[messaging] Padding

[David Leon Gil]

Just a quick note on an somewhat related  paper that defines
'entropy-restricted' (weaker) analogues of standard indistinguishability
notions:

Kelley and Tamassio, Secure Compression: Theory & Practice:
http://eprint.iacr.org/2014/113

(Their definitions seem weaker than I'd like, however.)

(Somewhat more post-IO.)
 On Jun 26, 2014 12:03 PM, "Michael Rogers" <michael at briarproject.org>
wrote:

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> On 26/06/14 19:57, Michael Rogers wrote:
> > It seems to me that the information leak depends on the observer's
> > prior knowledge about possible message sizes. For example, if the
> > observer knows that the message is either "Yes" or "No" then
> > padding to the next power of two does nothing to conceal the
> > message size (which in turn reveals the content).
>
> Sorry for the self-reply. Putting it in these terms made me wonder
> whether we should aim to minimise the mutual information between the
> input and output distributions.
>
> Cheers,
> Michael
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