Coinbase Report Warns of Potential Quantum Exposure for Millions of BTC

Coinbase's Quantum Advisory Council has published a report on post-quantum migration and its potential impact on Bitcoin. The report estimates that around 7 million BTC may face future quantum exposure due to legacy address formats, address reuse, and exposed public keys.

The risk is not immediate, as the report focuses on long-term planning for a world with powerful quantum computers that could potentially threaten current public-key cryptography. Coinbase's advisory council suggests possible mitigations, including migration deadlines, tools based on zero-knowledge proofs, and mechanisms like an 'Hourglass' withdrawal rate limiter.

The debate surrounding this issue touches on the treatment of old coins, lost coins, and inactive holders in case a future cryptographic migration becomes necessary. The report's authors emphasize that any migration would be complicated and require broad consensus, careful engineering, and strong social coordination.