Re: [kitten] WGLC on draft-ietf-kitten-aes-cts-hmac-sha2-06

Jeffrey Altman <> Thu, 09 April 2015 19:07 UTC

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Date: Thu, 09 Apr 2015 15:06:34 -0400
From: Jeffrey Altman <>
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Subject: Re: [kitten] WGLC on draft-ietf-kitten-aes-cts-hmac-sha2-06
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Thank you for performing this important review.   The questions you have
raised are significant.   Do we have independent review from trusted
cryptographers?  I'm not one so will not try to review the math.

On 4/8/2015 6:48 PM, Greg Hudson wrote:
> On 04/08/2015 05:26 PM, Benjamin Kaduk wrote:
>> Hmm.  I don't really want to propose removing test vectors to replace them
>> with new ones, but could we add some additional test vectors which do
>> possess the desired properties?  (I.e., that the Kc and Ki are listed in a
>> previous test vector from base key and usage, or that they are test
>> vectors starting from base key.)
> I don't think there's anything precious about the currently listed test
> vectors.  If the draft authors possess the base keys they used for the
> encryption test vectors, they can provide them; otherwise they can
> generate new test vectors and we can discard the old ones.  Including
> encryption test vectors with missing base keys just seems frustrating to
> an implementor.

My personal opinion is that the last call should not complete
successfully if it is not possible to verify all of the test vectors.

It would also be my preference that there be two interoperable
implementations before the working group approves the document.


Jeffrey Altman