united states cryptologic history | ||
Pearl Harbor Revisited: | ||
United States Navy Communications Intelligence, 1924-1941 | ||
CH-E32-94-01 | ||
national security agency central security service |
CENTER FOR CRYPTOLOGIC HISTORY
NATIONAL SECURITY AGENCY
1994
Earliest Efforts
Role of ONI
Early War Plans
Japanese Fleet Capabilities and Intentions
Cryptologic Challenge: Navy-Army Cooperation
Bureaucracy Prevails
Status Quo in the Pacific
A New Attempt at Cooperation
Japanese Cryptography
Recovering the "Blue Book"
Introducing JN-125
Turning Victory into Defeat
Introducing "Purple"
Disarmament: Paying the Price
Confusing Diplomacy
Struggling for Resources
Planning for War
War Games
Pacific Buildup
National Emergency
Circumstances Favor Diplomatic Targets
Information Gaps
Cooperation with Allies
The Move to Hawaii
Support to the Pacific Fleet
Japanese Intentions Revealed
Support to the Asiatic Fleet
Japanese Strategy
Japanese Navy
Diplomatic Messages
Warning Messages
Reaction
Comint After the Opening Attack
Conclusion
Appendix A: Naval Messages Intercepted between 5 September and 4 December 1941
Appendix B: Summary of Diplomatic Messages, July-November 1941
Appendix C: Highlights from COM-14 Daily COMINT Summary