If you want secure communications, use simplex radio. Encrypt it and change channels hourly. Yes the entire band can be recorded as well. But they have to be in proximity of the signal.
We already have secure Communications in the military. They use spread spectrum multiband technology. Good luck to decoding that unless you have the key. But therein lies the rub. Technology used to get the key Although our military communications remain secure to some extent. But even though they are using secure communications when orders are sent they have a cipher key that must match on both sides. If it doesn't it is assumed to be fake. That's different than real time dispatch.
I don't know how you can say to use simplex and encrypt it and change channels hourly. If the key is compromised so are your simplex.
Do you remember the mass killings and roving terrorists in San Bernardino California? The man had an iPhone and Apple refused to provide assistance decrypting the phone. They said it was impossible and would destroy the content. Our anti-terrorist folks paid a man $1,000,000 and almost instantly he decrypted the key.
I'll bet if we came up with a million dollars he would decrypt AES256 and provide the software that would allow us to intercept it OTR and grab the key.
As the owner of a hosting company that uses his own Hardware that includes firewalls and switches I can tell you that my own network is not secure. If somebody wants in there going to get in. I am not deluded in thinking because I know that if Yahoo can be broken into, so can I. If Citibank can be broken into, so can I. But why break in? Some do it just to prove that they can do it while others do it so that they may harness to computing power of thousands or hundreds of thousands of computers at any given time. This is how complex keys are easily hacked.
When you think of it this way understand that the computers on the Space Shuttle are 8088 processors. The Originals going all the way back to the IBM or the Tandy that first hit the market. One computer performs one function only on the Space Shuttle. Even though today's computing power can fit into a watch, they don't trust it to one computer.
I will end with this. 5G processing. As mobile devices and smartphones continue to advance so does their speed. I use my cell phone more than I use my desktop now.
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