Timing the Head in Ethereum PoS

An ethresear.ch post describes timing-based attacks on Ethereum PoS head votes, where an adversarial proposer delays block release near the attestation deadline or withholds k consecutive proposer slots to build a private branch, causing honest validators to lose head-vote rewards and potentially triggering reorganizations. Prysm experiments show the head-vote timing game produces a 15.06% average total reward loss for honest validators, and under k-block withholding coordinated adversaries can accumulate enough private fork-choice weight to realize a reorganization. The authors propose a distance-weighted head reward that gives partial rewards for recent canonical ancestors, reducing the timing-game loss from 15.06% to 4.71% while leaving HLMD-GHOST and proposer boost unchanged.