Median writes:

I may be in trouble for not knowing basic literature, but if so so be it. Would a code you created yourself be secure? If you create your own language from scratch, and the 'enemy' never gets something to act as Rosetta Stone, is it still not secure? Or is the "aliens figure out our language with lots of computers" cliche bogus?

I want to avoid casually dismissing Median's question without writing a mini-essay on code-breaking. Especially when so many fine and accessible (easy to read) books on code-breaking are available. (To find them, cruise your local library. I recall the Herbert S. Zim book as being a very fine introduction. Basic, and nonmathematical. But a good start. I read it in junior high school, many years ago. I was reminded of it recently, when I think Whit Diffie cited it as an influence on him as well--he obviously was more influenced by it than I was, as he went into crypto and I went into physics, a much less interesting field.) Basically, word-frequency analysis kill simple codes. Replace the word "the" with the string "globflq" and it's still going to be fairly obvious that "globflq" means "the." And so on. And, as Median mentioned, a few words may become known, in all the usual ways, and thus a Rosetta Stone has been found. The issue of communication with extraterrrestrials--some day perhaps--is an interesting one. I have no idea what work has been done on "breaking the code" when almost no clues exist. Some SF writers have explored this idea. But in summary, codes are a poor approach. The entropy of coded messages gives clues about the underlying plaintext and eventually the code falls. Usually fairly quickly. Ciphers (or cyphers) are superior, as the entropy of the ciphertext can be very high (roughly, "maximally random," though I don't want to get into what randomness means here). Kahn's "The Codebreakers" remains the definitive book. All Cypherpunks should at least read the paperback abridgment of the original massive book. "Kahn on Codes" is also pretty good. --Tim May -- .......................................................................... Timothy C. May | Crypto Anarchy: encryption, digital money, tcmay@netcom.com | anonymous networks, digital pseudonyms, zero 408-688-5409 | knowledge, reputations, information markets, W.A.S.T.E.: Aptos, CA | black markets, collapse of governments. Higher Power: 2^756839 | Public Key: PGP and MailSafe available. Note: I put time and money into writing this posting. I hope you enjoy it.