ophcrack: ophcrack (Windows password cracker based on rainbow tables) ophcrack: ophcrack: Ophcrack is a free Windows password cracker based on rainbow tables. ophcrack: It is a very efficient implementation of rainbow tables done by the ophcrack: inventors of the method. It comes with a Graphical User Interface. ophcrack: ophcrack: ophcrack: ophcrack: ophcrack: ophcrack: