Simple Hard Fork: Protecting Ethereum from Quantum Attacks

Ethereum co-founder Vitalik Buterin believes that Ethereum is already in a good position to protect itself against a massive quantum computing attack. In a recent post on Ethereum Research, Buterin explored what would happen if a “quantum emergency” occurred as early as tomorrow. He argued that a recovery fork could be implemented to handle such a situation relatively easily.

In this hypothetical scenario, Buterin suggests that if quantum computers were made available to bad actors who used them to steal users’ funds, the blockchain would need to undergo a hard fork. Users would then need to download new wallet software, but only a few would actually lose their funds. The hard fork would involve rolling back the Ethereum network to the point where it is clear that large-scale theft had taken place.

One of the key steps in this process would be the introduction of a new transaction type. This transaction type, outlined in the Ethereum Improvement Proposal (EIP) 7560, would allow transactions from smart contract wallets. In a “post-quantum world,” the user’s private key would be revealed when making a transaction from their Ethereum wallet. The new transaction type, utilizing Winternitz signatures and zero-knowledge proof technologies known as “STARKs,” would enable existing wallets to be switched to new validation code.

By leveraging ERC-4337 account abstraction, the validation code used in smart contract wallets would prevent private keys from being displayed while signing transactions. This would make these accounts immune to a quantum attack. Buterin noted that users who have not approved a transaction from their Ethereum wallet are already safe, as only their wallet address is publicly available.

Buterin also mentioned that the infrastructure needed for implementing such a hard fork could begin to be built right away, making Ethereum more resilient to quantum computing attacks. Quantum computing has long been a concern in the crypto industry, as it has the potential to break blockchain encryption and facilitate the theft of user funds. Many computer scientists and developers believe that quantum computing is still years away from being sufficiently developed for such attacks, estimating that it won’t be ready until at least 2029.