North Korea beamed numbers transmissions to the South with three different stations. Two of them operated via Radio Pyongyang and were last heard on August 25th & December 8th 2000. A third station operated on 4770 and 5870 and was last heard on September 11th. Numbers transmissions from North Korea continue in Morse Code.
It makes one wonder if these numbers transmissions were actually used for agents or simply "misinformation" broadcasts filled with random numbers. It stretches believability to think that North Korea pulled all its agents from the south. Yet Morse numbers continue. This is just speculation on my part, but it would appear that the three numbers stations that ceased transmitting may have been transmitting dummy messages in the first place, either in order to make South Korea believe that more agents were operating there then there actually were or to try to overwhelm cryptanalysis efforts.
Lest anyone think that North Korea has had a change of heart toward capitalist societies, the website of the KCNA, or Korean Central News Agency, contains a lot of old cold war communist propaganda. Check out http://www.kcna.co.jp to find out what we "imperialist" Americans are up to. Some of it is even laughable. North Korea used to broadcast the same material in RTTY 50/175 from station HMF, but I'm not sure if it's still active.
Al Fansome passes along an article from the NY Times dated Feb. 20. The article details a claim from a Harvard computer science professor, Dr. Michael Rabin, who says he has discovered a way to send coded messages that are totally unbreakable, even by an all-powerful entity with unlimited computing power. If he is correct, then he has discovered the first code that is totally unbreakable. One-time pads, even though they are highly secure, can still be broken with powerful supercomputers. Even systems such as PGP, while difficult, can be eventually broken.
Rabin's code is based on a key that vanishes as it is used. While not the first to develop this idea (the German Enigma machine used this method), Rabin claims that never before has anyone been able to make it both workable and to prove mathematically that the code cannot be broken.
Systems like PGP can be broken because users use the same key for encoding & decoding many times over. Rabin's system uses a stream of random numbers to encode & decode the message. The number stream is not stored in the computer's memory, and essentially vanish as the message is encrypted & decrypted. A PGP key may be stolen, but there is no chance of stealing the key for Rabin's code.
Mathematicians and computer scientists say that Dr. Rabin may have solved the ultimate problem in cryptography, finding a practical code that is totally unbreakable. However, they also claim that making a totally unbreakable code may not make much difference in today's world. Some claim that today's codes are already so good that there is little advantage to making codes totally unbreakable.
At this time, Dr. Rabin's idea is just an idea backed up by mathematical proof that it works. He says he has no interest in profiting from it, and no company is offering to buy it.
Many thanks to this month's contributors. Keep that information coming, folks. This is your column.