A History of US Communications Intelligence During WWII

The revelations about World War II cryptology - begun with the publication
in 1974 of F. W. Winterbotham's The Ultra Secret and continued with extensive
declassification of original documents - sparked a great reevaluation of
wartime events. Most wartime decisions, operations, and events, even those
long considered settled, have had to be reconsidered, The ULTRA revelations
have also sparked a cottage industry of books, monographs, and articles based
on the wealth of original documents declassified over the past two decades. A
great many of these books have concentrated on the information content of
communications intelligence reports, relating newly released COMINT to a
particular commander, operation or theater.