BitBo data, 32.4% of all Bitcoin has not moved in the past five years, while 16.8% has remained dormant for more than a decade

How much of this supply is lost, inaccessible, or simply being held long-term remains unresolved, but Check warned that these unmoved coins would be the first targets if quantum computers crack Bitcoin’s current signature schemes

Bitcoin currently relies on elliptic curve cryptography via ECDSA and Schnorr signatures, both of which are vulnerable to Shor’s algorithm once a sufficiently advanced quantum machine is built.

While the U.S. National Institute of Standards and Technology has already approved several quantum-resistant signature schemes, including those referenced in Bitcoin Improvement Proposal 360, adopting such standards requires community-wide agreement.

Bitcoin could adopt post-quantum standards long before a machine capable of breaking SHA-256 becomes viable.