Stanford’s Dan Boneh warns quantum computers could crack Bitcoin and Ethereum sooner than expected

A paper published in March 2026 by Google Quantum AI, co-authored by Dan Boneh and Ethereum researcher Justin Drake, revises previous projections for how much quantum firepower would be needed to crack the elliptic-curve cryptography underpinning Bitcoin and Ethereum transactions. The new estimate: roughly 1,200 to 1,450 logical qubits and tens of millions of Toffoli gates could be sufficient to break the secp256k1 discrete logarithm problem. Earlier estimates often placed the requirement at several thousand logical qubits. When you send Bitcoin, your public key gets exposed on the network during the roughly 10-minute window before the transaction is confirmed in a block. A sufficiently powerful quantum computer could, in theory, derive the private key from that exposed public key and redirect the funds before the block is finalized. An estimated 6.9 million BTC sit behind already-revealed public keys, meaning those coins are vulnerable even without an active transaction. Millions of ETH face the same problem. During an August 2026 cryptocurrency lecture, Boneh stressed that the industry needs to start preparing now, but with surgical precision rather than panic. A rushed migration...