Ledger CTO Charles Guillemet disputes the assessment that only 30% of Bitcoin is vulnerable to quantum computing threats, arguing the metric overlooks critical exposure vectors. While Glassnode data indicates 30.2% of BTC has exposed on-chain public keys, Guillemet warns that unexposed keys may still exist in extended public keys, devices, PSBTs, logs, or backups. Additionally, initiating any transaction exposes the public key before confirmation occurs. Citing Google Quantum AI research, Guillemet noted that theoretical high-speed quantum computers could complete attacks against secp256k1 in approximately nine minutes. He concluded that relying solely on hidden public keys is insufficient for long-term security and stated that Bitcoin will ultimately require migration to post-quantum cryptography to mitigate these risks.