Why is it that the idea of taking a difficult problem, such as a knapsack problem, and using it to encode ciphers, was abandoned? Too many trapdoors? These NP-complete type problems seem ideal since they can be verified in polynomial time, but are practically impossible to solve for any significant input. Verification of a solution could be decryption, where the solution is the key, and the problem could be used to encode the text somehow. I understand that Shamir broke the knapsack problem. So, is that enough reason to completely abandon this approach? Nobody seems to talk about it anymore. Wonderer (My apologies to those who prefer to use this list to play games with pseudonyms and discuss their paranoid ideas. I prefer to use cypherpunks to learn about cryptography and its interesting applications) ------------------------------------------------------------------------- To find out more about the anon service, send mail to help@anon.penet.fi. Due to the double-blind, any mail replies to this message will be anonymized, and an anonymous id will be allocated automatically. You have been warned. Please report any problems, inappropriate use etc. to admin@anon.penet.fi.