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

Quick Read Google Quantum AI's March 2026 paper found 6.9 million Bitcoin in addresses with publicly visible keys, leaving them exposed to offline quantum attacks.

Taproot addresses expose public keys by design, and any P2PKH address spent from even once permanently publishes its full public key on-chain.

About 1.7 million Bitcoin in lost Satoshi-era keys, worth over $100 billion, cannot migrate to quantum-safe addresses because the private keys no longer exist.

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

1.7 Million Bitcoin Locked in Keys Nobody Can Move 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.