[CFRG] Re: Per-KEM security considerations: drafts received, and a two week comment period

["D. J. Bernstein" <[e-mail]>]

> NTRU+ currently achieves the fastest performances among the submitted
> KEMs at comparable security levels.

For example, https://bench.cr.yp.to/results-kem/amd64-phoenix.html
reports median 13754+18706+23207 = 55667 cycles for keygen+enc+dec for
ntruplus768 on Zen 4, compared to 26532+25792+27032 = 79356 cycles for
mlkem768 on the same machine, or 163456+20624+38056 = 222136 cycles for
ntruhps2048677 on the same machine.

Note also that there's a known patent claim (by Zhao) regarding ML-KEM.
BCP 79 states a preference for "technologies with no known IPR claims".

The chairs allowed a "last call" on a more clearly dangerous combiner
option whose rationale is a smaller cycle-count difference than this. It
would be unfair for the chairs to remove ntruplus from an adoption call.

To be clear, I'm opposed to the idea that CFRG should end up supporting
any option that can show any win in any performance metric. But that's
the sort of question that should be decided by CFRG _after_ adoption of
the topic, rather than having options removed now based on snap
judgments by the chairs.

---D. J. Bernstein


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