Death rays from Mars made pcw@access.digex.net (Peter Wayner) write:

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.

There's a much earlier paper by Frank Rubin in a 1979 Cryptologia which covers encryption+compression with Huffman and arithmetic coding. However the Con-cryption patent covers first compressing, then encrypting. Unless they've got very good lawyers, you can probably ignore it. Peter.