Some encryption is next to impossible to decode.
Yes, I bet he wished he had used it!!
I used to see the Soviet transmissions gathered at LRR sites in Alaska.
All Top Secret, but nothing that would compromise themselves. Seemed alot of it was to test our abilities. Those Ratheon guys that work the radar used to laugh at the stuff they would get.
But still, NOTHING transmitted is 100% safe, ever.
I have seen the capabilities we have, and there is no reason to think our enemies are less capable at it than we are.
It was cool. The Ratheon techs' would wait at the airstrip with their data in a briefcase chained to their wrist every week. The plane would land and no matter who was on it they had to wait while the courier de-planed. He would meet the tech, like 100 yards from every one else (who could not approach them). They would do their secret handshake and passwords and the courier would accept that case and pass off his with new code info.
When the all clear was given then other passengers would unload or board, then the courier would get back on and leave.
All this on dirt strips in interior Alaska or on the coast in absolute God Forsaken locations. Twin piper planes.
I could tell you a lot more, but I did need clearance for all those jobs. If it can't be Googled, I figure I can't say it!