Ledger CTO: The Claim That Only About 30% of BTC Faces Quantum Risk Is Questionable

Odaily reports that Ledger CTO Charles Guillemet has stated that the view that only about 30% of BTC faces quantum computing risk, while the remaining roughly 70% is safe due to public key hash protection, is problematic. Previous Glassnode data shows that approximately 30.2% of BTC has already exposed its spending public key on-chain, but Guillemet points out that this only measures the static state on-chain; unexposed public keys may still exist in xpubs, devices, PSBTs, logs, or backups. At the same time, once BTC initiates a transaction, the public key becomes public before the transaction is confirmed.

Guillemet cites Google Quantum AI research, stating that under the assumption of a high-speed quantum computer that does not yet exist, a relevant attack targeting secp256k1 could be completed in about 9 minutes. Therefore, simply hiding public keys cannot solve the quantum risk, and Bitcoin will ultimately still need to migrate to post-quantum cryptography.