A new report from Project Eleven drops a hard number on the table: roughly 65% of Ethereum's supply and every single Solana token sits in wallets that a quantum computer could theoretically crack today. The researchers mapped out exactly which cryptographic primitives are at risk — and it's not just user accounts.
Three weak spots on Ethereum
Ethereum's quantum exposure isn't limited to the ECDSA keys that control user wallets. The report flags two more attack surfaces: the BLS signatures that secure proof-of-stake consensus and the KZG commitments used for blob data under EIP-4844. If a quantum attacker recovered validator BLS keys — which are publicly visible from the moment a validator deposits 32 ETH — they could forge attestations, destabilize the chain, and trigger mass slashing. That's a worst-case scenario the Foundation is trying to get ahead of.
Solana's structural problem
Solana's vulnerability is baked into its design. The Ed25519 signature scheme puts each wallet's public key directly inside the on-chain address. There's no hiding. Bitcoin's UTXO model buys some time because unspent, unrevealed keys stay off the radar, but Solana doesn't have that buffer. Every live address is effectively a sitting target.
The fix is coming — but not tomorrow
Both ecosystems are moving. The Ethereum Foundation launched a Post-Quantum Ethereum website in March 2026 and expects L1 protocol upgrades to finish by 2029. That's three years out. Solana is further along on the standard front: validator client developers Anza and Firedancer selected Falcon, a NIST-approved post-quantum signature scheme, in April. The Solana Foundation says the migration is well-researched, understood, and ready to deploy when needed.
Project Eleven maps three Q-Day scenarios — optimistic 2030, moderate 2033, pessimistic 2042 — assuming steady year-over-year improvement in quantum hardware and no sudden breakthroughs. The report doesn't predict panic tomorrow, but it makes clear the window for action isn't infinite.
