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Enigma's Rotor System
The original Enigma rotor system was invented in 1915 by two Dutch naval officers, R.P.C. Sprengler and Theo A van Hendel. -
Albert Scherbius-Enigma
The actual Enigma machine was invented by Albert Scherbius, who actually tried to have the German military take the idea. However, a German company called Gewekschaft Securitas bought his patents instead. -
German Navy Buys Enigmas
During 1925, the German Navy started buying Enigma machines and modified it to accommodate their needs. -
German Army Buys Enigmas
During 1925, the German Navy started buying Enigma machines and modified it to accommodate their needs. The German Army followed this action in 1928 -
Zygalski's Sheets Invented
The last major method of decryption was Zygalski’s Sheets. This method used a set of 26 perforated sheets for each of the six possible sequences. Marian Rejewski explained this method. In simplified terms, he states that the sheets are overlapped and moved in the proper sequence until the visible openings decreased enough to the point that a single opening remained, resulting in the solution. From this, the code-breakers could calculate the order of the rotors, the setting of the rings, etc. -
Rejewski Invents Cyclometer
Marian’s Cyclometer included two drums, a set of 26 bulbs and switches (for each letter), and cards to record matches. The specific date of this invention is unknown; the year was most likely 1934 or 1935. -
German AF Buys Enigmas
During 1925, the German Navy started buying Enigma machines and modified it to accommodate their needs. The German Army followed this action in 1928, as well as the German Air Force in 1935. -
Poland Designs Bomba
Poland (specifically Marian Rejewski) designed a machine that aided in the efforts to break Enigma. This machine was based on the principle that the message key is sent twice at the beginning of each message and that a particular plaintext letter, might yield the same ciphertext 3 positions apart (e.g. AWB, TWY). Such coincidences were called Females. -
World War II Starts
World War II started on this date. The main enemy was Germany (Nazis). -
World War II Ends
World War II Ends on this day. In the end, the Allies won, which included Britain, France, the United States, etc.
