>>13999419You'd have to make an argot or a language game based on some existing language it you want it to be easy to memorize, yet hard to decode, like pig latin. However, if you want to make it literally impossible to decode, I don't think there's an easy way; you'd have to artificially create a language from scratch without etymology, which is notably very difficult. Even then, it wouldn't be exactly impossible to decode.
Short answer: theoretically no, but you can get close enough for practical purposes.
