During World War II Nazi Germany primarily encoded its messages through the use of what was known as the "Enigma" machine. Enigma’s use by the Wehrmacht stretched back to the early 1930s and originated from a design created by Hugo Alexander Koch in the Netherlands.
Although heavily modified prior to the Second World War’s onset, the Enigma machines used in 1939-1945 remained similar to Koch’s prototypes from two decades prior. For a variety of reasons the Enigma machine was extraordinarily difficult to crack.
The Battle of Britain remains today one of the more heavily focused upon events of the Second World War. In particular, events that occured in English skies from August of 1940 through early 1941 attract the lion's share of attention.
What must be remembered however, is that the horror of facing random death, injury, or loss of possessions facing the average British citizen continued throughout World War II. During the spring of 1942 German night bombing raids managed to terrorize a significant number of people.