Ethereum Foundation privacy project Kohaku lead Nico said Ethereum accounts can start preparing for post-quantum risks without waiting for a hard fork.
Summary
- Nico says Ethereum accounts can start quantum protection now without waiting for protocol changes.
- SPHINCS- aims to verify post-quantum signatures on Ethereum at practical on-chain costs for wallets.
- Ethereum’s roadmap already names privacy, security, and post-quantum work as core technical priorities.
In a June 2026 post on X, Nico wrote, “Ethereum can already start preparing accounts for a post quantum world, without waiting for a hard fork.”
The researcher said the current cost would be about $0.07 per account. The claim points to account-level protection, not a full chain upgrade. That means users or wallet teams could add protection through smart contract logic while Ethereum developers keep working on longer-term protocol changes.
SPHINCS- targets low-cost EVM verification
The technical post on Ethereum Research describes SPHINCS-, an EVM-optimized family of stateless post-quantum signatures. The design comes from SPHINCS+ and newer work on compact hash-based signatures. Its goal is to cut on-chain verification cost without using a precompile or changing Ethereum rules.
Nico’s post says a Solidity verifier can already check a post-quantum-style signature on Ethereum at practical cost. One optimized variant, called C13, verifies at about 127,000 gas and uses a 3,704-byte signature. The research also includes a Lean 4 formal proof through Verity.
The problem it tries to solve is simple. Today, Ethereum and Bitcoin accounts rely on ECDSA signatures. Researchers warn that strong future quantum computers could break that type of cryptography. SPHINCS- uses hash-based signatures, which aim to resist those attacks.
Privacy and security remain priorities
Recent crypto.news coverage shows the proposal fits a broader Ethereum roadmap. Vitalik Buterin has discussed account abstraction, which lets wallets define how transactions are approved and paid. Moreover, account abstraction forms part of Ethereum’s short-term privacy plan with FOCIL and keyed nonces.
As previously reported, Buterin said the Ethereum Foundation would focus more tightly on long-term survival, security, privacy, openness, and censorship resistance. That same coverage said Ethereum roadmap work includes post-quantum security and formal verification as future goals.
Moreover, externally owned account signatures using ECDSA are one area exposed to future quantum attacks. For wallets, the report said native account abstraction could let accounts adopt post-quantum signature schemes once efficient options exist.
Audits and limits still matter
Nico said the design has gone through an initial review with Fable, with more audits planned. That review does not make the system final. The Ethereum Research post notes limits, including non-standard settings, bounded signature counts, and a difference between Keccak-based designs and NIST-aligned versions.
For users, the key point is that Ethereum may not need to wait for a full protocol change before wallets begin testing quantum-resistant account protection. For developers, the next steps include more review, safer wallet flows, clearer cost models, and better hardware support.
The account path matters because many funds sit in old-style addresses. A wallet-based route could let high-value accounts test protection before Ethereum adopts broader changes through later technical upgrades, proposal rounds, and wider public review.
The proposal does not mean Ethereum faces an immediate quantum attack. It also does not replace future network-level work. It does show that account-level defenses can move from research into testing today, at a cost that Nico says is low enough for wide trials.
