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Tyypsyesterday at 4:34 AM2 repliesview on HN

Just a little selections of recent attacks on a few post quantum assumptions:

Isogenie/SIDH: https://eprint.iacr.org/2022/975

Lattices: https://eprint.iacr.org/2023/1460

Classical McEliece: https://eprint.iacr.org/2024/1193

Saying that you can trust blindly PQ assumptions is a very dangerous take.


Replies

tptacekyesterday at 2:50 PM

I don't think you said (or cited) what you think you said.

Leaving aside that you actually didn't cite a lattice attack paper, the "dual attack" on lattice cryptography is older than P-256 was when Curve25519 was adopted to replace it. It's a model attack, going all the way back to Regev. It is to MLKEM what algebraic attacks were (are?) to AES.

You know you're in trouble in these discussions when someone inevitably cites SIDH. SIDH has absolutely nothing to do with lattices; in fact, it has basically nothing to do with any other form of cryptography. It was a wildly novel approach that attracted lots of attention because it took a form that was pin-compatible with existing asymmetric encryption (unlike MLKEM, which provides only a KEM).

People who bring up SIDH in lattice discussions are counting on non-cryptography readers not to know that lattice cryptography is quite old and extremely well studied; it was a competitor to elliptic curves for the successor to RSA.

With that established: what exactly is the point you think those three links make in this discussion? What did you glean by reading those three papers?

ramchipyesterday at 8:36 AM

He's obviously not saying that you can "trust blindly" any PQ algorithm out there, just that there are some that have appeared robust over many years of analysis.

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