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Verschlüsselte Postkarte: Wer kann sie (noch einmal) lösen

Von / 8. Juli 2014 / 10 Kommentare
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Ein US-Professor konnte vor Jahren einige alte verschlüsselte Postkarten knacken. Leider gibt es nur wenige Informationen dazu. Immerhin gibt es eine der Postkarten im Internet – ohne Lösung. Wer kann sie dechiffrieren?

2005 entdeckte die US-Studentin Emily Thielmann bei einer Freundin ein paar alte Postkarten. Diese waren verschlüsselt. Thielmann gab die Karten an den Kryptologie-Experten Professor John Holte vom Gustavus Adolphus College (Minnesota) weiter. Dieser versuchte sie zu lösen.

Wie die Leser von Klausis Krypto Kolumne wissen, sind verschlüsselte Postkarten keine Seltenheit. Vor Aufkommen des Telefons waren Postkarten das mit Abstand beliebteste Kommunikationsmedium, zumal das Porto vergleichsweise günstig war. So mancher Schreiber, der seine Mitmenschen nicht mitlesen lassen wollte, wendete Verschlüsselung an. Eine systematische Übersicht ist mir nicht bekannt, doch die in diesem Blog gemachten Erfahrungen zeigen, dass vor allem Verliebte Postkarten verschlüsselten – in aller Regel mit einfachen Verfahren, die sich heute vergleichsweise leicht entschlüsseln lassen. Am Ende des Artikels finden sich unter “Zum Weiterlesen” einige Beispiele.

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Im eingangs genannten Fall stammten die verschlüsselten Postkarten aus der Zeit um 1908. Sie wurden von einem gewissen Rev. Swan Hjalmar Swanson an seine Geliebte geschrieben. Alles, was ich über diese Geschichte weiß, stammt aus einer Veröffentlichung des Gustavus Adolphus College aus dem Jahr 2011. Leider sind die darin enthaltenen Informationen ziemlich dürftig. Ich habe sowohl das College als auch John Holte kontaktiert, doch leider erhielt ich keine Antwort.

Im Artikel sind zwei Seiten einer (derselben?) Postkarte abgebildet. Aus nahe liegenden Gründen konnte ich nicht um Erlaubnis für die Veröffentlichung fragen. Urheberrechtlich sollte ein so altes Dokument allerdings unkritisch sein.

Postcard-Swanson

Postcard-Swanson-2

John Holte konnte diese und einige weitere der Postkarten dechiffrieren. Er hatte wohl wenig Mühe damit, da er es mit einer einfachen Buchstabenersetzung zu tun hatte. Über den Klartext und über die weiteren verschlüsselten Postkarten habe ich keine Informationen.

Mich würde nun interessieren: Schafft es jemand, die Verschlüsselung zu knacken? Es sollte relativ einfach sein und ist ja mindestens einmal bereits gelungen. Bessere Scans gibt es hier und hier. Wenn jemand mehr über diese Geschichte weiß, würde es mich ebenfalls interessieren.

Zum Weiterlesen:

Verschlüsselte Postkarte aus dem Jahr 1906 gelöst

Von der NSA entschlüsselt: Zwei verschlüsselte Postkarten aus dem Ersten Weltkrieg

Neuchâtel-Kryptogramm: Eine rätselhafte Postkarte aus dem Jahr 1915

Zwei verschlüsselte Postkarten aus dem Jahr 1912: Wer kann sie knacken?

Stichworte:
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Kommentare (10)

  1. #1 Delia Huegel
    8. Juli 2014

    Hi, Klaus,
    Count on me if it is a very simple substitution cipher. So it goes:
    “Began school to-day with ?? children./ I guess they are pretty good/ too. I have one little girl/ by the name of Marybyt she is/ afraid of me. Stra(n)ge isnt it?/ I like Moscow all-right. I am spending/ all my spare time writing poetry/ mostly about you dear.
    With lots of love/ from ME”
    On the other side:
    “I guess we are not the only/ ones who have thought that/ those days are shoot.”

    As I see, there is a town in Minnesota called Moscow, south from Mahtowa, the town mentioned in the address and on the postal stamp.

  2. #2 Rich SantaColoma
    8. Juli 2014

    Delia beat me to it… I have as the back, “Began school today. With ** [cj in plaintext?] Children. I guess they are pretty good- see- I have one little one by the name of Mary but she is afraid of me- strange, isn’t it? I like Moscow all right. I am spending all my spare time writing poetry, mostly about you dear. With love of *** orot me.

  3. #3 Rich SantaColoma
    8. Juli 2014

    Oh… “with love from me”… not sure why I put a “t” for the “m”. but the f/o thing got me, too…

  4. #4 Dario aus Italien
    Pisa, Italien
    8. Juli 2014

    Well, I wanted to post my first comment on this column with the solution of this really easy task, but it was too easy and I was beaten. I will add some observations:

    1) A colon is used instead of a space to separate words, but commas, full stops and the like are kept as in normal writing, so I read … “a little girl by the name of Mary, [comma] byt [writer’s mistake: should be “but”] she is afraid of me ­- strage [second mistake: should be “strange”] isn’t it? …”

    2) My guess, as good as any other, is that “cj” stands for “30”, with the straightforward substitution a->1, b->2, …, h->8, i->9, j->0. A class of 30 children is rather plausible. Well, it could be a->0, …, j->9, which would yield an equally plausible number of 29 children, but somehow I’d expect a teacher of little children in 1908 to start counting from one and not from zero.

    3) Unfortunately but not surprisingly, we don’t have examples of Q, nor X, nor Z in the text and we cannot know how they would be written.

    I could write this in German too, but I don’t expect many Germans to be reading this at the moment, with Germany swiping Brasil away 7 to 0… congratulations 🙂

    Grüße aus Italien,
    Dario

  5. #5 Delia Huegel
    8. Juli 2014

    Congratulations. Epic match

  6. #6 Klaus Schmeh
    9. Juli 2014

    Delia, Rich, Dario:
    Thank you very much for solving this cryptogram!!! Almost as sensational as the 7:1 win of the German team in Brazil.

  7. #7 Dario aus Italien
    9. Juli 2014

    Oh, and about the shorter text on the other side: the last word is certainly “short” and not “shoot”: the two “runes” are similar but clearly different, so it reads “I guess we are not the only ones who have thought that those days are SHORT.” However, there is probably another message hidden more deeply here. Instead of the colon which separates words in the longer message, there are two dots above the first “I” and, most importantly, the words in the shorter message are separated by different symbols. If we transcribe the first of those symbols as “1”, the second as “2” and so on, they appear in the order 11122341211×152. The “x” stands for no separator between “that” and “those”, which are on different lines. Those symbols are important: “only” and “ones” are on different lines too, but what I transcribed as “4” was written beside “ones” on the new line. Maybe _this_ was indeed the secret message…

    Grüße aus Italien
    Dario

    • #8 Klaus Schmeh
      9. Juli 2014

      Thanks for this note. “short” certainly fits better than “shoot” (although some Americans use “shoot” as a replacement for another word starting with “sh” and ending with “t”).

      • #9 Rich SantaColoma
        9. Juli 2014

        I agree on “short”, also… it was what I came up with. I think that sentence is one lover lamenting that the time they had together was very short, and he was relating to the postcard’s saying in that way.

        I really enjoy your postcards, and the messages… the subtlety of expressions of love at this time are a pleasant contrast to modern “sexting”. I think it carried more impact, to say your time together was too short, and that you were writing poetry about the person, and just that you were thinking of them… than any number of crudities we might find, today, in a text message.

        Although perhaps such subtleties were reserved for the more visible postcards… perhaps the letters got down to business!

  8. #10 Dario aus Italien
    9. Juli 2014

    I think there is a reference to the postcard theme “The shortest day in the year” with lovers…

    It is possible that the two pictures represent two different cards with two different versions of the code. The longer message is probably in an older version, with clearly separated words, offering a lot of cribs (I started with “isn’t it”). The shorter message would then be in a slightly more difficult version, with randomly chosen nulls hiding word boundaries. I am now leaning toward this explanation, instead of the second layer of hidden messages I was speculating upon in my previous comment.

    Grüße aus Italien
    Dario