Knowing that VIC was a "spy cipher" it is unlikely that the agents used a cryptographic device to genreate the 5 digit number but how did they do it?

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    $\begingroup$ Maybe a 10 sided dice? Sorry, could not resist that joke. $\endgroup$ – Maarten Bodewes Feb 20 '19 at 17:33
  • $\begingroup$ But actually it sounds like a possible way of generating that number, at least to me.Or am I completely wrong? $\endgroup$ – user65597 Feb 20 '19 at 17:37
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    $\begingroup$ No, dice are completely acceptable, but I wonder if they had 10 sided dice. Using dice or shuffling cards is of course completely possible. Even if you don't use 10 sides there are easy ways to accomplish the same thing with dice with a different number of sides. $\endgroup$ – Maarten Bodewes Feb 20 '19 at 17:41
  • $\begingroup$ I saw a scheme to create otps using two six sided dices on Dirk Rijmenants blog $\endgroup$ – user65597 Feb 20 '19 at 17:42
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    $\begingroup$ Human have a bias when selection random from their head. Not a good idea. $\endgroup$ – kelalaka Feb 21 '19 at 10:36

In the VIC cipher, that significant five-digit number was created by the user when doing the encryption. It was surely made on the spur of the moment without equipment. As you remarked, these people were spies, and they would not have wanted to get caught with some strange device.

The CIA's online library does not mention the five-digit number as a value that the user had to memorize. The agent already had four mnemonic keys stored in his or her mind:

 1. a date (in Russian this would be day/month/year; six digits)
 2. a snippet of a popular Russian song        (20 characters long)
 3. the user's personal identification number
 4. a Russian word (e.g., the word for "snowfall")

I do not know for sure, but I think it is most likely that agents came up with their own "random" number out of their own heads. One, admittedly thin, piece of evidence might be that the Russians were generating "one-time pads" at that time out of their own heads by pecking at a typewriter--and keys generated in such manner were considered "random" enough to encrypt important traffic.


Write the numbers 0 to 9 on slips of paper and draw them from a hat.

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    $\begingroup$ The system has auto-flagged this answer as low-quality due to its length. Could you please provide a citation or reference to support the claim that this is what spies using the VIC cipher actually did? (As the question is not what could they do, but what did they do) $\endgroup$ – Ella Rose Feb 22 '19 at 1:43

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