Interesting write up. I’ve always suspected it was not possible to completely secure any kind of transmissions over the Internet and especially wireless.
In the paper days, you described it pretty well. I went to a military training school to repair optical instruments, where I had to get a Secret clearance just to attend the school. Everything about a periscope is classified...you didn’t carry a book out of the classroom. Nothing in, nothing out. Take notes, they stay there. I didn’t specifically train on periscopes, but did learn how they are built and how they work. All classified. Had to be in the room with one laid out on a bench opened up to see how everything works. Still can’t describe it...to anyone, ever.
And that’s just Secret. I didn’t know about the typewriter ribbons and such, but it makes sense. Anything you type is imprinted on the ribbon.
But being a computer technician for the past 15 years or so, I know how the Internet works. As long as you’re working with wires, it’s semi doable, but once you get into wireless, I don’t see how it can be secured at all. It’s not easy to intercept email over a wire based Internet, but possible. Over wireless, or cell phone, I don’t see how it would be possible to be even remotely secure...
Apparently one has to keep the monitor and csble to same in a good Faraday Cage so it can’t be monitored.
See TEMPEST
FYI, they don't even allow cellphones to go into a SCIF, much less use wireless networks.
WireShark.
It is easy to capture Ethernet traffic on a wired network if you have physical access to it.