Basic Classic Symmetric Breakers Advanced
Breaking a Simplified Enigma Machine
The real wartime Enigma resisted brute force because of two unknowns stacked on top of its rotor positions: which three rotors were chosen and in what order, and how the plugboard was wired. Together these push the key space past 10^20. Strip those two unknowns away and only 17,576 rotor positions are left, small enough for a modern computer to brute-force outright.