Pearl Harbor Revisited: United States Navy Communications Intelligence, 1924-1941

Appendix A. Naval Messages Intercepted between 5 September and 4 December 1941

This appendix contains seventy-two selected Japanese naval messages intercepted between September and 4 December 1941 by Navy intercept sites, at Hawaii, Guam, and Corregidor; these messages were not decoded and translated until September 1945-May 1946. At the end of the appendix are three diplomatic messages pertaining to the crisis which were translated on 8 and 30 December 1941. The Japanese naval messages are part of a total of 26,581 Japanese dispatches examined by U.S. Navy cryptanalysts.

The Japanese messages were originally discovered in a sanitized but unpublished group of 188 messages contained in a document obtained from the Navy Archives at Crane Indiana ...