Re: [TLS] Issue 56: AES as MTI

Chris Newman <Chris.Newman@Sun.COM> Fri, 14 September 2007 19:44 UTC

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Date: Fri, 14 Sep 2007 12:45:51 -0700
From: Chris Newman <Chris.Newman@Sun.COM>
Subject: Re: [TLS] Issue 56: AES as MTI
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To: Eric Rescorla <ekr@networkresonance.com>, "Yee, Peter" <pyee@rsasecurity.com>
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As far as I can tell, the real-world MTI for SSL/TLS as deployed is RC4.  I 
dislike it when the real world MTI and the specified MTI differ and the 
specification fails to explain the difference.

It's my belief that AES-CBC is more likely to result in future alignment of the 
real-world MTI and the specified MTI than 3DES and thus I support a change from 
3DES to AES as MTI.   I would also support a change from 3DES to RC4 as MTI 
despite some concerns about the cryptographic longevity of that cipher.

                - Chris

Eric Rescorla wrote on 9/12/07 16:26 -0700:

> At Wed, 12 Sep 2007 19:27:17 -0400,
> Yee, Peter wrote:
>>
>> Just AES in general or a specific key size and mode?  I'd generally
>> favor the move, although I recognize that AES will probably be slower
>> than RC4 so there will be those who would resist the move.  Despite
>> that, I'd be in favor of AES-GCM as MTI as it's a whole lot better
>> than 3DES_EDE_CBC.
>
> The current algorithm is 3DES_EDE_CBC. I would imagine we would use
> AES_128_CBC. It's a much easier substitution than GCM and most
> TLS stacks already support AES-CBC.
>
> -Ekr
>
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