Passkeys

Passwords are over. 🔑 Guides, caveats & code for building with Passkeys and WebAuthn — written for developers.

[Passkeys @usepasskeys]

$passkeys is live

CA : 0x8b835b7e4fb7dca4abceeab613d39d0a392ef2dd

[Passkeys @usepasskeys]

Today's warning is clear: elliptic-curve signatures may not survive mathematical superintelligence. Every exposed public key becomes a target.

Here's the uncomfortable part for us. Passkeys sign with ECDSA on P-256. Same family of math that post is worried about. If someone finds a fast way to recover private keys from elliptic curve public keys, a passkey wallet built the normal way is just as exposed as any other wallet. Face ID doesn't change the math underneath.

We've spent a long time studying where passkeys break. Domain binding, the public key you only get once, authenticators that reject you for no reason. That work made one thing obvious to us: the weak point is never the fingerprint. It's what happens to the key after.

So that's what we're building around.

The passkey's public key won't sit on chain in the open. The wallet only stores a hash of it. Until you actually sign something, there's nothing for anyone to attack, no matter how good their math gets.

When you do sign, that key is done. The wallet rotates to a fresh passkey and the old one never protects funds again. You won't notice. Your device handles it.

And the part we care about most: moving funds will need two signatures. One from your passkey, one hash-based. Hashes don't have the algebraic structure curves do, which is exactly why people are pointing at them as the way out. So even in the worst case, where someone cracks the curve and recovers your passkey's private key, they're holding half a lock. The funds stay put.

WebAuthn was also designed so the algorithm can change later. When post-quantum schemes show up in phones and security keys, the wallet can move to them without asking you to write down twelve words or migrate anything by hand.

None of this is new cryptography. It's existing pieces put together with the assumption that the curve might not hold. We'd rather build for that assumption now than write a migration guide later.

We've been quiet for a reason. More very soon.

[Justin Drake @drakefjustin]

Today I call upon the blockchain industry to calmly begin planning for "bunker mode". My personal recommendation is to set in motion a controlled mass migration of assets to fresh addresses, i.e. addresses whose pubkeys remain hidden behind a hash.

Holders, starting with large and sophisticated ones, should consider moving the bulk of their funds to addresses that have never signed a transaction. And when they do sign one, they should also move remaining funds to a new address (possibly generated from the same seed phrase).

Don't rush. While I believe there is cause for action a rushed migration would do more harm than good. Don't panic either. Moving assets to protected addresses is a simple, preventative step which does not require new cryptography or new wallets.

IMO it is now reasonable to brace for the possibility that ECDSA breaks before qday, in the worst case in months not years. By "break" I mean fast private key recovery (e.g. in one week) on available hardware (e.g. a large GPU cluster).

Recent days have been humbling for human mathematical intuition. Long-held, unquestioned hypotheses have fallen. This includes the n log(n) bound for integer multiplication and the 3SUM conjecture. In hindsight, May's unexpected disproof of the Erdős unit distance conjecture was our warning shot.

Yesterday's OpenAI drop made it clear that mathematical superintelligence is upon us. They say there are weeks where decades happen. We are about to live through weeks where centuries of mathematical progress happen. Could our magic 64-byte ECDSA signatures be too good to be true? Was it just security through obscurity all this time?

Elliptic curves feel especially vulnerable to superintelligence. Curves carry rich structure, with room for fancy tricks like Schoof, Frobenius, pairings. (By contrast, hashes are designed to minimise algebraic structure.)

Separately, as Ewin Tang can attest, an efficient quantum algorithm sometimes foreshadows an efficient classical one. We should be open to the possibility of a classical counterpart to Shor that breaks elliptic curves and RSA at once.

Also noteworthy is the striking under-representation of cryptographic breakthroughs among the 722 mathematical results OpenAI published. I've witnessed first-hand the US government censoring academic quantum cryptanalysis results. Backroom interventionism is my base case.

I urge large, sophisticated actors to lead by example. Project11's "risq list" (bitcoin-risq-list.projecteleven[.]com) is a great tracker of exposed BTC pubkeys. Binance, Bitbank, Robinhood, Bitfinex, and Tether have an opportunity to harden their cold storage. Next month I'll address institutions in London in a live Q&A (forum.ethereuminstitutional[.]org/london-2026).

Again, please do not rush. Wallets holding under 50 BTC enjoy partial cover from "Satoshi's shield", i.e. his 20K exposed addresses that hold 50 BTC each. Load-bearing signers like oracles and L2 security councils should consider rotating ECDSA pubkeys with every signed message and/or multi-signing with a hash-based schemes like SPHINCS.

Exiting bunker mode safely will require post-AI cryptography. My inclination is to go all-in on hash-based cryptography and avoid structured mathematical assumptions entirely, whether from curves, lattices, or isogenies. A single battle-tested hash (e.g. from the SHA or BLAKE families) yields plausible post-AI security.

The Ethereum roadmap on strawmap[.]org fully embraces hash-based cryptography with end-to-end formal verification as a response to the quantum threat. Those timelines must now be revisited and accelerated in light of mathematical superintelligence. I'll be pushing for maximum defensive acceleration.

[Passkeys @usepasskeys]

https://t.co/OUFyYZtm4R

[Passkeys @usepasskeys]

Every passkey is bound to one domain.
Every public key is shown only once.
Every prompt can be rejected.

We know the edge-cases. Now we're building around them.

Something will be revealed🔑

Very soon.

[Passkeys @usepasskeys]

Passwords: something you know.
Passkeys: something you have.

🔑 https://t.co/CrfFP3HCv0

[Passkeys @usepasskeys]

https://t.co/mhLndQ6ja9