Subject: [tcpinc] We need MTI symmetric algorithms too!

From: Daniel B Giffin <[email-masked]>
Date: Tue, 24 Oct 2017 11:08:18 -0700

Somehow we overlooked this: the tcpcrypt document does not
currently mandate that implementations support any
particular symmetric (AEAD) algorithms.

We need to make something mandatory-to-implement, of course,
in order to ensure that compliant implementations can talk
to each other.

We propose this disposition for the three algorithms
currently specified for tcpcrypt:

     MUST: AES128-GCM
   SHOULD: AES256-GCM
   SHOULD: CHACHA20_POLY1305

This is the arrangement TLS 1.3 uses as well.

Please comment as soon as possible if you have any concerns
with this approach.

Thanks,
daniel