Glassnode has published a new report quantifying Bitcoin’s quantum exposure, finding that 30.2% of the issued supply — roughly 6.04 million BTC — rests in addresses whose public keys are already visible on-chain. This measurement converts a long-running theoretical concern into a concrete supply figure. A quantum computer capable of breaking elliptic-curve cryptography could potentially derive private keys from those exposed public keys, putting those coins at risk.
The exposure is driven by two distinct factors. Structural exposure accounts for 1.92 million BTC (9.6% of supply), stemming from older script formats such as pay-to-public-key outputs that inherently reveal the public key at rest. The larger portion — 4.12 million BTC (20.6%) — is classified as operational exposure, linked to address reuse, partial spending, and certain custody behaviors. Unlike structural exposure, this segment reflects how holders actually use their wallets. Glassnode emphasizes that headline framing can be misleading: only the 20.6% operational slice is tied to reuse and spending habits, not the entire 30.2%.
Address reuse is the key behavioral risk. When a user spends from an address, the public key becomes visible on the blockchain. If new funds are subsequently received at that same address, the entire balance becomes exposed at rest. Wallet hygiene — using fresh addresses for each transaction — keeps public keys hidden until a spend, limiting the attack surface. Custodians and exchanges, which manage large aggregated balances, also contribute to the operational bucket.
The debate coincides with comments from Cardano co-founder Charles Hoskinson, who argued that Bitcoin’s dominance could be at risk not just from the technology itself, but from governance limitations that make upgrades extremely difficult. He noted Bitcoin has survived many pressures but characterized quantum computing as the next major test. Hoskinson claimed that if the network’s conservatism prevents timely adaptation, its market position could erode. He contrasted this with Cardano’s on-chain governance, which could allow a community-led transition away from vulnerable cryptographic primitives. Hoskinson also referenced an upcoming Cardano upgrade expected to deliver significant performance improvements, underscoring the need for active management during large-scale changes.
The quantum discussion remains a long-horizon conversation rather than an immediate price catalyst. Bitcoin traded near $64,615 as the news circulated, with the Fear & Greed Index at a fearful 26. Developers are already exploring migration paths like the BIP-360 proposal for quantum-resistant outputs. Still, the intersection of quantitative risk data and governance concerns may intensify focus on network resilience planning.
