In 1875 a German crypto book author published a cryptogram and promised to pay 100 Silvermarks to the first one who solved it. It’s probably to late now to win this prize, but I’m sure some of my readers are still interested in breaking this cryptogram.

Tobias Schrödel …

… , is known to many readers of this blog for his frequent appearances on Stern TV, a German TV magazine. Check here for an example. Tobias, who is a great speaker and comedian, is also known as Germany’s only comedy hacker.

On February 8, 2019, Tobias and I will give talks at the Kryptonight, an event organized by teacher Felix Brüstle at the Gymnasium Ottobrunn, a school in Ottobrunn near Munich. The Kryptonight is open for everybody, admission is free. Tobias and I hereby invite all readers of this blog who live in the Munich area to attend. The Kryptonight will start at 1900. Apart from the talks, there will be several showrooms with crypto devices and crypto puzzles. There is no Kryptonight website, but I will provide some additional information about this event on this blog soon.


The Carbonari cipher

Earlier this week, Tobias, who is also a crypto book expert and collector, informed me about a reprint of a crypto book from 1875 he recently purchased. It’s a book written in German titled Die Geheimschrift der Carbonari (“The Secret Writing of the Carbonari”).

The Carbonari (“charcoal makers”) were a network of secret revolutionary societies active in Italy from about 1800 to 1831. My Italian friend and crypto history expert Paolo Bonavoglia once told me about this organization and the ciphers they used.

The book Die Geheimschrift der Carbonari describes one of the ciphers used by the Carbonari – a variant of the Vigenère cipher. As most readers certainly know, the Vigenère cipher adds a keyword (e.g., LEMON) to the plaintext (e.g., ATTACK AT DAWN). Letters are added by interpreting them as numbers (A=1, B=2, C=3, …). If the result of an addition is greater than 26, 26 is subtracted. Here’s an example :

Plaintext:  ATTACK AT DAWN
Key:        LEMONL EM ONLE
Ciphertext: MYGPQW FG SOIS

However, the cipher described in Die Geheimschrift der Carbonari uses a different kind of addition. It is not clear how this addition works, as the original book contained an inlay that is missing in the reprint. Perhaps a reader can reconstruct this addition by looking at the following two examples given in the book:

Example 1:


Example 2:


In addition, the author writes that the Carbonari cipher can also be used with the keyword (e.g. WIEN) used again from the start for each plaintext word:

The addition used here is the same as above. So, I don’t know how it works. Here is the ciphertext that results from this encryption:



The challenge

The book ends with a cipher challenge:

According to the book text, the first person to break this encryption is awarded the sum of 100 Silvermarks. Here’s the transcription Tobias provided me:


I don’t know if somebody succeeded in deciphering this cipher text, but I’m pretty sure that now, after 144 years, it’s too late for winning the prize. Perhaps, my readers will try to break this cryptogram anyway. this might be difficult, as the algorithm used is only partially known, but I know that my readers are very skilled at solving mysteries like these.

Further reading: How Edgar Allan Poe broke about 100 ciphertexts


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Kommentare (14)

  1. #1 Thomas
    13. Januar 2019

    The cipher has been cracked by Hans Jahr on your blog, hasn’t it?

  2. #2 Klaus Schmeh
    13. Januar 2019

    @thomas: You’re right, sorry. I didn’t realize that I published this challenge already four years ago. Meanwhile I have written over 1000 blog posts, so I don’t remember everything I wrote.

  3. #3 Tobias Schrödel
    13. Januar 2019

    And also I have to say “Sorry” to Klaus, as I have send him the challenge. Of course, I had no idea, that you already wrote about it. Blame it on me … the beer at the Kryptonight is on me.

  4. #4 Klaus Schmeh
    13. Januar 2019

    @Tobias: It was not your fault.
    I’m sure, most of my readers don’t remember my article from 2015 (after all, I didn’t remember it myself). So, for most readers, this article is completely new 😉

  5. #5 Kerberos
    13. Januar 2019

    Another quite new thing to me are those “silvermarks” .
    Which country used this currency?

  6. #6 Klaus Schmeh
    13. Januar 2019

    >Another quite new thing to me are those “silvermarks” .
    >Which country used this currency?
    I have asked this question myself, but I can’t find any information online.

  7. #7 Dampier
    14. Januar 2019
  8. #8 Narga
    14. Januar 2019

    Germany had a currency called “Mark” during the Kaiserreich (issued 1873-1916) the coins were available in silver (0.2, 0.5, 1, 2, 3, 5 Mark) or gold (5, 10, 20 Mark).

  9. #10 Dampier
    14. Januar 2019

    Two fools, one thought, as we say in german : ]

  10. #11 Peter Lichtenberger
    Unter dem blauen Wolkenloch
    14. Januar 2019

    Funny: The award is in German Mark but the Book is printed in Austrian Capital Vienna…

  11. #12 Narga
    14. Januar 2019

    @Dampier: you must have posted a few seconds before me, I checked for new comments directly before I submitted 🙂

  12. #13 Thomas
    14. Januar 2019

    Since the German market promised more customers for Schneeberger’s cipher book than Austria, it’s no suprise the award was offered in Mark.

  13. #14 Kerberos
    15. Januar 2019

    gab es keine “Silvermarks”, in dem Buch wurden ja auch
    “Mark in Silber” ausgelobt, oddrr?
    Warum nun “in Silber”? Dazu fallen mir einige mögliche Hintergründe ein:
    – Münzen in 10 oder 20 Mark Stückelung konnten beim
    Einkaufen Probleme machen. Die meisten kleinen Geschäfte
    konnten darauf nicht herausgeben.
    – Goldmünzen hatten viele nie gesehen, man war
    mißtrauisch. Noch mehr bei Papiergeld.
    – Möglicherweise herrschte 1875 Knappheit bei
    Mark in Gold. Es mußten große Mengen der Landes-
    bzw Ländchenwährungen aufgearbeitet werden.
    Dabei dürften Scheidemünzen und Silber Vorrang gehabt
    haben, da “Alltagstauglicher”.
    – Evtl. nahmen Geldwechsler eine Gebühr.
    – Der Verlag (oder die Niederlassungen) hatten Einnahmen in Silber (Kolportage)
    und wollte den Gewinn daraus auszahlen.
    – Fällt jemand noch was ein?