M-427 Russian online/offline encryption device reportedly seized in Ukraine

Actually, you had the Chicago Tribune revealing that the US had cracked the Japanese naval code before Midway. Fortunately, the Japanese took this for mere boasting.

Yes, you have a metadata leak. But you can send an urgent request for more … without revealing exactly what you're running out of.

If the idea is to transmit a planned time to initiate an offensive, or some other orders that will not be carried out immediately, then it certainly makes sense.

Right. Block and stream Ciphers themselves can only protect message content. The leak the message length and any peer metadata during the exchange. A perfect cipher produces a message that is indistinguishable from randomness, and can encode all possible messages. This is an intrinsic problem, when we want to hide the cipher texts existence, we usually call that steganography which is a different class of problem. Likewise, hiding the communication graph or message length is more akin to mixnets and anonymity networks/routing.

It’s three classes of problems, of which encryption is the base layer, but we need more constructions to achieve the other layers.

One could hand off the messages to a Morse operator (or what have you) on just about any network, to include some set up after major EMP events, survivors of the events, or some immune to their effects — e.g. print the message out and send it by carrier pigeon or runner, use a heliograph [0], etc. The important thing is that your encryptor still works.

[0] https://en.wikipedia.org/wiki/Heliograph

If it's misinformation, what's the goal? To show that the Russian military is using somewhat dated battlefield comms equipment?