TheCodeBreakers
discovered on December 7, Nagumo would decide whether or not to
attack. Strict radio silence was enjoined. Aboard the battleship Hiei,
Commander Kazuyoshi Kochi, a communications officer for the force,
removed an essential part of his transmitter and put it in a wooden box,
which he used as a pillow. The force drove eastward through fog, gale
winds, and high seas. No one saw them.
Meanwhile, Hull, after a frantic week of drafting, consultations, and
redraftings, had completed the American reply to Japan's proposal. It
called upon Japan to withdraw all forces from China and Indochina and
in return promised to unfreeze Japanese funds and resume trade.
Nothing was said about oil. On November 26, the day that he handed it
to Nomura, Tokyo circularized its major embassies with an open code.
While the winds code envisioned abolition of all communication with the
embassies, this new code—called the INGO DENPO ("hidden word") code —
annaabi.ee 
