Quantum Computing Won’t Kill Cryptoassets, But It Will Force Them to Evolve

What Europol’s 2026 report tells us about the real quantum risk

Every few months, a headline declares that quantum computers will destroy cryptoassets. A new report from Europol’s European Cybercrime Centre (EC3) offers a more measured view: the threat is real, but it is narrower than the headlines suggest.

A note on terminology: The Blockchain Intelligence Professionals Association (BIPA) recommends using the term “cryptoassets” rather than “cryptocurrencies”, as cryptoassets are not legal tender in the EU and the MiCA Regulation has endorsed the use of the term “cryptoassets” across the EU.

The blockchain itself is safe

The integrity of a blockchain relies on cryptographic hash functions, which quantum computers can only attack with a quadratic speedup (Grover’s algorithm). Breaking a 256-bit hash would still take around 2¹²⁸ operations, which is far beyond foreseeable technology. Both proof-of-work and proof-of-stake networks remain secure, at least in the medium term.

The weak spot is the wallet

Ownership of funds is proven with public-key cryptography, and this is where quantum computers matter. Shor’s algorithm could derive a private key from a public one, allowing an attacker to spend funds without authorisation. Wallets whose public keys are already exposed on-chain are the most at risk, and there is no retroactive fix for them. The only protection is to move funds to new, unexposed addresses before a capable quantum computer exists.

How close is the threat?

Nobody knows for sure. In a 2025 survey cited by the report, 32 experts estimated the chance of a quantum computer breaking RSA-2048 in 24 hours at 5–15% within five years, and 28–49% within ten. This is a medium-to-long-term risk, but one that is close enough to justify acting now.

What can be done

• Incremental upgrades: account abstraction, multi-signature schemes and address rotation reduce exposure, but they only buy time.
• Post-quantum cryptography (PQC): this is the long-term answer. NIST finalised its first standards in 2024, and projects like QRL already show the technology works. Bitcoin and Ethereum have yet to make the switch.
• Quantum security technologies (e.g. QKD): promising in theory, but still experimental, costly and hard to scale.

The real challenge is the transition

The algorithms exist. Deploying them is the hard part. PQC signatures are 10 to 120 times larger than today’s, which strains block space and drives up fees. One study cited in the report estimates that migrating all Bitcoin outputs would need at least 76 days of continuous network capacity, or around 300 days if only 25% of each block is used. Decentralised governance makes coordination slower still, as the SegWit debates showed.

The bottom line

Europol’s message is clear: cryptoassets will not collapse, but their long-term security depends on proactive defence. Developers, wallet providers, exchanges, regulators and users all have a part to play, and the time to start is now.

Source: Europol, “Quantum Computing and Cryptocurrencies – Bridging technical expertise and decision-making”, 2026.