Games of Miners

Conventional wisdom believes cryptocurrency miners should always work on particular token at their full power. In this paper, however, we show that miners' equilibrium strategy deviates from it, which affects the system security and energy-efficiency. Specifically, we model mining as a game where each miner has limited mining power and compete for multiple tokens. We analyze both pure Nash-equilibrium and Stackelberg-equilibrium of this game, deriving their closed-forms. It is suggested that miners might not exert full power, which, compared with fully-powered mining, provides less mining power for a token and thus makes it more vulnerable to attacks, while it helps to reduce energy consumption. Simulation results show that with more disparate capacity, this effect is more significant. Our results also show that miners should disperse power among all compatible tokens instead of only one, which matches realistic statistics well.