Eric Murray writes:
> On Tue, Feb 29, 2000 at 11:14:31AM -0500, Russell Nelson wrote:
> > One could increase the difficulty of decryption by three or four
> > doublings by intermixing random data with plaintext in a message.
> > Here's the least stupid method I can think of: the first character in
> > a message is the start of text (SOT) character. The second character
> > in a message is the end of text (EOT) character. The message itself
> > consists of random data intermixed with plaintext prefixed by SOT and
> > suffixed with EOT. An EOT outside of plaintext stands for itself. An
> > SOT inside plaintext stands for itself. This method can encode
> > arbitrary plaintext. By implication, the random data does not contain
> > an SOT nor EOT.
>
> I assume that you do this before encryption.
Yes.
> Wouldn't compressing the plaintext before encryption have the same effect?
Only if you use a secret compression system. Otherwise the structure
of your compression system still exists as a known plaintext. You
could (probably should) compress your plaintext before running it
through the above algorithm.
The essence of the above algorithm (let's call it BP1, for Buried
Plaintext 1) is to force the decryption trial to be iterated until the
buried plaintext is found. It means that the decryption engine needs
to have the full crypttext available to it. If you can decrypt a
message in N steps, then using BP1 with half random data forces you to
do N*2 steps, where the steps themselves are more complicated. The
storage requirements are higher, as are the data transfer pathways.
--
-russ nelson <[EMAIL PROTECTED]> http://russnelson.com
Crynwr sells support for free software | PGPok | "Ask not what your country
521 Pleasant Valley Rd. | +1 315 268 1925 voice | can force other people to
Potsdam, NY 13676-3213 | +1 315 268 9201 FAX | do for you..." -Perry M.
