Changes

As an NSA report explains about World War II:<ref>http://www.nsa.gov/about/_files/cryptologic_heritage/publications/wwii/eavesdropping.pdf</ref>

As an NSA report explains about World War II:<ref>http://www.nsa.gov/about/_files/cryptologic_heritage/publications/wwii/eavesdropping.pdf</ref>

:Two examples of famous ciphers from World War II are the Axis cipher machines, the German Enigma and the Japanese Purple (known to the Japanese as the 97-shiki O-bun In-ji-ki, or Alphabetical Typewriter ’97). Both machines substituted letters for plaintext elements according to daily settings (key)

:Two examples of famous ciphers from World War II are the Axis cipher machines, the German Enigma and the Japanese Purple (known to the Japanese as the 97-shiki O-bun In-ji-ki, or Alphabetical Typewriter ’97). Both machines substituted letters for plaintext elements according to daily settings (key) for each machine. Interestingly, most ciphers used by all sides during the war overwhelmingly were manual in nature. That is, they involved the use of paper

for each machine. Interestingly, most ciphers used by all sides during the war

overwhelmingly were manual in nature. That is, they involved the use of paper

charts and key. Such a manual cipher was the double transposition cipher used by

charts and key. Such a manual cipher was the double transposition cipher used by

German Police units to encrypt their reports about the massacres of Jews, partisans, prisoners, and Soviet commissars to Police headquarters in Berlin.

German Police units to encrypt their reports about the massacres of Jews, partisans, prisoners, and Soviet commissars to Police headquarters in Berlin.

 

The Enigma was a portable cipher machine, roughly the size of a typewriter, which could encrypt and decrypt secret messages.  It used electro-mechanical rotors to convert a message to a secret code, and then another machine could decode that same message and reveal the original message.  This machine was commercially available beginning in the early 1920s.  The Nazi German military version generated codes widely thought to be unbreakable.  

The Enigma was a portable cipher machine, roughly the size of a typewriter, which could encrypt and decrypt secret messages.  It used electro-mechanical rotors to convert a message to a secret code, and then another machine could decode that same message and reveal the original message.  This machine was commercially available beginning in the early 1920s.  The Nazi German military version generated codes widely thought to be unbreakable.