And as soon as I read the decrypted message, I burned all of the cards.
When translated back from binary, this "a" is the final decrypted message.
National Security Agency documents contain decrypted messages from the Venona project, a wartime effort to crack the Soviet diplomatic code (www.
Such a scheme is called undeniable, since once the government has validated the message they cannot deny that it is the correct decrypted message.
The British secret services had been aware of Chapman's existence for some time, via Ultra (decrypted German messages), and would know his date of departure.
These came from decrypted German messages sent on the Enigma enciphering machine, and by 1944, the Allies were reading some of the messages in 'real time'.
Append the decrypted message to the document as a signature.
Venona (problems of using decrypted Soviet messages as evidence at court)
However, a second upgrade in mid-1943 was not and the flow of decrypted messages came to an end.
Tentatively making these assumptions, the following partial decrypted message is obtained.