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Re: [TLS] Pull Request: Removing the AEAD explicit IV

Eric Rescorla <ekr@rtfm.com> Sat, 21 March 2015 18:58 UTC

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From: Eric Rescorla <ekr@rtfm.com>
Date: Sat, 21 Mar 2015 11:58:06 -0700
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To: Adam Langley <agl@imperialviolet.org>
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Subject: Re: [TLS] Pull Request: Removing the AEAD explicit IV
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Adam, Brian, what would you think of XOR rather than addition?

E.g., generate a per-connection value V and then do:

Nonce = Seq XOR V?

-Ekr


On Thu, Mar 19, 2015 at 1:25 PM, Adam Langley <agl@imperialviolet.org>
wrote:

> On Thu, Mar 19, 2015 at 12:58 PM, Eric Rescorla <ekr@rtfm.com> wrote:
> > Are other people concerned about this issue? I seem to remember this
> > being discussed in the interim and AGL being opposed to this change.
>
> I would phrase it as an extended key to the AEAD and keep the nonce
> the same, but I'm not opposed so starting at a random point in the
> nonce space and counting from there. However, since the AES-GCM AEAD
> is already defined I can see the practical argument for having TLS do
> the nonce masking.
>
>
> Cheers
>
> AGL
>
> --
> Adam Langley agl@imperialviolet.org https://www.imperialviolet.org
>

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