[tcpinc] We need MTI symmetric algorithms too!

Daniel B Giffin <dbg@scs.stanford.edu> Tue, 24 October 2017 18:08 UTC

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Date: Tue, 24 Oct 2017 11:08:18 -0700
From: Daniel B Giffin <dbg@scs.stanford.edu>
To: tcpinc <tcpinc@ietf.org>
Message-ID: <20171024180818.GA82777@scs.stanford.edu>
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Subject: [tcpinc] We need MTI symmetric algorithms too!
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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