Ethereum now has a date for surviving quantum computers. The Ethereum Foundation’s Protocol Cluster wants full post-quantum security across the execution, consensus and data layers by December 2029 — and it is treating that as a fixed deadline, not a research goal. The plan came out alongside priority rankings for the next upgrades, published on September 7 and reported by The Block on September 8.
For most holders, the headline sounds abstract. It isn’t. A post-quantum migration is not something that simply happens to your coins in the background: at some point, wallets and users will have to act. The people best placed for that moment are the ones who hold keys they can actually move.
Quantum risk isn’t a reason to panic. It’s a reason to keep keys you can move.
Key facts
- The Ethereum Foundation Protocol Cluster targets full post-quantum security across Ethereum’s execution, consensus and data layers by December 2029, treated as a fixed deadline.
- For the Hegotá upgrade, 9 protocol teams and experts gave 397 grades across 62 EIPs; 28 proposals were declined.
- Two “must ship” proposals lead Hegotá: EIP-7805 (FOCIL, fork-choice enforced inclusion lists) and EIP-8141 (Frame Transactions, native account abstraction).
- Glamsterdam is due on Ethereum mainnet in Q4 2026; full quantum resistance is planned for “L*”, the fifth fork after Glamsterdam, implying about 7.2 months between forks.
- The Foundation plans for “Q-day” as early as 2030, notes that credible estimates put it later, and will reassess the plan by January 2027.
What did the Ethereum Foundation announce on September 8?
The Ethereum Foundation’s Protocol Cluster set December 2029 as the deadline for making Ethereum fully quantum-resistant across its execution, consensus and data layers, and ranked which proposals should ship in the Hegotá upgrade to keep that schedule. The Block reported the plan on September 8, 2026, a day after the rankings were published.
The Hegotá rankings
Nine protocol teams and experts handed out 397 grades across 62 Ethereum Improvement Proposals; 28 were declined. Two landed in the “must ship” tier. EIP-7805, known as FOCIL (fork-choice enforced inclusion lists), forces blocks to include valid public transactions, strengthening censorship resistance. EIP-8141, Frame Transactions, brings native account abstraction, including custom signature schemes and sponsored gas. The “expected to ship” tier includes EIP-8369, EIP-8250 and EIP-8272. The Defiant described the outcome as a narrower scope for Hegotá.
The fork calendar
Glamsterdam is due on mainnet in Q4 2026. After that, the minimum viable post-quantum milestone is a fork labeled “J*”, and full resistance arrives at “L*”, the fifth fork after Glamsterdam. Hitting December 2029 that way implies roughly 7.2 months between forks on average — a demanding pace for a network of Ethereum’s size.
The Foundation framed the urgency plainly. Paraphrasing its statement: shipping post-quantum readiness early is the secure choice, and it signals that Ethereum intends to last 50, 100 or 1,000 years.
What is Q-day, and is my ETH at risk today?
Q-day is the point when quantum computers can break the digital signatures that protect crypto accounts today. The Ethereum Foundation plans for it as early as 2030 while noting that credible estimates put it later, and it will reassess by January 2027. Your ETH is not at quantum risk today; the deadline exists so the fix lands before the threat does.
Why it matters at all: your address is derived from your public key, and the public key is derived from your private key. Classical computers can’t run that math backwards. A sufficiently powerful quantum computer, in theory, could get from a public key to the private key. The key point for users is when your public key becomes visible.
Exposed public keys, in plain words
On most common address types, an address that has only ever received funds shows the world a fingerprint of the public key, not the key itself. The moment an address sends a transaction, its public key is revealed on-chain for good. On Ethereum, a regular account keeps the same address for life, so any account that has ever sent a transaction has an exposed public key. On bitcoin, where wallets generate fresh addresses routinely, reuse is what keeps keys exposed.
What should self-custody users do now?
Nothing dramatic — just good hygiene that also happens to be quantum-friendly. None of these steps require predicting when Q-day arrives:
- Avoid address reuse where you can. Use a fresh receive address for each incoming payment on chains and wallets that support it.
- Keep your backup usable. A seed you can’t find, or a device you can’t unlock, is a problem the day a migration needs a signature from you.
- Watch your wallet vendor, not social media. A real migration will be announced through official wallet and protocol channels. “Quantum upgrade” links in DMs are a scam template waiting to happen.
- Understand where your coins live. Our cold storage guide covers hardware, paper and metal backups and what each is good for.
This is also where EIP-8141 matters to ordinary users. Account abstraction with custom signature schemes is the kind of mechanism that could let an account switch to quantum-safe signatures without moving funds to a brand-new address. It is not a finished migration plan — but it is the plumbing one would need.
The migration will need a signature from you. Make sure you can still give one.
What this means for swap users
A post-quantum roadmap doesn’t change how swaps work today, but it rewards the same habits non-custodial swapping already builds. With SwapZilla there’s no account and no stored balance: each swap pays out to an address you choose, so you can use a fresh receive address every time and keep the output in a wallet whose keys you control. When wallets start offering migration paths, the coins are already where you can act on them — not in a custodian’s queue. If you’re weighing the models, DEX vs CEX vs swap aggregator lays out who holds the keys in each.
Market context, not a signal: on September 8, ETH opened near $2,490 and bitcoin opened at $79,094, down 1.6%, trading around $78,370 at 7:20 a.m. ET, according to Yahoo Finance. For longer-range scenarios, see our Ethereum price outlook — not financial advice.
Final thoughts
December 2029 is ambitious: five forks after Glamsterdam at a demanding pace, with a planning date for Q-day that the Foundation itself says may be early. That caution cuts the right way. For users, the takeaway is small and practical: stop reusing addresses where you can, keep your keys and backups in working order, and hold coins in a form you can move when the upgrade path arrives.