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.
Thanks. But large encrypted messages on monuments doesn’t work for immediate comms. But I get your gist.