3.2. Tokyo Sends More Orders about Destroying Cryptographic Material

Almost within a week of the transmission of the two Winds instructions messages, Tokyo began to send out more instructions to its diplomatic stations around the world concerning the destruction of cryptographic holdings and other sensitive papers. These new instructions, which were not all available to the Americans in a timely fashion due to the already slow processing of traffic using cryptographic systems like J-19 and PA-K2, in some instances appeared to contradict prior orders, while, in other cases, seemed to ignore the Winds directives.

3.2.1. The Hidden Word Message – A Complement to the Winds Messages

It now seems that the Japanese were not satisfied with just the ...

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