Early in the second world war, Britain took its time to let America into the secrets of Ultra, the decryption of German secret communications by code-breakers at Bletchley Park.

第二次世界大战的早期，英国花时间让美国获知了Ultra的机密，这是电码译者在Bletchley Park破译的德国机密通信的译码。

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Indeed, America and Britain were so deeply penetrated that the Russians soon found out about Venona, changing their codes and cipher machines on October 29th 1948—"Black Friday" for code-breakers.

毫无疑问的，美国和英国非常清楚苏联很快就发现了Venona的存在，并更改了了他们的密码和密码机在1948年10月29号—译码者的“黑色星期五”。

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How would they know about our women prisoners of war, or female military astronauts and code breakers, and the courage of young African-American women soldiers during World War II?

WHITEHOUSE: We Started With A Dream

Prosecutors believe that other phone calls may be on Mr. Pellicano's computer hard drive, but code breakers haven't yet figured out how the detective may have encrypted those calls.

NPR: The Math Behind Pellicano's Code

Even while British code breakers were cracking the Enigma machine and altering the course of the war, Americans were developing one of the most secure, efficient forms of encryption, which was also one of the simplest.

FORBES: I've got a secret