



01524nas a2200145   4500008004100000245004700041210004400088260001500132520110100147100003701248700001801285700001901303700001901322856003701341       2019                        eng d00aCompeting (Semi)-Selfish Miners in Bitcoin0 aCompeting SemiSelfish Miners in Bitcoin  c06/11/20193 a<p>The Bitcoin protocol prescribes certain behavior by the miners who are responsible for maintaining and extending the underlying blockchain; in particular, miners who successfully solve a puzzle, and hence can extend the chain by a block, are supposed to release that block immediately. Eyal and Sirer showed, however, that a selfish miner is incentivized to deviate from the protocol and withhold its blocks under certain conditions. The analysis by Eyal and Sirer, as well as in followup work, considers a \emph{single} deviating miner (who may control a large fraction of the hashing power in the network) interacting with a remaining pool of honest miners. Here, we extend this analysis to the case where there are \emph{multiple} (non-colluding) selfish miners. We find that with multiple strategic miners, specific deviations from honest mining by multiple strategic agents can outperform honest mining, even if individually miners would not be incentivised to be dishonest. This previous point effectively renders the Bitcoin protocol to be less secure than previously thought.&nbsp;</p>1 aMarmolejo-Cossío, Francisco, J.1 aBrigham, Eric1 aSela, Benjamin1 aKatz, Jonathan  uhttps://arxiv.org/abs/1906.04502