A developer under the pseudonym Valisthea published this April 14 on the Ethereum Magicians forum a standard proposal (ERC) to register and manage cryptographic keys resistant to quantum computers directly on the network, without needing to modify the base protocol or wait for the consensus of the entire developer community.
Valisthea’s ERC operates on a different layer. Instead of modifying Ethereum from within, it proposes a smart contract that any project can adopt today independently. Each Ethereum address could register, activate, rotate or revoke its post-quantum keys without touching the existing infrastructure. The standard defines a clear life cycle for each key: it goes from registered to active, then it can be rotated or revoked, and each state is audited in a chain.
In order not to break compatibility during the transition, the proposal includes a mode double signature: Contracts that implement it can require both a classical signature with the current Ethereum system and a post-quantum signature on the same message. If one of the two schemes were compromised, the other would continue to protect the operation.
The proposal comes at a time when the quantum threat to distributed ledger networks (blockchain) went from being a theoretical debate to an operational priority. In January 2026, the Ethereum Foundation formalized a team dedicated to post-quantum security and published a roadmap structured into four milestones in March. The problem: none have a specific date and all require profound changes to the protocol, that is, a hard fork or bifurcation that requires coordination of the entire network.
What problem does it solve that the official roadmap cannot yet address?
One of the risks that justify the urgency is the so-called harvest now, decrypt later or “harvest today decrypt later”: actors with sufficient resources could already be recording signed transactions on Ethereum to decrypt them in the future, when they have capable quantum computers. Every public key exposed on-chain is, in that scenario, a potential target. The proposal does not solve this problem at the protocol levelbut it does give projects a standard tool to start operating with resilient keys before that threat arrives.
The proposal opens up several points of debate for the community: what minimum level of NIST security should be required, whether keys are stored in full on-chain—at a cost of up to 100,000 gas units per record—or just their hash identifier, and how to handle key portability between Ethereum and its second-layer networks.
The underlying question that Valisthea raises is whether Ethereum will have standard infrastructure ready when real quantum pressure hitsor if each project will end up building its own solution ad hoc.