MilanApril 9, 2008 3:57 PM  Simon Singh's "The Code Book" has a
detailed description of the history and mathematics involved in
breaking Enigma.  It is one of the best books on a technical
subject I have ever read.  mooApril 9, 2008 3:58 PM  An
interesting read. I couldn't help but think of Cryptonomicon
while reading it. Most people don't realize that without the
contributions of those clever mathematicians and cryptanalysts,
the Allies might not have won the war.  Carlo GrazianiApril 9,
2008 4:30 PM  The curious thing is, after February 1942, Doenitz
had what essentially amounted to positive confirmation that the
Allies had been reading the three-rotor Naval enigma, since the
decline in sinkings that had begun in the Spring of 1941 was
suddenly reversed with the introduction of the fourth rotor. He
must have felt that his suspicions had been justified by the
evidence, at that point.  Nonetheless, when the war turned
against the U-Boats again in the Spring of 1943, there is no
evidence that I'm aware of that