Ethereum proposes $0.07 post-quantum signature scheme

Ethereum developers are exploring a new method to protect user accounts from future quantum computing threats at a minimal cost and without requiring a major network upgrade. According to a proposal from Ethereum Foundation researcher Nicolas Consigny, users could begin adding post-quantum protections for an estimated cost of as little as $0.07 per action.

Consigny detailed the approach, dubbed SPHINCS-, in a social media post on Saturday, June 13, and a corresponding research paper. The proposal adapts SPHINCS, a post-quantum signature standard developed by the U.S. National Institute of Standards and Technology (NIST), to function more efficiently on the Ethereum Virtual Machine (EVM). The goal is to significantly reduce the on-chain verification costs associated with quantum-resistant signatures without needing a protocol hard fork or a new precompile.

The researcher described SPHINCS- as an intermediate step or "bridge" toward a future, more optimized system called leanSPHINCS, which aims to further lower costs through signature aggregation. The motivation is the long-term theoretical risk that powerful quantum computers could break the Elliptic Curve Digital Signature...