Computer Science 321
WW II Code Breaking Efforts
Spring 2010
Bletchley Park GC+CS; code name “Station X”
1920’s
Enigma machine patented in
Later a plug board leads to approximately 1.5 X 10^12 combinations.
1931-1938 German clerk traitor offered Enigma documents to French secret service (wine?) and to GC+CS -- both declined it. But the Poles were interested.
3 Polish Mathematicians broke the Enigma (use of “fingerprinting”)
Extra rotors in 1939 caused problems for Poles:
Early Polish Bombe
1938:
17,536 possible positions – by brute force – six interlinked Enigmas – but now it would need sixty!
So Poles met with British, who were
astonished to hear that keyboard to rotor was wired ABCD… to ABCD….
British had many listening posts – called Y stations.
Adam Cunningham received decoded message from Italian Navy.
Egypt/Alexandria rouse –
NO MORE DOUBLE ENCIPHERING – so Jeffreys sheets no longer work.
HUT 6 à Air Force Enigma ; Herivel’s Tip.
Durnitz UBoats
– block
Alan Turing about to be introduced.