Though, surely secure steganography with LLMs should be quite easy? Presumably there are things like key exchanges that look like randomness, and then you coul

Though, surely secure steganography with LLMs should be quite easy? Presumably there are things like key exchanges that look like randomness, and then you could choose LLM output using that randomness in such a way that you can send messages that look like an LLM conversation? Someone starts the conversation with a real message 'Hello!' and then you do some kind of key exchange where what is exchanged is hard to distinguish from randomness, and use those keys to select the probabilities of the coming tokens from the LLM. Then once they is established you use some kind of cipher to generate random-looking ciphertext and use that as the randomness used to select words in the final bit? Surely that would work? If there is guaranteed insecurity, it's for things like watermarking, not for steganography?