Ledger CTO Charles Guillemet questioned the analysis that only about 30% of Bitcoin is exposed to the risk of quantum computing attacks. He emphasized, "According to Glassnode, approximately 30.2% of BTC has its public key exposed on-chain when spent, but public keys can also be exposed in xpub, devices, PSBTs, logs, backups, etc., and are revealed before transaction confirmation when BTC is sent. If sufficiently fast quantum computers emerge in the future, simply hiding public keys will not be enough. Bitcoin will eventually have to transition to a quantum-resistant cryptographic system."
