Computing and magic have a lot in common. They both involve algorithms. ‘Mentalism’ tricks also use the same ideas as in cybersecurity. Here is a mentalism trick.
You ask four volunteers to help in an experiment in mind reading. You give them a list of 15 numbers and ask them to jointly pick one without telling you what it is. You then give each a card which contains a jumble of numbers and letters. They stand in a line facing you, cards hidden from your sight. They each look to see if the jointly chosen number is on the card. If it is then they must close their eyes and think hard only of that number. Those holding a card without the number choose one of the letters on their card instead, and stare at it, thinking only of that letter. That way they won’t confuse you, you say.
You close your eyes, think hard and then pick up the thoughts about the secret number and announce what their secret number was!