Re: [TLS] Truncated HMAC recommendation

Eric Rescorla <ekr@networkresonance.com> Mon, 27 November 2006 18:36 UTC

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To: Mike <mike-list@pobox.com>
Subject: Re: [TLS] Truncated HMAC recommendation
References: <456B2FC6.10902@pobox.com>
From: Eric Rescorla <ekr@networkresonance.com>
Date: Mon, 27 Nov 2006 10:36:05 -0800
In-Reply-To: <456B2FC6.10902@pobox.com> (Mike's message of "Mon, 27 Nov 2006 10:34:46 -0800")
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Mike <mike-list@pobox.com> writes:

> I think it would be good to add a recommendation
> that when the truncated HMAC extension is used,
> the amount of padding added for block ciphers
> should be the minimum required.  It seems silly
> to save 10 bytes of MAC data and then add 250+
> extra padding bytes.

I agree with your analysis, but it's not clear why this should go
into the standard.

-Ekr

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