A Game Theoretic Analysis of Validator Strategies in Ethereum 2.0
Chien-Chih Chen, Wojciech Golab
TL;DR
The paper investigates Ethereum 2.0 validator incentives by modeling the one-slot interaction between block proposers and attesters as a Bayesian game. It develops a comprehensive reward, penalty, and cost framework and proves that cooperation—keeping devices online—forms a Bayesian Nash equilibrium and an ex ante dominant strategy, implying incentive compatibility for individual validators. By formalizing utilities and strategies, the authors show that the Eth2 incentive mechanism promotes validator cooperation within a slot, supporting reliability and protocol adherence. The study contributes a rigorous Bayesian game formulation for Eth2, derives equilibrium results, discusses practical implications for validator participation, and highlights open questions including MEV, delegated staking, and external factors for future work.
Abstract
Ethereum 2.0 is the second-largest cryptocurrency by market capitalization and a widely used smart contract platform. Therefore, examining the reliability of Ethereum 2.0's incentive mechanism is crucial, particularly its effectiveness in encouraging validators to adhere to the Ethereum 2.0's protocol. This paper studies the incentive mechanism of Ethereum 2.0 and evaluates its robustness by analyzing the interaction between block proposers and attesters in a single slot. To this end, we use Bayesian games to model the strategies of block proposers and attesters and calculate their expected utilities. Our results demonstrate that the Ethereum 2.0 incentive mechanism is incentive-compatible and promotes cooperation among validators. We prove that a Bayesian Nash equilibrium and an ex ante dominant strategy exist between the block proposer and attesters in a single slot. Our research provides a solid foundation for further analysis of Ethereum 2.0's incentive mechanism and insights for individuals considering participation as a validator in Ethereum 2.0.