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

"In late 2025, Ethereum co-founder Vitalik Buterin did something unusual. He put numbers on a risk that is usually discussed in sci-fi terms. Citing forecasting platform Metaculus, Buterin said there is "about a 20% chance" that quantum computers capable of breaking today's cryptography could arrive before 2030, with the median forecast closer to 2040. A few months later at Devconnect in Buenos Aires, he warned that elliptic curve cryptography, the backbone of Ethereum and Bitcoin, "could break before the next US presidential election in 2028.""

"A key risk involves ECDSA. Once a public key is visible onchain, a future quantum computer could, in theory, use it to recover the corresponding private key. Buterin's quantum emergency plan involves rolling back blocks, freezing EOAs and moving funds into quantum-resistant smart contract wallets. Mitigation means smart contract wallets, NIST-approved post-quantum signatures and crypto-agile infrastructure that can swap schemes without chaos."

"Did you know? As of 2025, Etherscan data more than 350 million unique Ethereum addresses, highlighting how widely the network has grown even though only a small share of those addresses hold meaningful balances or remain active. Your private key is a large random number. Your public key is a point on the curve derived from that private key. Your address is a hash of that public key."

A forecast assigns about a 20% probability that quantum computers capable of breaking current public-key cryptography could arrive before 2030, with a median estimate nearer 2040. Elliptic curve cryptography (ECDSA), used by Ethereum and Bitcoin, is particularly vulnerable because revealed onchain public keys could enable private-key recovery by a sufficient quantum attacker. Proposed emergency responses include rolling back blocks, freezing EOAs, and migrating funds into quantum-resistant smart contract wallets. Long-term mitigation requires adoption of NIST-approved post-quantum signature schemes, wider smart-contract wallet use, and crypto-agile infrastructure able to swap cryptographic schemes without systemic disruption.

Read at Cointelegraph