Kernel ML-KEM implementation plans

[Eric Biggers]

On Mon, Mar 30, 2026 at 06:41:46PM -0500, Ryan Appel wrote:
> Hello all, 
> 
> Looking through the mail archives I see no information on an
> implementation of ML-KEM that has been planned, except for leancrypto
> attempting to make a Key-Agreement Scheme a Key-Encapsulation
> Mechanism.
> 
> Is there a plan to implement a KEM interface at this point? Is this
> something that needs support?  How could someone contribute to this?

We don't add new algorithms preemptively, but rather only when an
in-kernel user comes along.  Otherwise there's a risk that the code will
never be used.

Do you have a specific in-kernel user in mind?  I haven't actually heard
anyone specifically say they need ML-KEM in the kernel yet.

I guess the obvious use case would be WireGuard.  But that would require
a new WireGuard protocol version that replaces X25519 with something
like X25519MLKEM768.  It's going to be up to the WireGuard author
(Jason) to decide whether that's in the roadmap for WireGuard.

Also maybe Bluetooth, though it seems the spec for that is yet to be
defined?

Anyway, point is, before it makes sense to consider possible
implementation strategies, there needs to be a plan to actually use it.

- Eric