Re: [saag] Revision of "Attacks on Cryptographic Hashes in Internet Protocols"

[Andrey Jivsov <[e-mail]>]

On 11/14/2012 04:39 PM, Paul Hoffman wrote:
>
> On Nov 14, 2012, at 4:33 PM, Andrey Jivsov <[e-mail]> wrote:
>
>> On 11/14/2012 03:42 PM, Paul Hoffman wrote:
>>> On Nov 14, 2012, at 3:35 PM, Andrey Jivsov <[e-mail]> wrote:
>>>
>>>> On 11/14/2012 02:33 PM, Paul Hoffman wrote:
>>>>> On Nov 14, 2012, at 1:40 PM, Andrey Jivsov <[e-mail]> wrote:
>>>>>
>>>>>> SHA-2 is well-supported today, but there are no solid reasons why SHA-3 will not be supported equally well in the future.
>>>>>
>>>>> In that future, we can re-look at support for it in IETF protocols. For now, algorithm agility might be sufficient.
>>>>
>>>> I would agree, but the document such as RFC 4270 influence the future. If the message it sends is that the SHA-3 is an odd bifurcation in the SHA line, SHA-3 won't gain critical mass.
>>>
>>> If we have suggested that in the draft, we should change the text. Can you say where you got that feeling?
>>
>> "However, the authors do not believe that any push to start using SHA-3 is warranted at any time soon."
>
> We disagree that that sentence indicates "that the SHA-3 is an odd bifurcation in the SHA line".
>
> --Paul Hoffman
>

OK Paul, I noted this :-). I would not read it that way, but some people 
might. The Internet will keep your reply as a proof to those.

Nonetheless... I would prefer to see some language suggesting that the 
hash transition issue may be more urgent because of the time lag in some 
cases (described in my previous email).

Re-phrasing my earlier deployment concerns, let me observe that the hash 
algorithm agility/preferences is an elusive thing in general. In 
general, we sign persistent data structures that will be processed by 
entities we may not know anything about. Thus, we cannot gather 
capability preferences from entities who will be performing the 
verification. The only reliable solution is to (universally) deploy 
"read" support and then enable the "generation" of the new data structures.

Thank you.