Proposed Bitcoin quantum defenses could protect coins while locking out legitimate owners who cannot migrate or satisfy recovery requirements. Glassnode's May 20 analysis identified 6.04 million BTC, or 30.2% of then-issued supply, with public keys already exposed. A hypothetical transfer of 2.5 million BTC from large early outputs could fit within 10 blocks, but fees, competing traffic and miner decisions would determine inclusion. Draft approaches include safer output types, restrictions on legacy signatures, advance ownership proofs and spending limits. These remain proposals and research concepts, with recovery depending on holders' evidence and adoption of future rules.
