Vitalik: Ethereum Consensus Chain Can Be Simplified to Support Millions of Validators Vitalik Buterin published a new article, *The Extremely Lean Chain*, proposing that under the context of the Lean upgrade (single-slot finality, quantum-resistant signature aggregation, etc.), Ethereum's consensus chain state requirements can be significantly reduced by shifting state management responsibilities to validators and introducing ZK proofs. Currently, the Beacon Chain stores multiple pieces of data for each validator, such as public keys, balances, and exit information, making state changes for each epoch costly. Vitalik's proposed solution removes the need to store validator public keys on-chain, eliminates the 'end-of-epoch processing' burden, and allows consensus to scale to millions of validators when needed. An advanced version could even include a mechanism for validator re-anonymization.