At 5:13 PM 11/7/1996, Jim McCoy wrote:
Getting a program to recognize a subliminal message channel is even harder than teaching a human to do so, check out the book Disappearing Cryptography or do a web search for "mimic functions" to see how easy it is to hide messages in text which a program parses as regular English. The other problem is that more and more of the data being tossed around the net are images and sound files in which it is incredibly easy to hide encrypted messages.
I doubt it is as easy as you say. Truly noisy sources are unusual. You don't have to be 100% sure you have a crypto-terrorist on your hands to search their house, interrogate them, and talk for awhile to everyone they know and then watch them carefully from then on. You don't have to have very many convictions with life sentences to discourage most experimenters which means that you can afford to spend a lot of time and effort on those that you can find. The perpetrator need only mess up once to be put in jail where he belongs. Assuming that it is possible to identify most crypto-anarchist-terrorists as suspects (possibly through informants or surveillance or tax audits) it should be fairly simple to find their contraband disks and data when you search their house. The problem with executables is that they have to execute so you can tell if they are encryption software. How will you handle this problem?
In the absence of strong cryptography, remailers do not offer much anonymity.
Except for the fact that US law stops at the US border (modulo kidnapping Mexican doctors or strongarming the rest of the world to obey US dictates...) Information, on the other hand, is very easy to transport across national boundaries and such transmission is impossible to stop. With remailers outside the US I can send a message to a free nation and have it delivered to whomever I want.
Cross border transmissions of illegally encrypted information is as hard to stop as the use of strong cryptography. If you can stop, for the most part, the use of strong cryptography, then you can stop the use of foreign remailers, errrr, I mean espionage mailers. Were there strong support for it, even cross border activity could be significantly curtailed. This would complicate the practice of carrying stego'd materials across by hand. That may seem improbable, but I know that in the late 1960s the Johnson Administration seriously considered limiting U.S. tourism because of the negative impact it had on the dollar. In the model I am positing, there would be broad popular support for such policies. Peter Hendrickson ph@netcom.com