Glassnode co-founder Rafael Schultze-Kraft reported that 6.26 million BTC, representing 31.2% of the total supply, are held on addresses with exposed public keys. This share has returned to 2016 levels, rising from 24.8% in early 2021. Experts warn that such addresses could theoretically be vulnerable to future quantum computing attacks.
Of the total exposed amount, 4.33 million BTC are linked to address reuse, while 1.94 million BTC are exposed due to specific script types, including 1.71 million BTC in P2PK format. This figure includes 1.1 million BTC attributed to Satoshi Nakamoto and 222,000 BTC associated with Taproot.
Centralized exchanges show varying levels of exposure. Binance and Robinhood hold 83% and 100% of their balances in such addresses, respectively, while Coinbase holds 10%. Among institutional custodians, Grayscale's exposure reaches 49%, whereas government holdings in the US, UK, and El Salvador currently contain no vulnerable assets.
Since May, the volume of exposed BTC has increased by 222,000 units, with 123,000 of those attributed to centralized platforms. Currently, 57% of exchange balances are held on addresses with exposed public keys, compared to 55% in May and 39% in early 2021. Schultze-Kraft noted these figures do not constitute a risk or security rating.
