Maybe something that's aided by an AI that generates English texts(a little similar to your iPhone auto-suggest, but more advanced) so that the sentences are va

Maybe something that's aided by an AI that generates English texts(a little similar to your iPhone auto-suggest, but more advanced) so that the sentences are valid and coherent. The recipient would need to know some sort of key/"seed" for the AI, that you'd give them in another channel. I bet something like that would be possible, but the ciphertext would be much larger than the plaintext. Still a fun idea.