Vitalik Buterin Proposes Radical Ethereum Overhaul

Ethereum co-founder Vitalik Buterin has unveiled a proposal that could fundamentally reshape the execution layer of the world's second-largest blockchain: replacing the Ethereum Virtual Machine (EVM) with RISC-V, an open-standard instruction set architecture commonly used in modern CPUs.

In a blog post on Sunday, Buterin argued that this radical shift could lead to a 50-100x increase in the efficiency of zero-knowledge (ZK) proofs, unlocking unprecedented scalability for the Ethereum network.

Buterin's proposal directly addresses what he identifies as a key long-term bottleneck for Ethereum's scalability: the proving capabilities of ZK-EVMs. ZK-EVMs are crucial for scaling solutions like zk-rollups, which bundle multiple transactions off-chain and then use zero-knowledge proofs to cryptographically verify their validity on the main Ethereum chain.

As Buterin explained, "In the long term, the primary limiting factors on Ethereum L1 scaling become...(1) Stability of data availability sampling and history storage protocols, (2) Desire to keep block production a competitive market, (3) ZK-EVM proving capabilities. I will argue that replacing the ZK-EVM with RISC-V solves a key bottleneck in (2) and (3)."

The core of the issue lies in the inherent inefficiency of the EVM for ZK proving. RISC-V zkVMs can operate in two modes: natively executing code compiled directly to RISC-V, or interpreting EVM bytecode. Research from Succinct , a ZK-focused company, indicates that the EVM interpreter can introduce an 800x overhead in ZK proving times. This significant overhead is a major impediment to achieving faster and cheaper layer-2 scaling solutions.

By adopting RISC-V as the native execution environment for smart contracts on Ethereum, Buterin proposes to bypass this inefficient interpretation layer. This could make ZK proofs of Ethereum blocks more efficient, potentially reducing proof generation times from minutes to mere seconds. This improvement would translate to significantly faster layer-2 networks, cheaper rollup transactions, and ultimately, much greater scalability for the entire Ethereum ecosystem.

Addressing concerns about developer experience and compatibility, Buterin outlined several potential implementation paths. The least disruptive approach would involve supporting both the EVM and RISC-V as parallel virtual machines, allowing new smart contracts to be written in either. Crucially, both types of contracts would have full interoperability, capable of calling each other seamlessly.

More radical approaches include converting existing EVM contracts to call an EVM interpreter written in RISC-V, or even enshrining the concept of a "virtual machine interpreter" within the Ethereum protocol itself, with the EVM being the first, but potentially not the only, such interpreter written in RISC-V. Buterin argues that these more radical options could "greatly simplify the execution layer spec," potentially leading to a much leaner and more efficient base layer for Ethereum.

While the potential benefits of this transition are substantial, the proposal acknowledges significant challenges. The development of new tooling, audit frameworks, infrastructure, and compilers for RISC-V on Ethereum would be a massive undertaking, likely spanning several years. Furthermore, gaining consensus and driving adoption across the vast Ethereum ecosystem will be a considerable hurdle.