151 (Memoranda from Captain L. F. Safford) from the Hewitt Inquiry has a copy of the U.S. Navy message OPNAV-242239 'Evaluation of Messages of 26 November 1941' which has in part: '1. Reference (a) advised that Com 16 intercepts were considered most reliable and requested Com 16 to evaluate reports on Japanese naval movements and send dispatch to OPNAV, info CINCPAC. Com 16's estimates were more reliable than Com 14's, not only because of better radio interception, but because Com 16 was currently reading messages in the Japanese Fleet Cryptographic System ("5-number code" or "JN25") and was exchanging technical information and Japanese-to-English translations with the British unit (the Far East Combined Bureau) then at Singapore. Lt. Cdr. Arthur H. McCollum was aware of this, and it may have been part of his thinking when he drafted the McCollum memo. Duane L. Whitlock, traffic analyst at CAST, was not aware before the attack IJN movement traffic code was being read. "Reading" in this context means being able to see the underlying code groups, not breaking out the messages into usable plaintext. The Hewitt Inquiry document also states, "The "5 numeral system" (JN-25B) yielded no information which would arouse even a suspicion of the Pearl Harbor raid, either before or afterward." Detailed month by month progress reports have shown no reason to believe any JN-25B messages were fully decrypted before the start of the war. Tallied results for September, October, and November reveal roughly 3,800 code groups (out of 55,000, about 7%) had been recovered by the time of the attack on Pearl Harbor. In all, the U.S. intercepted 26,581 messages in naval or related systems, not counting PURPLE, between September and December 1941 alone. So convinced were U.S. Navy planners Japan could only stage a single operation at a time, after intercepts indicated a Japanese buildup for operations in the Dutch East Indies, for more than two weeks (between 1 November and 17 November), no JN-25 message not relating to that expected operation was even examined for intelligence value. Japanese intelligence Japanese espionage against Pearl Harbor involved at least two Abwehr agents. One of them, Otto Kuhn, was a sleeper agent living in Hawaii with his family. Kuhn was incompetent and there is no evidence he provided information of value. The other, Yugoslavian businessman Duško Popov, was a double agent, working for the XX Committee of MI5. In August 1941, he