Nearly one in ten bitcoins in circulation sits in addresses that could eventually be cracked by a sufficiently powerful quantum computer, according to on-chain analytics from Glassnode. The firm estimates that roughly 10% of Bitcoin's total supply — coins stored in older formats or reused addresses — is structurally exposed to the mathematical threat quantum machines pose to elliptic-curve cryptography. Glassnode is urging the network to adopt quantum-proof solutions, specifically pointing to the BIP-360 proposal as a necessary next step.
Why that number matters
Bitcoin's security currently rests on the difficulty of reversing elliptic-curve digital signatures. A quantum computer with enough stable qubits could theoretically do that in minutes. The 10% figure isn't about coins that are lost or dormant; it's about coins whose public keys have been revealed on-chain — either through address reuse or older payment scripts. That makes them the low-hanging fruit in a post-quantum world.
Glassnode's analysis doesn't name a timeline, but the warning is blunt. Even if a large-scale quantum machine is still years off, the exposure today means the window to patch the protocol is finite.
The fix on the table
BIP-360, short for Bitcoin Improvement Proposal 360, outlines a way to transition the network to quantum-resistant signature schemes. It's not a soft fork you push through in a weekend. The proposal would require broad consensus among miners, node operators, and developers. Glassnode says starting the conversation — and the work — now is the only way to avoid a scramble later.
The firm's language is urgent but not alarmist. It stresses that the risk is real but manageable if the community acts deliberately. No exchange or wallet has been compromised by quantum attacks yet; this is a preemptive warning.
What happens next
BIP-360 isn't active on mainnet. It's still a proposal, and there's no date set for a vote. But Glassnode's data gives proponents a clear talking point: roughly 1.9 million bitcoins are currently in vulnerable addresses. That's about $120 billion at today's prices. The clock isn't ticking loudly, but it's ticking.
