A cipher machine is a device used for encoding and decoding individual words and messages. The evolution of the cipher machine has been heavily influenced by seemingly inevitable instances of code cracking. Historically used by militaries and governments worldwide, cipher machines have evolved from their simplistic wooden wheel construction to high-tech computers outfitted with router encryption software.
The earliest documented case of the use of ciphers details Julius Caesar, who used ciphers as a means of communicating with his generals on the battlefield. His cipher utilized a shift in alphabetic characters that remained constant throughout the entire message, known as a monoalphabetic cipher. Caesar's cipher algorithm would later serve as the inspiration for a cipher machine which would be the first to mechanically encrypt messages.
Leon Battista Alberti, known as the father of western cryptography, developed the first mechanical encryption machine. Inspired by Caesar's ciphering techniques, Alberti's machine was the first to use a polyalphabetic cipher. Developed in 1467, the Alberti Cipher utilized more than one alphabet, and switched between alphabets during the encipherment of the message with the aid of a metal cipher disc.
The Vigenere Cipher emerged in 1533 as described in a work by Giovan Battista Bellaso called La Cifra. The encryption method used a series of Caesar ciphers that were based on a single key word, in essence, a polyalphabetic substitution method. Due to a misattribution of credit during the 19th century, the ciphering method was credited to Blaise de Vigenere and has been known as the Vigenere Cipher ever since.
The Jefferson Cipher Wheel, invented by Thomas Jefferson, was developed in 1795 and employed a stack of 26 wood wheels mounted on an axle. Each wheel was distinct, with the alphabet arbitrarily arranged over its circumference. The Jefferson Cipher Wheel proved a strong instrument for small, short messages and was used by the United States military until 1942.
One of the most famous cipher machines, the Enigma machine, was invented by a German engineer named Arthur Scherbius in 1918. After a stint of unsuccessful marketing on Scherbius' part, the Enigma was purchased by the German government in 1926. The Enigma's code was successfully broken by US, British, and Polish cryptographers; however, the code fracture was not publicly acknowledged until 1974.
The US Army's M-209 Cipher machine was developed by a Swedish businessman and cryptographer named Boris Hagelin. The cipher machine employed a series of rotors, or discs, joined with a pin-lug system that permitted the multiple encipherment of each character of a message. Used extensively throughout the Second World War, its code was broken by the Germans in 1943. The M-209's use became limited to strategic battlefield communication only and remained in use during the Korean War.
Modern cipher machines employ the effectiveness of computing to ensure intelligible cryptology and security. Cipher machines now offer added conveniences that have historically been just beyond reach. The encoding and decoding of messages no longer requires the presence of human personnel. Additionally, messages are now guaranteed integrity, and sender authentication is standard, offering a level of confidentiality previously unavailable.