I haven't read the supposed Concryption patent so I don't know what the claim structure is. But if they truly claim the right to do encryption and compression simultaneously, then I've got some prior art that should knock out such a broad claim. The paper is "A Redundancy Reducing Cipher" (Cryptologia, May 88). It's not very secure, but it does do some manner of encryption at the same time as compressing a file with a Huffman-like system. The journal is found in many university libraries so it should be easy to produce a solid counterclaim. If anyone has the plaintext to the Concryption patent (5479512), I would like to read it. -Peter