Bitcoin about 10% of supply at quantum risk, Glassnode says

Glassnode’s latest on‑chain analysis estimates that just under 10% of the total Bitcoin supply could become vulnerable to a future quantum computer capable of breaking the Elliptic Curve Digital Signature Algorithm (ECDSA) that secures transactions [2]. The vulnerability stems from the fact that many addresses have already revealed their public keys—once a quantum processor can derive the private key from a public key, those coins could be stolen without the owner’s consent.

The risk is not theoretical in the abstract; it is tied to concrete on‑chain behavior. When a Bitcoin address first receives funds, the public key remains hidden behind a hash. Once the address spends, the public key is exposed on the blockchain. Glassnode’s metrics track how often such exposures occur, and the current figure suggests that roughly one in ten bitcoins sit behind an address whose public key is already visible [2]. If a sufficiently powerful quantum computer were built, it could apply Shor’s algorithm to reverse‑engineer the private key, effectively granting an attacker control over those coins.

Developers and the broader Bitcoin community are aware of the issue. Discussions are already underway about migrating to post‑quantum‑resistant signature schemes, which would require a coordinated protocol upgrade and extensive testing to avoid network fragmentation [2]. However, the timeline for practical quantum attacks remains uncertain. Existing quantum hardware has not yet reached the scale or reliability needed to threaten ECDSA, and the transition to quantum‑safe cryptography could be staged well before such capabilities emerge [2].

The structural exposure highlighted by Glassnode underscores a longer‑term security dilemma: Bitcoin’s robustness depends on cryptographic assumptions that may not hold indefinitely. While the immediate market impact is muted—prices continue to be driven by macro factors and trader positioning—the underlying risk could shape future development priorities and community consensus. As quantum research advances, the question remains whether the Bitcoin ecosystem can orchestrate a seamless upgrade or whether the “structurally unsafe” portion will force a reactive scramble to protect a sizable slice of the world’s most valuable digital asset.