Re: [TLS] draft-sheffer-tls-bcp: DH recommendations

"Blumenthal, Uri - 0558 - MITLL" <uri@ll.mit.edu> Wed, 18 September 2013 16:14 UTC

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From: "Blumenthal, Uri - 0558 - MITLL" <uri@ll.mit.edu>
To: Yaron Sheffer <yaronf.ietf@gmail.com>
Date: Wed, 18 Sep 2013 12:13:48 -0400
Thread-Topic: [TLS] draft-sheffer-tls-bcp: DH recommendations
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Cc: "tls@ietf.org" <tls@ietf.org>
Subject: Re: [TLS] draft-sheffer-tls-bcp: DH recommendations
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I believe that for ephemeral DH 2048 bits is a huge overkill. In fact, 1536 is likely to be an overkill as well. I think 1280 bits would be sufficient for the next few years, and perhaps ECC patents will expire by then? In any case, I'd vote against anything (ephemeral DH-related :) larger than 1536 bits.

TNX!

P.S. It should be obvious that PFS is *far* more important than protecting one session key.
--
Regards,
Uri               <uri@ll.mit.edu>;



On Sep 18, 2013, at 10:27 , Yaron Sheffer <yaronf.ietf@gmail.com>; wrote:

> Hi Michael,
> 
> please see my mail message that started this thread, way back on Sunday :-)
> 
> http://www.ietf.org/mail-archive/web/tls/current/msg09903.html
> 
> Thanks,
> 	Yaron
> 
> On 09/18/2013 05:21 PM, Michael Ströder wrote:
>> On Wed, 18 Sep 2013 13:07:58 +0300 Yaron Sheffer <yaronf.ietf@gmail.com>; wrote
>>> There are multiple issues
>>> with MODP DH in TLS (performance is just one of them).
>> 
>> Could you please elaborate on this.
>> 
>> Ciao, Michael.
>> 
>> 
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