Three Attacks on Proof-of-Stake Ethereum

Recently, two attacks were presented against Proof-of-Stake (PoS) Ethereum: one where short-range reorganizations of the underlying consensus chain are used to increase individual validators’ profits and delay decisions, adversarial network is leveraged stall decisions indefinitely. We provide refined variants these attacks, considerably relaxing requirements on stake timing, thus rendering more severe. Combining techniques from both we obtain a third attack which allows an adversary with vanishingly small fraction no control over message propagation (assuming instead probabilistic propagation) cause even long-range reorganizations. Honest-but-rational or ideologically motivated validators could use this their protocol, threatening incentive alignment security PoS Ethereum. The can also lead destabilization congestion in vote processing.