Offchain Labs Counters Vitalik Buterin’s RISC-V Push With Case for WASM on Ethereum L1

Offchain Labs argues Ethereum should separate delivery and proving instruction sets to maintain long-term flexibility.

The team notes rapid shifts in ZK-VM designs create uncertainty around locking Ethereum into RISC-V.

WASM offers structural stability, hardware compatibility, and strong validation features for on-chain smart contract execution.

Offchain Labs researchers advanced a detailed challenge to Vitalik Buterin’s proposal to shift Ethereum’s execution layer toward the RISC-V instruction set. Their position introduced a different structure for evaluating how Ethereum handles smart contract code. The researchers presented their findings in a November discussion on Ethereum Research, where they examined how WebAssembly can operate as a long-term delivery format for Ethereum’s Layer 1

Researchers Emphasize Distinct Roles for Delivery and Proving Systems

The team explained how smart contract systems rely on two different layers. They described a delivery instruction set that determines how contracts appear on-chain. They also detailed a proving instruction set used by ZK virtual machines to verify execution. They stated that these roles do not need to share the same design

Their post described this separation as a method that preserves flexibility for future proving systems. They referenced ongoing work that compiles WASM contracts into RISC-V before proving them. They added that this approach already runs inside Arbitrum tests that process live block data.

The researchers examined the fast changes in ZK-VM development. They noted that RISC-V implementations recently shifted from 32-bit to 64-bit designs. They stated that this change creates uncertainty around long-term optimization for proving systems. They focused on the risk of embedding a single hardware-oriented ISA into Ethereum’s base layer while other ZK-VM projects develop alternative proving structures. They referenced WASM-oriented proving efforts like Ligero’s Ligetron as examples of new directions in that landscape.

Proving Costs Continue Falling Across the Ecosystem

The post described the decline in ZK proving costs. The researchers stated that current costs sit near $0.025 for each Ethereum block. They added that costs continue to fall as proving systems evolve. They explained that these numbers reduce the need to design the delivery format around proving efficiency alone

They noted that builders can still collect gas fees and MEV that outweigh proving expenses under normal block conditions. The researchers pointed to WASM’s structured format. They explained that this structure makes code updates easier without breaking existing contracts. They added that WASM runs efficiently on common hardware used by most Ethereum nodes

They also noted that WASM includes built-in validation that enforces type safety within execution environments. They referenced its wide tooling base, which comes from extensive use across many applications. They described WASM as a stable layer that connects contract languages with diverse execution and proving systems.