Editing Encryption (section)

=== 19th–20th century ===
Around 1790, [[Thomas Jefferson]] theorized a cipher to encode and decode messages to provide a more secure way of military correspondence. The cipher, known today as the Wheel Cipher or the [[Jefferson disk|Jefferson Disk]], although never actually built, was theorized as a spool that could jumble an English message up to 36 characters. The message could be decrypted by plugging in the jumbled message to a receiver with an identical cipher.'''<ref>{{Cite web|url=https://www.monticello.org/site/research-and-collections/wheel-cipher|title=Wheel Cipher|website=www.monticello.org|language=en|access-date=2020-04-02}}</ref>'''

A similar device to the Jefferson Disk, the [[M-94]], was developed in 1917 independently by US Army Major Joseph Mauborne. This device was used in U.S. military communications until 1942.<ref>{{Cite web|url=https://www.cryptomuseum.com/crypto/usa/m94/index.htm|title=M-94|website=www.cryptomuseum.com|access-date=2020-04-02}}</ref>

In World War II, the Axis powers used a more advanced version of the M-94 called the [[Enigma machine|Enigma Machine]]. The Enigma Machine was more complex because unlike the Jefferson Wheel and the M-94, each day the jumble of letters switched to a completely new combination. Each day's combination was only known by the Axis, so many thought the only way to break the code would be to try over 17,000 combinations within 24 hours.<ref>{{cite news |last1=Hern |first1=Alex |title=How did the Enigma machine work? |url=https://www.theguardian.com/technology/2014/nov/14/how-did-enigma-machine-work-imitation-game |work=The Guardian |date=14 November 2014 }}</ref> The Allies used computing power to severely limit the number of reasonable combinations they needed to check every day, leading to the breaking of the Enigma Machine.