It can be done, but will tend to be a lot of work.
Doubtful you would be successful using computer programs, as “they” will always have more computer resources than you.
If the comms are that important, expect to devote a team just to send and receive them. This, then, opens up an entirely new line of weakness in your secured comms.
One old technique was using telephone books as keys, there are even better keys now, but along the same idea.
I don’t know if this helps but:
http://en.wikipedia.org/wiki/Kryptos
You might have heard about it. It’s a sculpture at CIA Headquarters at Langley. It was created by a comic book writer. The crypto guys at the CIA have not yet cracked it fully and we’re talking almost 20 years.
Some people have devoted their entire lives to cracking this thing and have not done it. And from what I understand, the guy who created it uses old school stuff. Nothing fancy or modern about it.
I guess the point is, there is a way to encrypt things that cannot be easily cracked. If you could figure a way to apply this sort of method to instant comms you’d have what you’re looking for.
It’s something to think about.
Like you, I was in the Navy. I was one of the snoops you´re concerned about but that was 40 years ago.
The short answer to your question is that, no, there are no ways around newer comms methods, all can be intercepted, not by traditional means, like bugs or traces on a phone or comm line but by a thing called Echelon which catches everything (yes, everthing) sent electronically.
If you want security, think back to when you were passing a handwritten note to Suzy in 3rd grade. Tell her to swallow it after reading it. That´s still secure but that´s about it. You might want to be sure about Suzy!
With the Messiah´s desire to put us all behind his big yoke, your concerns are well founded, IMHO.
Write your message in Navajo. That worked in WWII.
I’m not being entirely facetious. If you know some obscure foreign language, that would slow them down. I recently bought a Basque phrasebook at a used bookstore - it was cheap and I was curious, because it is a language that seems to have no relatives in the world.
Alternatively, make up your own language and share it with your correspondents or at least some key phrases that would be intelligible only to those with whom you’ve shared them.
ESP
I really think the solution you’re looking for is low-tech.
Book code.
Imagine if you will 2 identically arranged bookshelves containing identical books, magazines, periodicals, etc. thousands of miles apart.
A simple substitution code identifies the shelf, book, page, and word.
Yes it’s slow, but remember, security is usually inversely proportional to convenience.
I am no computer expert, but I imagine that even the so-called “encrypted” computer programs aren’t that secure. At least the government will be able to crack them. Unfortunately, the best way is probably “snail-mail.” Maybe not for speed, but in terms of security. We would need to start our own postal service typed thing. The pony express?
If you come up with some kind of secret code that still sounds like an everyday conversation. “how’s the weather?”=
“I have the component.” LOL
I’ll tell you, but then I’d have to kill you.
Odds are, the person with whom you will need to share coded info with is someone you already communicate with on a regular basis. In order to disguise your important messages, you could send unimportant messages or even gibberish on a routine basis. If they have 1,000 messages to sort through in order to find the one, you will gain some time.
That’s not a real solution to your issue, but there is some safety in obscurity.