Ethereum (ETH) has been presented with a way to prepare quantum-resistant (post-quantum) security at the account level without a network-wide upgrade.

On June 14, blockchain outlet U.Today reported that Nico (니코), head of the Ethereum Foundation privacy project Kohaku, said a structure to prepare for the quantum-computing era could be implemented at a cost of about $0.07 per account.

The core of the proposal is to enable verification of quantum-resistant signatures on Ethereum’s current execution layer without a hard fork or the addition of separate precompiles.

In a social media post, Nico said, "Ethereum can start preparing accounts for the post-quantum era now without waiting for a hard fork." He added, "The current baseline cost is about $0.07 per account." He added that additional security audits are also planned.

Major blockchains such as Ethereum and Bitcoin currently use a digital signature system based on the Elliptic Curve Digital Signature Algorithm (ECDSA). The industry has long raised concerns that ECDSA could be neutralised if sufficiently capable quantum computers emerge.

Recent estimates of required quantum-computing resources by researchers suggested the risk could materialise sooner than expected. That has made it a key task to find ways to efficiently verify post-quantum signatures on blockchains.

To address this, researchers proposed using SPHINCS-family technology, a hash-based digital signature system. The goal is to efficiently perform stateless post-quantum signature verification in an Ethereum Virtual Machine (EVM) environment.

Specifically, they are reviewing an EVM-optimised variant model based on SPHINCS+ and recent research on compressed hash-based signatures. The focus is on lowering verification costs in a purely on-chain environment without protocol changes.

Researchers said that if a SPHINCS variant is implemented in Solidity in line with restricted signature parameters presented in a draft by the U.S. National Institute of Standards and Technology (NIST), it would be possible to verify post-quantum signatures at a practical cost level.

The proposed verification cost is about 150,000 gas. The verifier also includes a formal verification process using Lean4 and Verity. Nico said, "I conducted an initial review with Pavel and included a Verity-based formal proof."

Researchers plan to review more aggressive non-standard structures in the future. Discussions include replacing standard hash components with an EVM-friendly Keccak-based structure and reducing the signature budget to fit blockchain wallet environments. This process will also involve balancing verification gas costs, signature generation costs, signature size and the number of signatures usable per key.

In the industry, the proposal is being assessed as an example showing the possibility of responding pre-emptively at the individual account level, rather than approaching Ethereum’s shift to quantum resistance solely as a network-wide upgrade task.

If additional audits and follow-up implementations proceed successfully, discussions on introducing post-quantum security on Ethereum’s execution layer are expected to become more concrete.