1. learn about the world enough to predict it, like the creepy marketing ais do sometimes. 2. predict some of the message text, maybe from the behavior of somebody who spied on it 3. deduce part of the one-time pad from the message text, easy-peasy 4. one-time pads are made by random processes. so now you've gotta predict the random number generator. this probably means figuring out what shadowy group hacked it. 5. spew out the magic! I'd separate 4 and 1 thru 3 into two separate problems and solve them separately. The groups figuring out that the marketing AIs are controlling people can discover that that implies that any random old AI can hack a computer and influence a random number generation process to solve #4 and radically change our universe. Meanwhile, normal people can use a non-cryptographic random number generator to show the whole system works and frighten people.