The battle of Medenine, March 6th 1943, was influenced by ENIGMA.
Before this battle started, the situations was as follows:
- In Souh-East of Tunisia, Montgomery was pushing hard but slowly
- In the West, Rommel had used the time to defeat American forces
- Rommel had to group again his forces to stop Montgomery
Now, why had the Germans the use of radio communications? Because phone communications were not that much developed in Tunisia, and French had sabotaged some.
=> So they used radios and Enigma helped decoding the message
Enigma helped knowing the place of the offensive because Rommel had to tell to dispersed armored units where to meet. This was probably as well a lack of cautiousness from German radio operators.
So Montgomery concentrated antitank guns, minefields and tank reserves and defeat the Germans suffered 50 tank as well as infantry losses.
Without Enigma, the German defeat would have not been that big and losses not that high. Moreover, British tanks would have suffered losses as well and that would have hampered later offensive.