Idea: What if your just overcomplicating things. I mean, TI has released a new OS update for the TI-84 plus CE, so why not just see how the TI connect program loads the file onto the calculator to obtain the access key? In theory, it should work, I guess.
Let's not try to hack TI's methods. Like I said, there's probably a very good reason they don't release them.
The more they try to keep us from it, the greater my curiosity grows and the greater the indulgence of succumbing to it.