Re: [Rats] FW: New Version Notification for draft-shaw-rats-rear-00.txt

Henk Birkholz <> Thu, 02 July 2020 16:41 UTC

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To: Thomas Fossati <>, "" <>
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From: Henk Birkholz <>
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Date: Thu, 2 Jul 2020 18:40:44 +0200
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Subject: Re: [Rats] FW: New Version Notification for draft-shaw-rats-rear-00.txt
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Hi Thomas,

On 02.07.20 18:06, Thomas Fossati wrote:
> Hi Henk,
> On 02/07/2020, 15:05, "Henk Birkholz" <> wrote:
>> Hi Thomas,
>> hi authors,
>> please let me start with: I really like what this I-D is about;
>> especially how everything is basically arranged around how to use
>> timestamps and nonces in several specific interactions. The essence
>> here is the qualified data conveyed via restful operations that are
>> used to create Conceptual Messages, such as Evidence or Attestation
>> Results.
>> The fact that all these different types of qualifying data are bound
>> with each other via sequences of restful operations makes the
>> relationship of the sequence diagrams rather complex and renders the use
>> of the qualified data / handles hard to read. At the same time, I am
>> uncertain how to avoid that, though.
>> You managed to get all the semantic relationships into the sequence
>> diagrams themselves. I am quite impressed. But I could only decipher the
>> notation while parsing them with the help of a little cheat sheet that I
>> wrote down on a piece of paper.
>> This topic is intrinsically complex, so - as I already said - I am
>> unable to provide an immediate proposal how to increase readability. The
>> fact remains that this is a very useful -00 I-D. Suffice to say that I
>> would rather have this content in this form than not at all!
> Thank you for your taking the time to parse the document - and making
> the cheat sheet!  Also glad you found the topic interesting.
> Re: readability.  It seemed to us that it would be easier to use a
> top-down approach, presenting the abstract protocol first and then
> giving a number of possible instantiations.  Apparently it didn't work
> as smoothly as expected.  Maybe to lower the barriers to entry we could
> give a short primer at (one of) the next meeting(s)?

Yes, please. I think with floating this document more, we might get some 
additional hints and tips and, of course, feedback on how this currently 
addresses the needs of implementers. I'd encourage to request a slot for 
the upcoming IETF 108 sessions.

>> Coincidentally, more generic versions of your diagrams with respect to
>> the reference interaction models can be found in this editor's version:
>> These diagrams use simpler annotation, but therefore are also way more
>> generic. They match with your more specific semantics, though, and I am
>> very happy about that.
> Thanks for the pointer.  I like the more human-friendly notation.  I'll
> have a look and see if I can make our diagrams look similar.  I'm also
> going to swap our reference to TUDA with the more generic reference to
> your section 7.2 (Uni-Directional Remote Attestation).  When are you
> going to publish the new version?

That sounds great. With respect to submission... yes, we should do a 
submit soon and then another before the submission moratorium, if we are 
able to pull in the expected content about Direct Anonymous Attestation. 
Let me see, if I can do another pass on the relatively fresh and clumsy 
text around the diagrams in section 7, first.

Viele Grüße,


> cheers, thanks!
>> We also struggled a bit with the illustration of the processing of
>> qualified data in TUDA and based on your new I-D we can now try to
>> improve them.
>> Viele Grüße,
>> Henk
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