Subject: [Cfrg] Document shepherd review of draft-irtf-cfrg-re-keying-12

From: Alexey Melnikov <[email-masked]>
Date: Sun, 5 Aug 2018 13:41:36 +0100

Hi Stanislav,

I think the document is in a good state and is ready for IRSG review. I
have only a few minor questions/comments:

3.  Basic Terms and Definitions

   V*      the set of all bit strings of a finite length (hereinafter
           referred to as strings), including the empty string;
           substrings and string components are enumerated from right to
           left starting from one;

The last part of the sentence after the ; - is it needed and why is it
important for this document?

   Int_s: V_s -> Z_{2^s}    the transformation that maps a string a =
           (a_s, ... , a_1) in V_s into the integer Int_s(a) = 2^{s-1} *
           a_s + ... + 2 * a_2 + a_1 (the interpretation of the binary
           string as an integer);

For all other transformations you have human readable definition, but
not for this one. Can one be added? I think it would help document
readability.

In Section 4 (on page 7):

   If the adversary has access to the data processing interface the use
   of the same cryptographic primitives both for data processing and re-
   keying transformation decreases the code size but can lead to some
   possible vulnerabilities.

This text begs for further explanation or for a reference. Can something
be added here?

5.4.  Exploiting Additional Entropy on Re-keying

Use of the word "exploiting" seems odd/unusual here. Maybe not a
problem, but I think just changing this to "use" or something similar
would read more naturally. This might be a good question for native
English speakers :-).

Best Regards,
Alexey

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From: "Stanislav V. Smyshlyaev" <[email-masked]>
Date: Sun, 5 Aug 2018 15:59:46 +0200

Dear Alexey,

Thank you very much for your review! All comments look very reasonable;
addressing them will certainly improve the document.

I’m on my vacation until the middle of August - so if you don’t mind, I’ll
address these comments by the 20th of August.

Best regards,
Stanislav

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From: "Stanislav V. Smyshlyaev" <[email-masked]>
Date: Fri, 17 Aug 2018 17:53:46 +0300

Dear Alexey,

We've posted a new version of draft-irtf-cfrg-re-keying (
https://tools.ietf.org/html/draft-irtf-cfrg-re-keying-13), trying our best
to address all your comments.

Thank you very much again!

Kind regards,
Stanislav