Quote from: cache on April 16, 2012, 07:01 amVery clever!I like this idea a lot, using a book means that you can avoid having to exchange cypher pads and so makes it a lot easier.Thank you Cache,This isn't by any means the only cipher of course but it's the simplest and most powerful one I know - it wouldn't stand up to NSA level analysis but would certainly fool your local cop shop. Even your local police grunt would recognise the significance of a code book of some kind sitting on your book shelf but this way it looks like a collection of harmless books - little do they know! :-)V.