Ethereum's Privacy Push Falters on Proof Costs

A recent proposal for Ethereum's Frames transaction design has hit a roadblock due to a numbers problem. The EIP-8141 draft, submitted by AnkushinDaniil, would allow some nodes to accept heavier transactions locally while maintaining the existing validation maximum as a common floor.

However, a benchmark study found that proof verification for certain privacy designs, such as Tornado Cash and RAILGUN, exceeds the proposed 100,000-gas allowance. The optimized Groth16 proof verifier requires 190,628 gas, with a significant portion of that being attributed to cryptographic pairing checks.

The current draft caps signature checks and execution in the initial validation phase at 100,000 gas, which is intended to contain node workload and denial-of-service exposure. A larger allowance would address one obstacle for users, who currently face constraints on privacy designs sharing an address due to pending public-mempool transactions.