[bwarp]

Yes. You need to look up "Electronic Countermeasures". There are plenty of chunks of real info out there on it. Pretty much any form of it is plainly described despite the usual expectation that it's top secret or classified. There are handy forms of point to point encryption which can be easily used on paper and via voice as well. Nice read here on it: http://users.telenet.be/d.rijmenants/en/onetimepad.htm

Also, remember the general rule is that if the broadcaster can become a target, so can the oppressor.

When I finished my EE qual, I actually ended up working as an engineer for one of the more nefarious defense contractors. After about 2 years, I realised that what I was working on was engineering devices to watch people, to keep secrets and kill people. So I gave them the finger. My morals have kept me thinking about this for the last 20 years.

[pnathan]

I came to the conclusion some time ago that I would not work to build devices to harm or spy upon people until it became a matter of doing so or being irresponsible to my family.

Rather work at a Taco Bell than write a censorship program.

[Tichy]

A onetime pad would be a good example of something I would not like to have on me if got grabbed by some oppressive regime. That is the kind of problem I mean.

Tor is not a solution, because it could be found on your computer.

Radiowaves - I don't know, I would also expect them to be easily detectable, but I'll look it up.

[bwarp]

A one time pad can be easily hidden amongst other text i.e. a book printing with some rules applied (third letter of every alternate sentence).