker in the blockchain network. However, a proof of work blockchain is likely to have several attackers. The attackers can be independent of other attackers instead of sharing information and attacking the blockchain as a whole. During this problem, we are the teamwho for the first time analyze theminers’ behavior in a proof of work blockchain with several attackers by establishing a newmodel. Based on our model, we extend the attackers’ strategy space by proposing a new strategy set publish-n. Meanwhile, we revisit other attacking strategies such as selfish mining and stubborn mining in our model to explore whether these strategies work or not when there are several attackers.We compare the performance of different strategies through relative stale block rate of the attackers. In a proof of work blockchain model with two attackers, strategy publish-n can beat selfish mining by up to 26.3%.