Bitcoin Quantum Vulnerability Insights from Glassnode

So, Glassnode just dropped a fascinating report about how Bitcoin's supply is at risk from quantum computing. They took a stab at figuring out how many coins could get hit by potential quantum attacks, and the results are pretty shocking. Over 30% of Bitcoin has its public key exposed on-chain, making them prime targets for quantum threats! And get this, centralized exchanges hold about 40% of those at-risk Bitcoins! What’s also wild is that even taproot addresses aren’t safe since their keys are public as well. If you're curious, you can check out the full Glassnode report here: https://insights.glassnode.com/measuring-bitcoins-quantum-exposed-supply/ And there are some other reports you might find useful: https://chainquery.com/reports/quantum-exposure https://chainquery.com/reports/quantum-quarterly/baseline_2026.pdf

This was all over the internet 5 days ago, it was not a shock for me because I know many people have exposed their public keys to the public, but they do not know. It is true that exchanges are victims because they are using just one bitcoin address for individual and they are spending from the addresses while their customers keep depositing bitcoin to the address frequently. Quantum computers are threat than we think, it is better bitcoin developers do something about it.

No it's not theoretical, quantum chips and computers are actual thing, not some mambo jumbo. It would be to late them. You can't decide to fix the wholes in ship that is already sunk on the bottom of the sea.

QC's existing and them being powerful enough to attack SHA256d are 2 very different things. Compared to current computers, right now QC's are at the technology level that mainframe computers were in the 1950's. eg, yes they exist BUT they have several magnitudes of performance increases to go before they are an actual threat. Unlike classic computers, they do not scale just by adding more hardware. The problems of maintaining coherence between qubits and error correction as more are added is almost exponential. Speaking of early mainframes, even the simplest of them filled several large rooms - same as QC's do today. Blackhat's do not and will not have the resources to access them for at least several more decades. As has been repeatedly stressed here, BTC is far down on the list of hacker targets. The main ones will be the global financial systems.

There is another interesting new report from Chainquery website showing Bitcoin quantum exposure. According to this report 5,071,264 Bitcoin is currently at risk, and that is ~25.3% of circulating supply! 1,063,006 coins are always exposed, and 4,008,258 coins are reuse-exposed. Every new taproot output is exposed by design, and that probably means all addresses connected with Silent Payments.  https://chainquery.com/reports/quantum-exposure https://chainquery.com/reports/quantum-quarterly/baseline_2026.pdf

Good thread - and thanks dkbit98 for pulling in our updated numbers, those are correct as of snapshot 2026-06-07 (block 952,694). Worth laying out how the published measurements relate, because they look contradictory and are not: The spread is methodology, not error. Ours is the floor by construction: we only count P2SH/P2WSH spends whose revealed redeem script actually contains a pubkey-bearing opcode. Glassnode counts more early-era output types in their structural bucket (their P2PK figure is ~1.1M BTC vs our 853K; we are comparing notes on that delta). The conservative rule counts every spent-from script hash. Real exposure sits inside the band. NotFuzzyWarm - no argument on the hardware timeline. No CRQC exists, error correction scales brutally, and serious estimates run 10-30 years. Our report says exactly that. The reason the measurement still matters today is the other half of the data: 79% of the exposed pool is reuse-exposed - coins that would be hash-protected if people stopped reusing addresses. That fix is free, requires no soft fork, and works regardless of when (or whether) the hardware arrives. Preparation, not panic. Full thread with the breakdown here: https://bitcointalk.org/index.php?topic=5585526.0 Weekly snapshots: https://chainquery.com/reports/quantum-exposure