Cracking bank PINs by playing a Mastermind Game
Flaminia Luccio

In this talk we discuss the relation between the problem of cracking (i.e., correctly guessing) bank PINs for accessing Automated Teller Machines (ATMs) and the problem of solving the Generalized Mastermind Game (GMG). The GMG with N colors and k pegs is an extension of the Mastermind game, played with 6 colors and 4 pegs. In both games, one player has to conceal a sequence of k colored pegs behind a screen and another player has to guess the exact position and colors of the pegs using the minimal number of moves.

We show that a general game, called the /Extended Mastermind Game/ (/EMG/) includes both the GMG and the PIN cracking Problem, and we present strategies to crack PINs based on an extension of a classical technique used to solve the Mastermind Problem.