GCHQ Releases Never-Before-Seen Images of Colossus, the World's First Digital Computer

Marking its 80th anniversary, the intelligence agency sheds light on the secret WWII code-breaking machine that remained classified for decades.

GCHQ, the UK’s intelligence agency, has released never-before-seen images and documents related to Colossus, the world's first digital computer, on its 80th anniversary.
Colossus was developed by British scientists between 1943 and 1945, and played a crucial role in breaking the Lorenz cipher, a code used for communications between high-ranking German officials in occupied Europe during World War II.
Despite its historical significance, Colossus remained a highly classified state secret for decades. Its existence was revealed in 1975, but it was not until the early 2000s that substantial information about the project was released to the public.
Eight out of the ten Colossus machines were destroyed after the war to prevent the technology from falling into the hands of the Soviet Union. The remaining two were later destroyed in the 1960s.
A fully working reconstruction of a Colossus computer can be seen at the National Museum of Computing at Bletchley Park.