Crypto investor Nic Carter highlighted a hypothetical quantum attack scenario where a hostile actor could recover keys to dormant Bitcoin. He warns that while quantum fixes could protect Bitcoin, legitimate owners unable to migrate or prove prior control might risk lockout. Glassnode's May 20 analysis identified 6.04 million BTC, or 30.2% of then-issued supply, with public keys already exposed. Security researcher Jameson Lopp estimated that about 2.6 million exposed BTC might be unable to migrate. Bitcoin Improvement Proposals (BIP) 360 and 361 are exploring new output types and restrictions on legacy signatures to address these risks, with Google setting a precautionary migration deadline of 2029 for its own quantum research.