[noise] Notes and thoughts from RWC2017

[Jason A. Donenfeld]

On Mon, Jan 16, 2017 at 6:53 AM, Trevor Perrin <trevp at trevp.net> wrote:
> They're doing Noise_XK_secp256k1_ChaChaPoly_SHA256, so this introduces
> a new pattern and a new curve into use.

I'd suggest not adding this old curve the specification...

>
> They specify symmetric-key update in the transport phase.  If people
> are going to keep wanting this we might consider saying something
> about it in the Noise spec.

Is this the ratcheting/key-rotation we had in earlier specs but
removed later on?