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Europol Warns Crypto Wallets Are 'Primary Risk' for Quantum Attacks
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Europol Warns Crypto Wallets Are 'Primary Risk' for Quantum Attacks

Decrypt covers two Europol reports — "Quantum Computing and Cryptocurrencies" (European Cybercrime Centre) and "Harvest Now, Decrypt Later" (with University Carlos III of Madrid) — warning that exposed wallet public keys, not blockchain hash functions, are the primary quantum attack surface for crypto, and that TLS, SSH, and OpenPGP are susceptible to retrospective decryption once quantum computers mature. It details a "just-in-time" attack where a quantum computer derives a private key during the brief window between a transaction broadcasting its public key and confirmation, cites NIST's post-quantum deprecation schedule (phase out classical public-key crypto by 2035), and notes ~30% of BTC supply already has exposed public keys with pre-emptive migration as the only remedy.

TL;DR Europol warns exposed wallet public keys, not blockchain hashing, are crypto's main quantum-attack risk, and flags harvest-now-decrypt-later threats to TLS/SSH/OpenPGP ahead of NIST's 2030/2035 post-quantum deprecation deadlines.
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What it is

Two Europol reports (with EC3 and Spain's University Carlos III of Madrid) on quantum risk to crypto and encrypted protocols. The analysis below covers the concrete figures and operational detail the existing summary omits: the cost of fixing Bitcoin, the hardware timeline, and the expert probability estimate behind the urgency.

Preconditions / Affected

  • Bitcoin specifically: 6.04 million BTC (30.2% of supply) already has exposed public keys on-chain, per Glassnode (May figure cited by Europol) — these cannot be retroactively secured.
  • TLS, SSH, OpenPGP sessions are vulnerable to "harvest now, decrypt later" depending on configuration and key management; Europol states there is "currently no clear evidence" this is being exploited at scale today, with government and confidential business communications as the most plausible targets given the resources required.

What to do

The report quantifies why Bitcoin can't simply "upgrade":

  • NIST-standardized post-quantum signatures are 10–120x larger than ECDSA signatures Bitcoin uses now, which would overload block space, raise fees, and slow confirmations.
  • A cited 2024 study estimates migrating every unspent transaction output to quantum-safe signatures would cost at least 76 days of cumulative network downtime, or ~300 days if confined to 25% of block capacity.
  • For already-exposed keys, the only remedy remains pre-emptive migration of funds to new wallets — there is no after-the-fact fix.

Hardware timeline cited to gauge urgency:

  • IBM targets a fault-tolerant quantum computer by 2029; Microsoft gives the same date.
  • A 2025 survey of 32 experts put the odds of a quantum machine breaking RSA-2048 in 24 hours within the next decade at 28%–49%.
  • Google (March) and an AI-assisted competition (September) both lowered the estimated resources needed to attack Bitcoin's elliptic curve cryptography — i.e., the attack is getting cheaper, not more expensive.

Industry response already underway, per the report: Coinbase's quantum advisory council urged migration work starting in June; Ripple and the Stellar Development Foundation have published migration roadmaps; nine firms (including BlackRock, Coinbase, Strategy) pledged $15M over three years in July for Bitcoin security research including quantum defenses. Europol is pushing for an EU Commission-led working group (with ENISA and the EU AML Authority) to brief policymakers.

Caveats

Europol explicitly states "cryptocurrencies will not collapse due to quantum computing" — this is a proactive-defense recommendation, not an imminent-collapse warning. The harvest-now-decrypt-later threat to TLS/SSH/OpenPGP has no confirmed large-scale exploitation evidence yet; risk is described as plausible and configuration-dependent, not demonstrated in the wild.

Organisations named here

  • ENISA
  • EU Anti-Money Laundering Authority
  • EU NIS Cooperation Group
  • European Cybercrime Centre
  • Europol
  • Harvest Now, Decrypt Later
  • just-in-time attack
  • Q-Day
  • University Carlos III of Madrid

Technologies named here

  • Glassnode
  • Bitcoin
  • Cryptocurrency wallets
  • NIST post-quantum cryptography standards
  • ECDSA signatures
  • Coinbase's quantum advisory council
  • RSA-2048
  • IBM quantum computing roadmap
  • TLS
  • SSH
  • OpenPGP
  • ECDSA
  • NIST

Techniques named here

  • Public-key derivation of private key via quantum computer
  • Harvest now, decrypt later
  • Just-in-time quantum attack

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