Battle: World War II
The British worked tirelessly to break Germany's codes during WWII, especially those produced by the Enigma machine, which was capable of creating as astonishing 150,000,000,000,000,000,000 codes.
Intercepting codes and attempting to find consistency, 10,000 people worked using different computers, including the "bombe," which eventually broke the code using 500 electrical relays and 11 miles of wiring to test trillions of combinations.
Efforts to crack the Engima's complex codes, led by British scientist Alan Turing, were famously the subject of the award-winning 2014 film "The Imitation Game."
Fittingly, one of the original Enigma machines is on display at Washington, D.C.'s Spy Museum.