You would appreciate the bit of sneaky deduction that Admiral Nimitz's codebreakers used to confirm that it was indeed Midway Island that the Japanese intended to attack.
They had intercepted Japanese messages and decoded them, but knew only that the target of the assault would be "AF." They suspected that AF might be Midway, but they had to know for sure. So, they instructed the commander of Midway Island to send out a radio message in the clear that his water distillation plant had broken down and that the island had an urgent need for fresh water. Shortly thereafter, a Japanese message was intercepted that reported "AF is short on water."
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(no subject)
Date: 2006-12-08 05:38 am (UTC)(no subject)
Date: 2006-12-08 12:44 pm (UTC)They had intercepted Japanese messages and decoded them, but knew only that the target of the assault would be "AF." They suspected that AF might be Midway, but they had to know for sure. So, they instructed the commander of Midway Island to send out a radio message in the clear that his water distillation plant had broken down and that the island had an urgent need for fresh water. Shortly thereafter, a Japanese message was intercepted that reported "AF is short on water."
Bingo.
(no subject)
Date: 2006-12-08 04:02 pm (UTC)In cryptography, that is known as a Chosen Plaintext Attack (http://en.wikipedia.org/wiki/Chosen-plaintext_attack). :-)
(no subject)
Date: 2006-12-08 04:05 pm (UTC)