Analytics firm Glassnode reports that 7.12 million Bitcoin, representing 35.4% of the total supply, are vulnerable to potential quantum computing threats. This exposure stems from visible public keys on the ledger, which could theoretically be compromised by future quantum machines. Currently, 25.8% of the supply is exposed due to address reuse, while 11.6% is held on exchanges.
Exchange exposure varies significantly, with Glassnode data indicating that 100% of Robinhood's holdings, 85% of Binance's, and approximately 5% of Coinbase's are in exposed addresses. Coinbase CEO stated on October 29 that the company has begun upgrading its custody services to be post-quantum secure. US government holdings show no such exposure.
Moving assets to a fresh address can mitigate this risk for most users. However, approximately 1 million BTC associated with Satoshi Nakamoto have remained unmoved for over 15 years, making them impossible to secure through standard upgrades. Proposals to address these dormant coins include freezing them or implementing optional upgrades, though no activation dates exist.
While the exposed coins are valued at over $500 billion at current market prices, experts suggest that quantum-capable machines are likely 20 to 40 years away. Google noted in March that a machine with under 500,000 qubits could theoretically break current encryption. Next Technology Holding recently authorized the sale or pledge of 5,833 BTC, citing quantum risks.
