You forget. You first have to get the cipher to the other side first.
No shit Sherlock. But what have you forgotten.. Gee let me see. Oh yes, that's right I said I have friends who travel to Russia and I'd like to be able to talk to them freely while they're there, remember?
First Contact Problem.
Which was solved the moment we met in that bar. Remember?
Aside from that, when things were locked up tighter than North Korea this didn't stop things. Agents still found people in government areas they could bribe or otherwise convince to pass secrets. These people were facing imprisonment in the worst places on earth and then death, often for their whole family as well, and yet the US and other countries has quite a few "assets". Without internet, with very few phone lines, little radio range, no personal transmitters, what they did have heavily monitored, with all that they still sent and received information. And in a way that most of the time was undetected.
In the case you were asked about (remember?), we're talking chat between a couple of people who meet often, spend whole days together "normal" things.
And the Russians are infamous for their intelligence network, remember?
Yeah, pretty hard to get stuff in and out of Russia since they're neither allowed to travel to other countries nor even communicate or receive data from outside sources. Oh no, wait a minute, that's changed now. Remember?
Unless you can demonstrate a zero-knowledge cipher.
Could I use one of your posts as an example?
Plus, if the Russians control most of the lines in there, don't you think they'd be able to do some kind of on-the-fly sanitation and mangling to throw things off, just on general principles?
To what purpose? Changing the data in all emails so the words no longer say the same? Random flipping bits in pictures to possible throw off something in that? There's lots of bits to flip, and if I send a dozen pictures with a dozen possible ways to flip them, only one has to get through intact. What if I build a Linux distribution and make use of signed code among the updates, and put a few new random background images in as part of that - how will this remain undetected? The checksum will be out, so we know something has changed in the downloads. This would only work in your mind.
What's sauce for the goose is sauce for the gander (meaning, what if the Russians are doing the same thing as a COUNTER-intelligence ploy).
They're not. We use tools like Freefilesync, and of course some of the various cloud offerings do the same - flipping a bit in a picture should cause a different checksum, flipping several will. Yet thus far what has come over in email and what is in his local backups match exactly, so no flippage there. In a 4MP camera there's plenty room enough to embed several code layers.
If the Chinese could do it, why not the Russians? At the very least, they could slow clandestine communications to a crawl.
Again, a country with fairly free borders, and still a lot of traffic. A plain text cipher passes all borders without notice unless for some reason you're really being targeted and all your communications stopped. Chinese can still upload to picture sites that can be accessed from outside China, same for the Russians.
Remember that much in the way of "clandestine communications" are very short messages comprising of a very few words (or dates/numbers etc), or sometimes a common phrase that can be sent safely in the clear, eg "Jim's latest poem". Hell, codes have been transmitted in things like recipes. Personal ads in newspapers have been a huge favourite for a long time. Many blogs say far more than the words that appear on the page.
There was no argument to counter in your post, I'd already covered them in previous posts.
Perhaps in your next post you can mention some of these "specifics" you claim to have?