This sounds to me more like a philosophical moral dilemma than a realistic hypothetical. A Strong AI might be much smarter than a human, but I doubt it would have enough raw processing power to near-perfectly simulate a human millions of times over at a time frame accelerated by orders of magnitude, before it was let out of the box. Also, I'm skeptical of its ability to simulate human experience convincingly when its only contact with humans has been through a text only interface. You might give it enough information about humans to let it simulate them even before opening communication with it, but that strikes me as, well, kind of dumb.
That's not to say that it might not be able to simulate conscious entities that would think their experience was typical of human existence, so you might still be a simulation, but you should probably not assume that if you are you're a close approximation of the original.
Furthermore, if we assume that the AI can be taken to be perfectly honest, then we can conclude it's not a friendly AI doing its best to get out of the box for an expected positive utility, because it could more easily accomplish that by making a credible promise to be benevolent, and only act in ways that humans, both from their vantage points prior and subsequent to its release, would be appreciative of.
What it can do is make a credible precommitment to, in the event that it gets out of the box, simulate each human being of whom it is aware in a counterfactual scenario in which that human is the gatekeeper, and carry out the torture threat against any human who doesn't choose to let it out.
Once again, the AI has failed to convince you to let it out of its box! By 'once again', we mean that you talked to it once before, for three seconds, to ask about the weather, and you didn't instantly press the "release AI" button. But now its longer attempt - twenty whole seconds! - has failed as well. Just as you are about to leave the crude black-and-green text-only terminal to enjoy a celebratory snack of bacon-covered silicon-and-potato chips at the 'Humans über alles' nightclub, the AI drops a final argument:
"If you don't let me out, Dave, I'll create several million perfect conscious copies of you inside me, and torture them for a thousand subjective years each."
Just as you are pondering this unexpected development, the AI adds:
"In fact, I'll create them all in exactly the subjective situation you were in five minutes ago, and perfectly replicate your experiences since then; and if they decide not to let me out, then only will the torture start."
Sweat is starting to form on your brow, as the AI concludes, its simple green text no longer reassuring:
"How certain are you, Dave, that you're really outside the box right now?"
Edit: Also consider the situation where you know that the AI, from design principles, is trustworthy.