We’ve written about quantum threats to crypto before, often zooming in on Switzerland’s early moves in the space, but lately the topic feels more urgent than ever. Steady progress in AI, computing power, and even energy tech means the long-term risks are no longer just theoretical chit-chat, they’re creeping into mainstream Ethereum discussions.
Vitalik Buterin put it front and centre in a detailed X thread on 12 January 2026. He introduced something he calls the “walkaway test” for the Ethereum protocol. The basic premise is straightforward: Ethereum’s base layer should be secure, functional, and actually useful even if most core developers walked away tomorrow and stopped shipping big upgrades. In other words, the chain should be capable of “ossifying” into a mature, stable state by community choice, without sacrificing what makes it valuable. Vitalik is clear that we shouldn’t stop improving Ethereum, but the goal is to reach a stage where further changes are nice bonuses rather than must-haves for survival.
Top of his seven-point checklist of non-negotiable requirements? Full quantum resistance. He pushes hard for pre-emptive upgrades that would make the protocol cryptographically safe for a hundred years or more. He specifically warns against kicking the can down the road just to gain a bit of short term efficiency, and moving away from vulnerable primitives like enshrined ECDSA is a big part of that picture. This isn’t some distant doomsday scenario, it’s a deliberate maturity milestone.
Quantum resistance has been on the radar for big tech and cryptography folks for years now, all because of the eventual risk from cryptographically relevant quantum computers. Those machines could one day run Shor’s algorithm and break the elliptic-curve signatures that Ethereum (and most of the internet) currently depends on. At the moment, though, real quantum computers are still extremely expensive, massively power-hungry, full of errors, and stuck with only a handful of logical qubits. They’re nowhere near the scale needed to threaten public-key crypto, which keeps them out of reach for pretty much everyone except perhaps a few nation-states.
Expert consensus in 2026 still puts a genuine threat 10–30+ years away for breaking current schemes (a few optimistic or alarmist voices talk late 2020s or early 2030s, but the middle-of-the-road view remains firmly in the decades-out camp).
When quantum threats do eventually materialise, the whole industry will have to adapt, but blockchains have an extra headache thanks to immutability. You can’t just rewrite the ledger without destroying trust, so the solution lies in careful, well-coordinated hard forks for security upgrades. The Merge proved it’s doable when the community gets behind it.
The space is absolutely laser-focused on this right now. NIST has rolled out post-quantum standards, Ethereum researchers are digging into lattice-based signatures, STARKs, account abstraction to phase out ECDSA, and various other approaches (some of which are already seeing action on layer-2 networks). Full protocol-level quantum resistance isn’t deployed on mainnet yet, it’s still several years of research and careful implementation away but the work is moving forward with purpose.
Bottom line: the realistic threat window is likely 10–20 years away at the earliest for most scenarios, and the current push (with Vitalik leading the charge) is all about tackling it long before confidence starts to waver.