Europol says quantum computing won't break Bitcoin but flags exposed wallets
In brief
- Europol's EC3 published two quantum computing reports on October 7, 2026.
- Cryptocurrencies will not collapse due to quantum computing, Europol said.
- Wallets built on public-key cryptography are the 'primary point of exposure,' Europol said.
- An estimated 6 to 6.9 million BTC sit in addresses with exposed public keys.
- Europol recommended phased post-quantum cryptography adoption paired with wallet upgrades.
What the report says about Bitcoin
The primary report is titled "Quantum Computing and Cryptocurrencies – Bridging Technical Expertise and Decision-Making," and a companion report addresses the wider quantum threat to encrypted data. Both build on earlier Europol assessments of quantum technology published in 2023.
The blockchain itself isn't the weak spot. Europol said ledger integrity holds because it relies on hash functions such as Bitcoin's SHA-256, which the agency described as largely resistant to quantum attacks.
"Cryptocurrencies will not collapse due to quantum computing."
That's the headline finding. It isn't the whole picture, though.
Where the exposure sits
So what's actually at risk? Wallets.
According to the report, a sufficiently powerful quantum computer could derive a private key from an exposed public key and sign unauthorized transactions. Europol estimated that approximately 6 to 6.9 million BTC, roughly 30% of Bitcoin's supply, sit in addresses whose public keys have already been exposed.
Those keys can't be secured retroactively. Europol said the only real protection is moving exposed funds to safe wallets before a capable quantum machine arrives.
Migration and coordination
Europol recommended a phased adoption of post-quantum cryptography (PQC) paired with wallet upgrades. It also flagged coordination as a central challenge, and the report's own math shows why: under certain assumptions, it estimated that migrating all Bitcoin UTXOs could require more than 76 days of cumulative processing time. The figure depends on those stated assumptions; it's not a forecast of how long a real migration would take.
Crypto Briefing's own read is that proactive migration shifts much of the responsibility from the protocol to individual users. That's the publication's assessment, not a line from Europol, but it follows from the agency's recommendation that holders move exposed funds themselves.
The protocol holds, per Europol. The open question is how many of those exposed coins get moved, and by whom.
Frequently asked questions
Does Europol think quantum computing will break Bitcoin?
No. Europol's EC3 reports, published October 7, 2026, found that cryptocurrencies will not collapse due to quantum computing. The agency said blockchain integrity holds because it relies on hash functions such as Bitcoin's SHA-256, which it described as largely resistant to quantum attacks.
Which Bitcoin wallets are exposed to quantum attacks according to Europol?
Europol called wallets built on public-key cryptography the 'primary point of exposure.' A sufficiently powerful quantum computer could derive a private key from an exposed public key and sign unauthorized transactions. The report estimated about 6 to 6.9 million BTC, roughly 30% of supply, sit in addresses with already-exposed public keys.
What does Europol recommend to protect exposed Bitcoin?
Europol said the only real protection is moving exposed funds to safe wallets before a capable quantum machine arrives, since exposed keys can't be secured retroactively. It recommended a phased adoption of post-quantum cryptography paired with wallet upgrades, and flagged coordination as a central challenge.
