Thread

1. mmsc · 1790086381 · focus · HN ↗

   For anybody interested, the actual encrypted message:

     BTTE UM ANGABE DES MARSQWEGES X BEFINDE MIQ IN X ROSENOW ROSENOW X SOFORT FUNKANTWORT X WASCHBBSCH
   

   which, given misspellings, translates approximately to:

     Please specify the route of march. I am in Rosenow, Rosenow. Immediate reply by radio. Waschbusch.

   1. booty · 1790087929 · focus · HN ↗

          I am in Rosenow, Rosenow. 
      

      From the article:

          After trying many different approaches, GPT–6 
          Astra focused on using the repeated place name 
          ROSENOW ROSENOW as a crib. 
      

      This feels extremely underexplained! Why would Astra think to use that as a "crib"? Was it common to repeat the place name in these messages?

      (Is it possible that this is a misreported detail? It feels like a singular ROSENOW would be an equally effective crib)

      1. TheDong · 1790088530 · focus · HN ↗

         This was explained in the article right there:

         > it suspected that the plaintext of Nr. 173, SIPVX, might be related to the plaintext of the unbroken MVUEH message

         It makes sense that Nr. 172 and Nr. 173 might be related since they were sent at around the same time.

         In Nr. 173, "ROSENOW ROSENOW" was also present.

         It also makes sense that a longer crib would generally be more effective than a shorter one.

         1. booty · 1790091284 · focus · HN ↗

            It was partially explained by the article. It was not stated that ROSENOW was repeated in 173, and it was not obvious from the article text why ROSENOW would ever be repeated. Thus my curiosity.

            A sibling commenter explained it - Rosenow is both a municipal name and a district name, so naturally it would be repeated. (Like "New York, New York")

                It also makes sense that a longer crib 
                would generally be more effective than a 
                shorter one.
            

            It would seem to me that the odds of looking for even a single ROSENOW in the decrypted message would be plenty. The odds of a single ROSENOW randomly occurring in incorrectly decrypted output are vanishingly small. So it seems to me that looking for ROSENOW is a safer bet vs. looking for ROSENOW ROSENOW -- a single ROSENOW is a great sign you've got the correct key, whereas looking for ROSENOW ROSENOW seems like it would deliver false negatives (think of all the times we say "New York" rather than "New York, New York")

            I'm a novice at crypto though, so, maybe I've got that totally wrong.

            1. pkulak · 1790097629 · focus · HN ↗

               The reason a crib is useful is because the enigma can't route a letter back to itself. So, you can slide the crib along the message until no letters line up, and that's possibly where it is. If your crib is "the", that's not terribly useful, because it could exist anywhere. The longer the better.

               I ONLY know this because <a href="https:&#x2F;&#x2F;www.youtube.com&#x2F;watch?v=JsBZOcqZerk" rel="nofollow">https:&#x2F;&#x2F;www.youtube.com&#x2F;watch?v=JsBZOcqZerk, btw.

               1. pmarreck · 1790123598 · focus · HN ↗

                  I just happened to watch this one this morning! (But I guess it&#x27;s only a day old.)

                  Fascinating!

               2. Dunedan · 1790183475 · focus · HN ↗

                  It also got mentioned in Tom Scotts recent video about Bletchley Park, which is worth a view as well: <a href="https:&#x2F;&#x2F;www.youtube.com&#x2F;watch?v=tDLbO9KeddY" rel="nofollow">https:&#x2F;&#x2F;www.youtube.com&#x2F;watch?v=tDLbO9KeddY

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