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Re: [TLS] Data volume limits

Brian Smith <brian@briansmith.org> Wed, 16 December 2015 00:00 UTC

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From: Brian Smith <brian@briansmith.org>
To: Watson Ladd <watsonbladd@gmail.com>
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Subject: Re: [TLS] Data volume limits
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Watson Ladd <watsonbladd@gmail.com> wrote:

> The issue is the bounds in Iwata-Ohashai-Minematsu's paper, which show
> a quadratic confidentiality loss after a total volume sent. This is an
> exploitable issue.
>

Please explain in more detail how you got "2^36 bytes" for a nonce size of
96 bits from the Iwata-Ohashai-Minematsu paper [1].

[1] https://eprint.iacr.org/2012/438.pdf

Also, the Niwa-Ohashi-Minematsu-Iwata follow-up paper [2] change things in
any way? In particular, note that it concludes "The new security bounds
improve the security bounds in [11] by a factor of 2^17, and they show that
the security of GCM is actually close to what was originally claimed in
[17,18]."

A factor of 2^17 difference is pretty significant as far as this is
concerned, AFAICT.

[2] https://eprint.iacr.org/2015/214.pdf

Cheers,
Brian
--
https://briansmith.org/

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