The problem with a consistent language, although perhaps very obscure, is that it's symbology is consistent and a pattern will eventually reveal itself, with scrutiny. A letter or number is assigned a sound or meaning. You have to dissociate this consistent connection between certain values and their equivalent interpretation,.into a language/code someone else can't understand. The associations must, therefore, necessarily be randomly generated with each message, so a key has to be produced just for that message. I think that's how encryption works.