Why Vitalik believes quantum computing could break Ethereum’s cryptography sooner than expected

Ethereum co-founder Vitalik Buterin has raised concerns that quantum computers capable of breaking current cryptography might arrive sooner than generally expected, citing forecasting platforms that suggest a non-trivial 20% chance of this occurring before 2030, with a median forecast around 2040. The primary vulnerability lies in the Elliptic Curve Digital Signature Algorithm (ECDSA), which secures Ethereum and Bitcoin. Once a user transacts, their public key is revealed on-chain, allowing a future quantum computer using Shor's algorithm to potentially derive the private key and drain the account.

Buterin advocates for proactive preparation, framing quantum readiness as a necessary research roadmap item rather than a distant concern. His proposed "quantum emergency" hard-fork plan involves rolling back the chain, freezing legacy Externally Owned Accounts (EOAs), and routing funds into quantum-resistant smart contract wallets via zero-knowledge proofs. This plan is a last resort, emphasizing that the necessary infrastructure, like account abstraction and robust ZK-proof systems, should be built now.

While hardware experts suggest breaking 256-bit ECC requires millions of qubits, far beyond current capabilities, Buterin's argument centers on the long migration lead times required for a global network. Mitigation strategies include adopting NIST-approved post-quantum signatures (like ML-DSA/SLH-DSA), ensuring crypto-agility across the stack (including BLS signatures and proving systems), and building mechanisms like quantum canaries to automatically trigger migration rules.

(Source：Cointelegraph)