Colossus computer
Early British cryptanalysis computer / From Wikipedia, the free encyclopedia
Colossus was the world's first programmable electronic digital computer.[1] British code breakers[2] used Colossus for cryptanalysis during World War II.
These messages were sent between the German High Command,[3] and army field commanders. Reading these messages helped the Allies to win the war.
Codebreaker Max Newman worked at the Government Code and Cypher School (GC&CS) at Bletchley Park. His problem was how to get a machine that would help turn German coded radio teleprinter messages into ordinary language. A group of Post Office telephone engineers led by Tommy Flowers worked out how to do this.[4] Their design, which was called "Colossus" used many vacuum tubes (valves). The first machine, Mark 1, worked in December 1943 and solved its first problem in February 1944.[5] Colossus Mark 2 was even better. It first worked on 1 June 1944, just before the Normandy Landings on D-Day. Ten Colossus computers were in use at the end of the war.
British codebreakers called the teleprinter messages "Fish". The messages had been coded by an unknown German machine. They called the machine and its coded messages "Tunny".[6] Colossus imitated the machine and read the coded message from a punched tape. It tried various possibilities of how two of the wheels had been set up. When Colossus found likely settings for two wheels, the codebreaker designed further programs for Colossus until likely settings of other wheels were found. Colossus did not perform all of the decoding process. It just found likely settings of the machine. The output from Colossus was then worked on by people who had a very good knowledge of the German language.
After the war the British codebreakers found out that the code machine was the Lorenz SZ42.[7] All the secret Colossus computers were taken to pieces, so that no one would find out about them. The designs were destroyed. For thirty years no one knew who made them. Between the early 1990s and 2007, a working copy of a Colossus computer was built. This can be seen at The National Museum of Computing at Bletchley Park in England.