Which Bitcoin Wallets Are at Risk From Quantum Computers? 6.9 Million BTC Have Exposed Keys

Google Quantum AI’s March paper found about 6.9 million Bitcoin in addresses where the full public key is already visible on-chain, exposed to what researchers call an at-rest attack.

Every standard Ethereum account publishes its public key the first time it signs a transaction, and most active balances already have.

Taproot outputs, Bitcoin’s newest common format since November 2021, put the public key on-chain by design and carry the exposure from creation.

1.7 Million Bitcoin Locked in Keys Nobody Can Move UVL / Shutterstock.com Coinbase’s Independent Advisory Board on Quantum estimates about 1.7 million Bitcoin across roughly 20,000 early P2PK keys are Satoshi-era or otherwise lost.

No deadline risks theft by whoever builds the first capable quantum computer, and 1.7 million coins arriving on exchanges at once.