Yeah I had wondered about it on and off for years and always kind of assumed that it had been tried and failed or that there was some reason we couldn't do it this way. I'm just hoping it sees some use, time will tell.
Damn, was trying a new dark-mode extension on chat and it fouled up posting messages.
What I was trying to say was: Your protagonist is going to need allies with resources - remember the messages on the Voyager spacecraft? Science would be the basis for communication in a sub-carrier of any conversation. Agreement on the mode of encryption (phonemic/lexical) and keys of a common framework would be the tricky bit that takes time and trust.
