Communications During WWII

Information is of utmost importance during wartime. For instance, armies on the front line must be able to receive orders and coordinate with each other. If a country is able to know its enemy’s plans, it would have a significant advantage in the war.

New technologies developed during the 20th century allowed for better and faster ways to communicate. During World War II, all nations employed generally similar methods for military communications. The messenger systems included foot, mounted, motorcycle, automobile, airplane, homing pigeon, and the messenger dog. The telephone and telegraph were widely in use, and wire systems were quite extensive. The developments in radio technology allowed for radiotelephony (transmission of sound/audio by radio) and radiotelegraphy (radio communication by means of Morse Code or other coded signals), though radiotelephony had not yet proved reliable and satisfactory for tactical military communication.

In order to prevent important information from falling into the enemy’s hands, cryptography was a necessity. One well-known example was the Enigma machine. The Enigma machine was an electro-mechanical rotor cipher machine used to encrypt messages. It was invented by the German engineer Arthur Scherbius at the end of World War I was heavily used by Nazi Germany during World War II.

The Enigma machines used a polyalphabetic substitution cipher to encrypt messages. It implemented this through the use of electrical circuitry and a set of rotating disks called rotors arranged adjacently along a spindle. The military Enigma machines used by the Germans had 158,962,555,217,826,360,000 different possible settings, which made it very difficult to crack.

The first complete break into the Enigma cipher was accomplished by Poland in December, 1932. Marian Rejewski, a Polish mathematician and cryptanalyst working at the Polish Cipher Bureau, used the theory of permutations and flaws in the German military message encipherment procedures to break the message keys of the Enigma machine. Poland later shared their decryption techniques and equipment with Britain and France.

The decryption of the Enigma Cipher allowed the Allies to read important parts of the Morse-coded German radio traffic on important networks and was an invaluable source of military intelligence throughout the war. During the war, British cryptologists decrypted a vast number of messages enciphered on Enigma, and intelligence from this source was eventually called Ultra.


Sources:
https://www.britannica.com/technology/military-communication
https://en.wikipedia.org/wiki/Technology_during_World_War_II#Electronics,_communications_and_intelligence
https://www.britannica.com/topic/Enigma-German-code-device
https://en.wikipedia.org/wiki/Enigma_machine
https://en.wikipedia.org/wiki/World_War_II_cryptography
https://upload.wikimedia.org/wikipedia/commons/thumb/3/3c/Muzeum_2_Wojny_Swiatowej_Gdansk_Enigma_cipher_machine.jpg/1024px-Muzeum_2_Wojny_Swiatowej_Gdansk_Enigma_cipher_machine.jpg