The mechanism is simple enough for an ordinary wallet. Once an account sends a transaction, its public key is visible onchain forever. A powerful enough quantum computer could, in theory, work backwards from that to the private key and sign transactions as the owner.
The upcoming Hegotá upgrade, scheduled for 2027, itself will not make Ethereum quantum-resistant. What it does is keep the later work on schedule, which the Foundation put bluntly: “Hegotá is not the PQ fork. It is the fork that decides whether the PQ forks happen on time.”
Sitting behind Hegotá are the proposals doing the cryptographic work. Two of them would let accounts drop secp256k1, the signature system Ethereum has used since launch, as their master key. A third begins retiring validator withdrawal credentials still tied to it, extending the deposit contract redesign CoinDesk covered last month.
Read More: Ethereum commits to letting users pay gas fees without having to hold ETH
The schedule leaves little room. Five hard forks are planned after Hegotá, which works out at one approximately every 7.2 months, and the Foundation says they will have to overlap rather than ship in sequence.
These milestones include leanSPHINCS, a hash-based signature scheme, post-quantum attestations for validators, and a public key registry. There is also a fallback called minimum viable post-quantum protection, meant to keep the network running through a quantum breakthrough with reduced guarantees if the full rebuild is not finished.
