# A crypto competition from 1875

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:

```TheodorHuberfallirtdieserTagegewisssalvirteuch
romaromaromaromaromaromaromaromaromaromaromaro
----------------------------------------------
yhimoavtxnijmobpjxtxjkuwavmuniiejwvirdrsavigyh```

Example 2:

```TheodorHuberfallirtdieserTagegewisssalvirteuch
abrahamabrahamabrahamabrahamabrahamabrahamabra
----------------------------------------------
hunmemvthqwqvmpqjjoxewjnjoagwvnezivibgfzjtwhpt```

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:

FAAHLLN UBEWUGLJW WHAC VETJCWKATLL
BUNVFGXV JUNKAEMIVIXQ EABMWBR KWKJLXAWE ICLSTLF

### 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:

truqnujkbtvfqajaoa
jnqgqwlbdrtmdeavab
asnnqljxcwfislmamm
tnhncwmamqwaxtupg
at

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.

## Kommentare (14)

1. #1 Thomas
13. Januar 2019

@Klaus
The cipher has been cracked by Hans Jahr on your blog, hasn’t it? http://scienceblogs.de/klausis-krypto-kolumne/2015/02/13/eine-kryptologische-preisaufgabe-aus-dem-jahr-1875/(#7)

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
München
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.

5. #5 Kerberos
13. Januar 2019

Another quite new thing to me are those “silvermarks” .
Which country used this currency?
:=)
Gruß
Kerberos

6. #6 Klaus Schmeh
13. Januar 2019

@Kerberos:
>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
dampierblog.de
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). https://en.wikipedia.org/wiki/German_gold_mark

9. #9 Dampier
dampierblog.de
14. Januar 2019
10. #10 Dampier
14. Januar 2019

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

11. #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…

12. #12 Narga
14. Januar 2019

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

13. #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.

14. #14 Kerberos
15. Januar 2019

Natürlich
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?
Gruß
Kerberos