A mini Enigma-like interactive game for STEM based engagement.

The game has three levels of increasing difficulty to illustrate the basic workings of the Enigma and cryptography.

To simulate the changing of the Enigma settings at midnight, there is a countdown clock. When that expires the settings are changed, and thus the player will need to re-evaluate.

Level 1 makes use of a single "rotor". This is essentially a substitution cypher. There are 5 possible rotors, each having the 26 letters and different "wiring" to scramble the input. The rotor is set to any of the 26 letters as a starting position.

This level is solved by brute force as there are only 5 x 26 (130) combinations. The student must realise that they simply need to methodically work through each rotor and start position.

Level 2 "enhances" the rotor by allowing the lettering to be offset from the wiring. This increases the number of combinations to 5 x 26 x 25 (3380), thus making brute force far less likely. However, application of the offset does not alter positionally throughout the message. It is possible to identify letter repetitions to determine the correct rotor and start position, and then to adjust the letter offset accordingly.

Students could be provided a clue to assist in this determination by being told that all messages end with the same sign-off, for example "WELL DONE". Spotting the pair of L's and E's would enable them to realise that they have the correct rotor settings and simply match up the letter offset.

Level 3 introduces the patchboard. This increases the number of combinations further. The player will need to repeat the deduction for level 2, and also understand the complexities of introducing the patchboard, as it also swap letter pairs. This could lead to an incorrect letter offset that works for some letters only. The player would have to be methodical to work through the letter offset and patchboard settings in the time available.