Dr. James Grime explains how the Enigma machine's flaw, where a letter can never become itself, was used to break the code. He demonstrates how the British code breakers, including Alan Turing, used a process of elimination to figure out the plug board settings. The Bombe machine, built by Turing and Gordon Welchman, was used to speed up the process by applying electrical currents to check multiple possibilities simultaneously.
The machine worked by eliminating incorrect possibilities, and the correct setting was determined by what was left. The process was repeated for each rotor position, taking around 20 minutes to complete.
Grime also discusses how the Enigma machine's makers could have avoided the flaw by allowing a letter to sometimes become itself, as was done in the British Typex machine. The Germans reportedly tried to break the Typex code but gave up, concluding it was more secure than the Enigma machine.
The video concludes with a recommendation to watch additional videos on the Enigma machine and an invitation to explore other content, including a chemistry channel featuring high-speed camera footage of reactions in ultra slow motion.
Here are the key facts extracted from the text:
1. The Enigma machine was a coding device used by the Germans during World War II.
2. The machine had a flaw in that a letter could never become itself when encoded.
3. This flaw was used by British code breaker Alan Turing to help break the Enigma code.
4. Turing built a machine called the Bombe machine to help break the code.
5. The Bombe machine was an electrical device that used the flaw in the Enigma machine to help decipher the code.
6. The machine used a process of elimination to narrow down the possible settings of the Enigma machine.
7. The British also built a machine called the Typex machine, which was a version of the Enigma machine without the flaw.
8. The Germans tried to break the Typex code but gave up, concluding that it was more secure than the Enigma machine.
9. The Bombe machine was named in honor of a Polish code-breaking machine called Bomba.
10. The Polish machine, Bomba, was a smaller machine that exploited a flaw in German procedures to break Enigma codes.
11. The Germans changed their procedures, making it harder for the Polish machine to break the code.
12. The British machine, Bombe, was designed to be more robust and able to break the code even if the Germans changed their procedures.
13. The Bombe machine could break the code in under 20 minutes.
14. The machine was used to break army, air force, and naval Enigma codes.
15. The naval Enigma codes were more difficult to break because the rotor starting positions were sent at the beginning of each message in a different code.
16. The British were able to break the naval code by working out how the rotor starting positions were encoded.
17. The German Enigma machines changed their settings every morning at midnight.
18. The British had to break the code every morning to keep up with the changing settings.
19. The Bombe machine was a crucial tool in breaking the Enigma code and helping the Allies win the war.