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Re: [Tcpcrypt] Initial questions

Joe Touch <touch@isi.edu> Thu, 19 June 2014 17:56 UTC

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Date: Thu, 19 Jun 2014 10:55:58 -0700
From: Joe Touch <touch@isi.edu>
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Subject: Re: [Tcpcrypt] Initial questions
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On 6/19/2014 3:46 AM, ianG wrote:
> On 18/06/2014 22:36 pm, Joe Touch wrote:
>> Comments on your other points:
>>
>> On 6/18/2014 2:15 PM, Sandy Harris wrote:
>>
>> As to the specific algorithms and how many, we probably all agree that a
>> small number of required algorithms is preferable. I think 2 is a good
>> upper bound on the MUST algorithms, though.
>
> Actually, no.  I for one disagree.  There should be one true cipher
> suite [0].

If you have only one, then if (or when) you urgently decide it's 
vulnerable and want an alternate you need to wait for deployment of an 
update (e.g., as happened to TCP MD5). That will undermine the utility 
of a solution.

That's why TCP-AO included two 'must implement' algorithms from the 
start, and why it's important to do so here as well.

Joe

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