[5887] in cryptography@c2.net mail archive
Re: "unbreakable code?" with cash prizes
daemon@ATHENA.MIT.EDU (Michael Paul Johnson)
Wed Oct 13 00:10:50 1999
Message-Id: <4.1.19991012193938.0098ca80@ebible.org>
Date: Tue, 12 Oct 1999 19:42:12 -0600
To: staym@accessdata.com, cryptography@c2.net
From: Michael Paul Johnson <mpj@eBible.org>
In-Reply-To: <3803B85B.2206@accessdata.com>
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At 04:38 PM 10/12/99 -0600, staym@accessdata.com wrote:
>I guess the question is, how much entropy is in your average compressed
>jpeg?
Actually, a jpeg file, especially with heavy lossy compression turned on,
isn't that far from random. It does provide some known plain text in the
stream, though, in the header. This leaks some information which may or may
not be useful in breaking the rest of the message.
[I would also imagine that the fact that the message was in ASCII and
in English probably means that the job of breaking this is doable,
although it might require some tools that no one would care to build
to do it. --Perry]
_______
Michael Paul Johnson
mpj@eBible.org http://ebible.org/mpj
