Ethereum co-founder Vitalik Buterin says it is "plausible" that mathematics driven by artificial intelligence could break encryption within the next two years — a warning aimed squarely at lattice-based cryptography, one of the leading candidates for quantum-proofing blockchains.

His remarks extend the industry's quantum-readiness debate into nearer-term territory, suggesting that schemes designed to shield networks from a long-term quantum threat could, in the meantime, expose them to an AI-driven risk. For an industry built on public-key cryptography, the reframing is practical rather than academic: it bears directly on where funds can be held without their keys becoming exposed to attack.

The comments came one day after Ethereum Foundation researcher Justin Drake called on the industry to plan for "bunker mode" by moving funds to addresses whose public keys have never been exposed. Drake argued that it is now reasonable to believe advances in AI-accelerated math could break encryption before quantum computers become powerful enough to do so — the milestone commonly referred to as Q-Day.

"There is a good chance that the concrete security of lattices will take serious hits from the next two years of AI math," Buterin said on X. "If AI will bring us 50 years of math in two years, then that 50 years of math may very plausibly include a [...] level of improvement to our ability to break lattices."

In a post on X on October 7, 2026, Buterin cautioned against panic while urging the industry to take the new threat seriously:

I don't recommend anyone scramble to move their funds to new wallets today. But we should take the risks to cryptography from AI-accelerated math seriously, and minimize our exposure to not just quantum-vulnerable cryptography, but also potentially AI-vulnerable cryptography.

— vitalik.eth (@VitalikButerin) October 7, 2026

Lattice-based cryptography has been considered by several crypto projects — Cardano among them — in attempts to quantum-proof their networks. Under the reframed risk picture, users relocating funds to escape a long-term quantum threat could inadvertently park those funds at addresses vulnerable to near-term AI-assisted attacks.

"Potential breaks in cryptography by quantum computers were generally thought to be contained to elliptic curve cryptography and RSA," Isabel Foxen Duke, head of Mara Foundation and co-author of BIP-360, a Bitcoin Improvement Proposal, told Decrypt. "Breaks in cryptography by classical methods (e.g. those potentially created by AI) could affect types of cryptography that are broadly considered quantum secure (e.g. lattice-based cryptography). If we include concerns about classical breaks in the mix, we have to be even more conservative."

In light of that, Buterin argued that lattice-based schemes should increase significantly in size to improve their safety. He now views hash-based cryptography as a better route to quantum-proofing, while adding that, theoretically, AI-driven math could break hashes as well. Hash-based schemes are widely regarded as the more conservative option, resting on mathematical assumptions that have faced decades of scrutiny.

Not everyone treats the two-year timeframe as fixed. "I wouldn't treat Vitalik's two-year scenario as a deadline. The post doesn't demonstrate that these systems have been broken," Ananda Banerjee, founder of analytics firm Charlie Quant Lab, told Decrypt. "I would prepare carefully rather than rush to move funds."

For now, Buterin is not proposing drastic measures to prepare for what he calls a "plausible" doomsday scenario. He suggests keeping funds in addresses that have never made a transaction, since their public keys will not have been exposed — a condition that significantly decreases the chances of an attack. The open question across the two-year window he outlined: whether AI-driven math actually produces the gains against lattices that he described, and how projects weighing lattice-based designs respond if it does.

The warning marks a notable shift in tone. Just a month earlier, Buterin said AI would not doom crypto security, arguing that security defenses would keep pace. His latest comments suggest the industry may have been running, at least slightly, in the wrong direction.