[plug] MS Curriculum at schools and TAFEs ...

[J]

> Actually, I don't think it was ever patented.  Just made a trade
> secret.  Of course, then someone posted it to USENET in 1994...

Applied Cryptography, Second Edition, by Bruce Schneier, p397:

"In September, 1994 someone posted source code to the 
Cypherpunks mailing list - anonymously.  It quickly spread to the 
Usenet newsgroup sci.crypt, and via the Internet to ftp sites around 
the world.  Readers with legal copies of RC4 confirmed 
compaibility.  RSA Data Security, Inc. tried to put the genie back 
into the bottle, claiming that it was still a trade secret even though 
it was public; it was too late."