alt Hacker NewsToo many narcs on the ham bands would track you down for operating encrypted ham packet radio. You're better off using something like LoRa over the ISM bands. Build out a network of hidden mesh nodes over the area you'd like to operate and that's probably the closest you'll get to a true clandestine network. Of course the major issue with transmitting any RF energy is that someone can watch the spectrum and look for those transmissions and eventually track down your nodes. LoRa uses DSSS which if operating at minimum power, could help hide transmissions.
If you want to add some illegality to the system, you could piggyback on amsats or open relay satellites like FLTSATCOM to expand your network and hide better.
Actually LoRa uses chirps designed for iiuc partially analog demodulation to be very energy-efficient.
For hiding you'd be able to use actual DSSS with e.g. AES encrypting a suitably fine grained clock piggybacking on GPS as a time reference, keyed by a shared secret. Then just hone in with e.g. a Costas loop like a GPS receiver does to it's satellites (where the sequence is sourced from a simple clocked logic circuit that's cheap and offers better than random spreading gain at the cost of being cryptographically useless) and demodulate the payload the same way.
You could start off at GPS synchronous sequence generator timing, and slowly shift it at increasing delay until lock in is archived or an implausibly long implied travel distance (signal loss!) is reached (then you can give up and start over, go to sleep and try later, etc.).