Blockchain analytics firm Glassnode said on 10 November that 35.4% of Bitcoin’s total supply, or 7.12 million BTC, sits at addresses whose public keys are publicly visible. According to Japanese outlet CoinPost, which relayed the firm’s post on X, these are the keys that a future quantum computer could target.
The finding is theoretical for now. CoinPost reports that no quantum computer able to break Bitcoin’s signature cryptography exists, and that current machines remain below the roughly 500,000 qubits Google estimated would be needed. The outlet says Google made that estimate in March, without giving the year.
What drives the exposure
According to the Glassnode post as described by CoinPost, 25.8% of supply is exposed through address reuse, while 11.6% sits on exchanges. Glassnode says that moving such coins to new addresses would remove the exposure.
The report does not say how much of the 7.12 million BTC is likely lost or dormant, which matters because coins that never move cannot be migrated by their owners. Glassnode’s methodology and data cutoff are also not given.
Proposals under discussion
CoinPost says Coinbase proposed a discussion framework on 13 October for moving to quantum-resistant mechanisms. The exchange reportedly argued for a comprehensive strategy that includes protecting funds whose public keys are already exposed, and said preparation should start before a capable quantum computer is confirmed, because consensus changes and migration take years.
Separately, Bitcoin Core developer Corey Fields proposed three mechanisms on a developer mailing list on 5 November, according to CoinPost. Each would require collateral equal to the amount moved from legacy-format addresses once an attack becomes possible. The aim is to remove the incentive to steal, since a thief could lose the collateral.
It is not known whether either proposal has gained support among Bitcoin developers.
What remains unclear
The account rests on a single outlet, and the original Glassnode post was not reviewed. The source document for the Google estimate is also not identified.
Sources
- CoinPost: グラスノード、ビットコインの35.4％が量子コンピュータの標的になりうると指摘 (2026-11-11)
Sources
- coinpost.jp CoinPost — グラスノード、ビットコインの35.4％が量子コンピュータの標的になりうると指摘 Accessed
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