Vitalik Proposes Deep Overhaul of Ethereum
Vitalik Buterin has identified Ethereum's state tree and EVM as its biggest technical bottlenecks. He's floating a radical shift to binary state trees and potentially replacing the EVM with RISC-V to improve efficiency, a move that would fundamentally alter the network's architecture.
The proposed overhaul addresses Ethereum's "state bloat," an issue where the ever-expanding record of accounts and contract data makes it increasingly difficult and costly for new nodes to sync and participate, potentially threatening decentralization. Researchers have noted that approximately 80% of the network's state has not been accessed in over a year, yet all nodes are required to store it. This proposal, outlined in EIP-7864, would swap Ethereum's current hexary Merkle-Patricia tree for a binary state tree. This change is expected to make Merkle branches about four times shorter, significantly cutting bandwidth and data costs for light clients and verification processes. The new binary tree design also introduces "pages" for storage, which could save DeFi applications over 10,000 gas per transaction by allowing more efficient access to adjacent storage slots. The potential move from the Ethereum Virtual Machine (EVM) to RISC-V is driven by the need for greater efficiency in a zero-knowledge (ZK) future. The EVM's 256-bit, stack-based architecture is inefficient for generating proofs, creating performance bottlenecks for ZK-EVMs. In contrast, RISC-V is a modern, open-source, and register-based architecture that aligns better with existing ZK provers and offers significant performance gains. A transition to a RISC-V virtual machine would be phased in to ensure backward compatibility. The initial stage would involve using the new VM for precompiles, followed by allowing developers to deploy contracts directly in RISC-V. Ultimately, the EVM itself would be retired and converted into a smart contract running on the new, more efficient VM. This isn't the first time a major change to Ethereum's core logic has been managed; the successful "Merge" serves as a precedent for executing such complex, in-flight upgrades to the network. However, the RISC-V proposal faces debate, with some, like researchers from Offchain Labs (the team behind Arbitrum), arguing that WebAssembly (WASM) would be a better long-term choice for Ethereum's smart contract format.
