Re: [babel] Babel-MAC: Blake2s is 128-bits by default

[Donald Eastlake <[e-mail]>]

Hi Juliusz,

There having been no further comments and given the extent to the
discussion of this on the WG mailing list, I'm declaring WG consensus
for this minor change.

Thanks,
Donald
===============================
 Donald E. Eastlake 3rd   [phone] (cell)
 2386 Panoramic Circle, Apopka, FL 32703 USA
 [e-mail]

On Thu, Nov 26, 2020 at 2:02 PM Donald Eastlake <[e-mail]> wrote:
>
> Hi Juliusz,
>
> On Thu, Nov 26, 2020 at 7:04 AM Juliusz Chroboczek <[e-mail]> wrote:
>>
>> >> I do not believe that it impacts the security in any way (2^128 ns is
>> >> roughly 10^12 times the age of the universe), but I could be wrong.
>>
>> > Yeah, makes sense, let's keep it at 32 bytes :)
>>
>> Excellent.  I'm therefore going to make the following change in AUTH48:
>>
>>   - in Section 4.1, replace
>>
>>    Every implementation MUST implement HMAC-SHA256 as defined in [RFC6234]
>>    and Section 2 of [RFC2104], SHOULD implement keyed BLAKE2s [RFC7693],
>>    and MAY implement other MAC algorithms.
>>
>>    Every implementation MUST implement HMAC-SHA256 as defined in [RFC6234]
>>    and Section 2 of [RFC2104], SHOULD implement keyed BLAKE2s with 128-bit
>>    (16-octet) digests [RFC7693], and MAY implement other MAC algorithms.
>>
>> I will not change the following text in Section 7:
>>
>>     Ideally, they should have a length of 32 octets (both for HMAC-SHA256
>>     and Blake2s), and be chosen randomly.
>>
>> Donald, are you willing to call consensus on this point?
>
>
> All this has been discussed on the WG mailing list with no objection and there has been some further success but just to be sure, I'd like to wait a couple of days before declaring consensus.
>
> Thanks,
> Donald
> ===============================
>  Donald E. Eastlake 3rd   [phone] (cell)
>  2386 Panoramic Circle, Apopka, FL 32703 USA
>  [e-mail]
>
>>
>> -- Juliusz