Stories in Information Security #2 _ World War Two

Enigma

As long as people had invented characters, people have found the importance to protect the information the want to transmit, especially during the war time. All the empires wanted to protect the information. For Caesar, he invented the cipher method to protect what his strategy. For Sparta, they write the text on a stripe of sheepskin which circle on a wooden stick, then move the stick to protect the information. All these method are processed by human beings so that there will always be some artificial mistakes. Before the ending of World War One, Arthur Scherbius who was a electronic engineer from Germany. He invented a mechanical cipher machine in the year of 1918. He was so proud of this machine and named it Enigma. From that time, human began to encrypt information through machine. This was a significant improvement in the history of information security. During World War Two, German deployed 30 thousands Enigma for army. Although Enigma was a significant improvement, it still used the substitution cipher method which was almost the same method with Caesar Cipher. However, since Enigma was a cipher machine, it can list much more cipher solution than human can list. Based on the principle of Enigma, it can provide 10 to 114 square possibilities. Even after the Alliance captured several Enigma and learned the principle of it, the Alliance still face 10 to 23 square (76 bits) possibilities to solve a cipher-text, which means it was almost impossible for Alliance to solve cipher-text by enumeration method. In the end, Enigma was be cracked by Alliance because the mistake made by German operator and the capture of Enigma. Scientist believed that the crack of Enigma Machine helped Alliance won the WW2 2 years advanced. After the World War Two, with the development of computer, human began to try the more sophisticated method to protect information.