Bitcoin's $452 Billion Value Faces Quantum Computing Exposure, Glassnode Reports

Crypto analytics firm Glassnode identified that about 6.04 million Bitcoin – roughly 30 % of the circulating supply and worth more than $452 billion at current prices – are potentially vulnerable to future quantum‑computer attacks. The exposure stems from public keys that are already visible on‑chain, which a sufficiently powerful quantum computer could reverse using Shor’s algorithm.

Glassnode split the at‑rest exposure into two categories. Structural vulnerability affects 1.92 million BTC (9.6% of supply) because certain script types – early Pay‑to‑Public‑Key outputs, legacy multisig and modern Taproot outputs – disclose public keys by design. Operational vulnerability involves 4.12 million BTC (20.6% of supply) where public keys have been revealed through address reuse or custodial practices; about 1.66 million BTC of this share is held on exchanges.

The report notes that government‑held Bitcoin reserves (e.g., in the United States, United Kingdom and El Salvador) show virtually no exposure, as they are stored in secure structures. While the timeline for a quantum attack remains uncertain, Google has projected a “Q‑Day” as early as 2029, prompting discussion of quantum‑safe cryptography migration.

The analysis warns that any future quantum breakthrough could allow attackers to steal exposed coins without waiting for owners to move them, highlighting a significant security challenge for the crypto ecosystem.