A good question. An analog from simpler times:
More years ago than I care to count on my fingers I was a cryptanalyst in...let's say, near, the Mideast. The traffic we were intercepting and working on was in Russian, Italian or one of several dialects of Arabic, none of which I speak, or more to the point, read. But when you are applying decryption techniques you don't necessarily have to know what exactly what the message says to make progress, just what the plaintext should LOOK like.