>> If I can make convincing messages based on the structure and swapping around pieces of data, then it sounds like I got past the encryption well enough to hav

>> If I can make convincing messages based on the structure and swapping around pieces of data, then it sounds like I got past the encryption well enough to have a partial understanding of the plaintext. I think that no, because you can manipulate the structure of an encrypted string and swap around pieces of it etc, without having to decrypt it. As to making convincing messages, as you say, the entity making the messages and swapping around the data is a language model, but the entity reading the generated messages is a human. It is the human that finds the messages "convincing" as you say. We have no doubts that humans can decode meaning from text, even if we have no idea how we do it, yet. The question is whether language models can do the same thing. And what I say above is that there is no indication that they can, because all they do can be done by language generation, without any decoding of meaning needed.