Re: [Cfrg] Review of Dragonfly PAKE

"Dan Harkins" <dharkins@lounge.org> Wed, 11 December 2013 22:07 UTC

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Date: Wed, 11 Dec 2013 14:07:09 -0800 (PST)
From: "Dan Harkins" <dharkins@lounge.org>
To: "Trevor Perrin" <trevp@trevp.net>
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Cc: cfrg@ietf.org, "tls@ietf.org" <tls@ietf.org>
Subject: Re: [Cfrg] Review of Dragonfly PAKE
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On Wed, December 11, 2013 11:50 am, Trevor Perrin wrote:
> On Tue, Dec 10, 2013 at 5:35 PM, Dan Harkins <dharkins@lounge.org>; wrote:
[snip]
>>   It makes little sense to negotiate a 256-bit or even a 128-bit
>> cipher or a hash algorithm with a 256-bit or 512-bit digest size
>> when the domain parameter set is fixed to a 1024-bit FFC group.
>> What makes sense is to allow for negotiation of a 4096-bit FFC
>> group or a 256-bit ECC group along with your AES-GCM-128
>> with key derivation using HMAC-256.
>
> It makes little sense to use a 1024-bit FFC group in any circumstances
> because (pardon me, Kevin) - fuck the NSA.

  That certainly is a fashionable pose to strike these days!

  But I brought up binding a 1024-bit FFC to a password because that's
what an RFC with your name on it does. So it makes sense to replace
"the NSA" in your sentence with "Trevor Perrin".

  Dan.