From: elee9sf@Menudo.UH.EDU
Date: Fri, 23 Apr 93 13:23:15 PDT
To: cypherpunks@toad.com
Subject: RADIO: keys, ham, and subliminal channels
Message-ID: <199304232022.AA29561@Menudo.UH.EDU>
MIME-Version: 1.0
Content-Type: text/plain



> The meaning must still be in clear but you are allowed to send a
> authenticating "signature" in code, as long as the signature 
> contains no information other than authentication itself that was 
> not also transmitted in clear.  That's why autopatch

Hmm... if authenticating signatures can be transmitted, then some
enterprising and patient cryptographers can also transmit messages,
encrypted if desired, back and forth using one of the "subliminal
channel" protocols!

A subliminal channel allows people to communicate by essentially
disguising their true message in the digital signature of the message
they transmit openly.  It would take several exchanges between the two
to transmit a real message, since I recall the subliminal channels
I've looked at allow the transfer of a few numbers at a time, but it
could be done!

/-----------------------------------\
| Karl L. Barrus                    |
| elee9sf@menudo.uh.edu             | <- preferred address
| barrus@tree.egr.uh.edu (NeXTMail) |
\-----------------------------------/