Vitalik Buterin, co-founder of Ethereum, published a short article titled "How to Rescue User Funds from a Sudden Quantum Attack with a Hard Fork" at the Ethereum Research Forum (ethresear.ch).
In the article, Vitalik mentions that if the quantum attack comes earlier than expected, and the account abstraction has not yet fully landed, Ethereum can also solve the problem through a "recovery fork", at which time the fork-related changes are as follows:
First, roll back all blocks after a large-scale attack;
second, disabling the traditional trading model based on EOA addresses;
third, (if it hasn't already been implemented by then) to add a new transaction type that allows transactions through smart contract wallets (such as some in RIP-7560);
Fourth, add a new transaction type or opcode, through which the user can provide a STARK proof, and if the proof passes, the code of the user's address will switch to the new verified code, and then the user can use the new code address as a smart contract wallet.
Fifth, in order to save gas, due to the large amount of data in STARK proofs, we will support batch STARK proofs to conduct multiple STARK proofs of the above types at the same time.