History glossary
Shark
the Allied name for a German Atlantic U-boat Enigma key.
- Category
- Codebreaking
- Region
- Europe and the Atlantic
- Date range
- 1932–1945
What it means
The introduction of four-rotor naval Enigma on 1 February 1942 caused a prolonged blackout on this network. Reading resumed in December, with later delays and interruptions.
