In the novel Mathias Sandorf by Jules Verne the use of a Turning Grille is described. Does a reader know other encrypted messages of this kind?

In Trieste, 1867, two petty criminals, Sarcany and Zirone, intercept a carrier pigeon. They find a ciphered message attached to its leg and uncover a plot to liberate Hungary from Habsburg-Austrian rule. The two meet with Silas Toronthal, a corrupt banker and form a plan to deliver the conspirators to the police in exchange for a rich reward. The three Hungarian conspirators, Count Mathias Sandorf, Stephen Bathory and Ladislas Zathmar are arrested and sentenced to death. Only Sandorf can escape.

This is, according to Wikipedia, how the novel Mathias Sandorf (published in 1885) by Jules Verne starts. The “ciphered message” mentioned in this summary is the following:


Later, Sarcany und Toronthal find the following turning grille (also known as Fleissner grille) in the desk of the receiver:


How a turning grille works

Here’s how a turning grille works (the stencil is used four times, each step is followd by a 90 degree turn):


A turning grille encryption represents a transposition cipher. This means that no letter substitution takes place. Instead, the order of the letters is changed. To construct a turning grille one can proceed as follows (start with a square matrix and fill it with numbers from 1 to 4 at random):


Decryption of the message in the novel

Each of the lines of the Mathias Sandorf message has 36 letters. We therefore can use the grille once per line. We get:


Read backwards this message reads as follows: “Tout est prêt. Au premier signal que vous nous enverrez de Trieste, tous se lèveront en masse pour l’indépendance de la Hongrie. Xrzah.”

This is the text Jules Verne used in the original edition, which was written in French. In the English and the German edition I checked the message is the same; it was not translated.

There’s an interesting website made by German crypto professor Klaus Pommerening, who explains how this message can be broken. It goes without saying that using the same grille three times in a row is not a good idea.


Other turning grille uses

Turning grilles were not only used in novels. Here’s a list of other uses I am aware of:

  • Dutch crypto history expert Karl de Leeuw solved a turning grille message received by the Dutch Stadtholder William V.




  • Bill and Jew-Lee Briere created a turning grille puzzle, which is inspired by the Friedman’s Christmas card. Can you solve it without knowing the grille?


Now my question is: Are there other uses of the turning grille? In the book Decrypted Secrets by Friedrich Bauer it says that this encryption method was used in the 18th century, for example in 1745 in the administration of the Dutch Stadthouder William IV. Later. The mathematician C. F. Hindenburg studied turning grilles more systematically in 1796. Bauer also mentions the use of grilles (named ANNA, BERTA, CLARA, DORA, EMIL, and FRANZ) by the Germans in WW1.

Does a reader know more?

Further reading: How blog reader Norbert Biermann solved the Reihenschieber challenge


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Kommentare (26)

  1. #1 Bill Briere
    Wyoming, USA
    4. Dezember 2017

    My wife and I still have some extra Cryptocablegrams to give away. (See the last grille example pictured above in this post.) These were among several freebies that we made for the Friedmans’ 100th wedding anniversary celebration that we hosted at the (U.S.) National Cryptologic Museum at the end of the 2017 Symposium on Cryptologic History.

    We would be happy to send one (including an attached grille) — plus a wooden commemorative token and a cryptogram bookmark — to any of Klaus’ blog readers, through December 31, 2017, or until our supply is gone.

    Send your name and mailing address to:, and we’ll send them to you at no cost. If you want to reimburse us for whatever the postage was, you can do that through PayPal, but only if you’re pleased with these humble puzzles when they arrive. (Some have asked if we can send these to addresses outside the U.S. … Yes!)

  2. #2 TWO
    4. Dezember 2017

    For strategic reasons I will not attempt to solve the Briere-Lann challenge.

    But imho the spaces are the weak spot……



  3. #3 Paolo Bonavoglia
    4. Dezember 2017

    Klaus: thank you for mentioning this 1916 Fleissner grille cryptogram: it’s very likely one of the grilles used by the Germans in WW1 and mentioned by Bauer, Kahn and Sacco himself in the 1947 edition of his manual. Most transposition cryptograms decrypted by Sacco in 1916 seem to come from the German-Rumanian front near the Danube and Black Sea; some has place names, like this one:

  4. #4 Klaus Schmeh
    4. Dezember 2017

    Bart Wenmeckers via Facebook:
    Paolo has since written up his grille here. I contributed to the machine solving section. (Crittanalisi automatica)

  5. #5 TWO
    4. Dezember 2017

    Not trying to solve it but I think the O = E

  6. #6 TWO
    5. Dezember 2017

    it ends with Love!

  7. #7 TWO
    5. Dezember 2017

    To the

    (im only pretending to solve this 😉

  8. #8 Ralf Bülow
    5. Dezember 2017

    Austrian Crown Prince Rudolf (who killed himself and his lover at Mayerling) used a Fleissner grille, according to Bauer, viz. (sorry for the paywall)

  9. #9 Thomas
    5. Dezember 2017

    Is it possible to solve the turning grille puzzle without any hill climbing algorithm, i.e. only with pencil and paper/transparent foil? I suppose that the usual anagramming doesn’t work because of the additional substitution. It is clear that there are 9/7/5/3 holes in the four concentric squares of the stencil resp. 6 holes in each segment, but there isn’t sufficient information to locate every hole. Up to now I only have managed to reveal a part of the stencil (holes and places where no holes can be) and small fragments of the text which are to short to break the substitution.

  10. #10 dedickeBom
    5. Dezember 2017

    even without this riddle , I recommend this extraordinary book. You never have read about such a strange journey.

  11. #11 S.Tomokiyo
    6. Dezember 2017

    Two of my articles deal with turning grilles, related to Alexander Hamilton and a US Civil War Confederate agent.

    I think the grille mentioned by Friedrich Bauer refers to the same one solved by Karl de Leeuw. It was found in William V’s archive but probably belongs to the time of William IV.

    C. F. Hindenburg’s work of 1796 must be Fragen eines Ungenannten uber die Art durch Gitter geheim zu schreiben (Google), in which an example is given on p.348 but I cannot read the old German type. Would anyone explain the text?

  12. #12 Thomas
    6. Dezember 2017

    @S. Tomokiyo
    This short article seems not to be a systematic study as mentioned by F. Bauer. Hindenburg only shows a grid cipher given to him by someone who wanted to know if such a grid cipher method is worth being published. In his explantory note he only says that the horizontal and vertical lines separating the letters have been left out in the printed version for reasons of the book format. Neither the kind of the grid nor the solution is given.

  13. #13 Thomas
    6. Dezember 2017

    This is Hindenburg’s profound article on turning grilles (volume of 1796):|LOG_0018&physid=PHYS_0093. A copperplate showing the grid with numbered edges (1 – 4) was inserted in the book (but isn’t part of the scan). Hindenburg calls it ‘Dlandolfsche Chassis’. So the turning grille wasn’t Fleisser’s invention? The question remains who Dlandolf (if I’m not mistaken, the first uppercase letter of the name on p. 83 is no ‘O’ but a ‘D’, although this sounds peculiar to me).

  14. #14 Thomas
    6. Dezember 2017

    Correction: It is the volume of 1798 which contains the article ‘Ueber Gitter und Gitterschrift’ (Starting on p. 81, image on p. 84). The link above doesn’t work properly because it isn’t completely underlined. Another try:|LOG_0018&physid=PHYS_0093 (hope it works, otherwise type it in).

  15. #15 Thomas
    6. Dezember 2017

    Hindenburg’s source was the French author Dlandol who described ciphers used by Royalists during the French revolution: Unfortunately this very interesting book isn’t easy to get.

  16. #16 Thomas
    6. Dezember 2017

    The turning grill cipher is also explained in Leo’s ”Mysterienbuch alter und neuer Zeit oder Anleitung geheime Schriften lesen zu können, geschwind und kurz schreiben zu lernen, ingleichen Chiffern aufzulösen’ from 1797 (, see p. 36). Leo referres to Hindenburg’s articles and supposes that French grille ciphers by Vigenere and Dlandolf had inspired Hindenburg concerning the turning grill. Vigenere ( and, according to Hindenburg, also Dlandol only had developed non turning grilles with apertures for entire words. So it was probably Hindenburg who had invented the turning grille cipher nearly 100 years before Fleissner von Wostrowitz did it).

  17. #17 Thomas
    6. Dezember 2017

    Oh, now I see a turning grille had been used already in 1745 by William IV in the Netherlands, so Hindenburg seems to be the first who described this method.

  18. #18 S.Tomokiyo
    7. Dezember 2017

    You are right. I should have referred to “Ueber Gitter und Gitterschrift”. I have its copy printed out from Google years ago but I lost the link and failed to mention it. Thanks to the title you give, I could find another copy at Google.

    A copy of Dlandol’s book can be read on Google (at least here in Japan). The content seems to be rudimentary. A non-turning grille (with apertures for entire words) is described in Part I, Chapter III (pp.26-28).

  19. #19 TWO
    7. Dezember 2017

    I used Bill and Jill’s grille on K4 and look what showed up 🙂
    T O T H E P E O P L E
    O F T H E C E N T R A
    L I N T E L L I G E N
    C E A G E N C Y I N V
    I T A T I O N M E E T
    U S A T T H E O B E R
    L I N C L O C K B R I
    N G C O L D B E E R A
    N D P I Z Z A J S

  20. #20 Klaus Schmeh
    9. Dezember 2017

    Here’s the substitution Bill and Jew-Lee used in addition to the grille:
    Knowing this, it should be a lot easier to break the message.

  21. #21 TWO
    9. Dezember 2017

    What happened to cipher letter T equals plain letter I?

  22. #22 Bill Briere
    Wyoming, USA
    9. Dezember 2017

    All will be revealed below. ***Spoiler alert for the Cryptocablegram***

    The “solution” posted in Comment 19 has absolutely no connection to our puzzle. And the key posted in Comment 20 may have caused some confusion. So, I’ll just go ahead and clear the air here.

    Both the transposition and substitution parts of the puzzle are trivial to solve. We designed it to be a fun challenge achievable by most anyone. However, a physical grille is required. Since that grille is absent here, the challenge has been bumped up to a difficulty level beyond the reach of the amateur pencil-and-paper cryptanalyst. The grille that all of you are missing is included with the hardcopy version of this puzzle, and it’s available on request, as previously noted.

    Our grille is identical to the one used by the Friedmans on their 1928 Christmas telegram card.

    When it is applied to the Cryptocablecablegram, a substitution cipher is revealed. The plain component of the key is a direct standard alphabet; and the cipher half is a keyword-mixed alphabet. The keyword is FRIEDMAN, and the two alphabets are shifted to align at B(p) and J(c). (Sort of a sneaky way to sign it with our initials.)


    With this information, the solution is right around the corner.

  23. #23 TWO
    10. Dezember 2017

    If you see message #19 as a solution you are crazy as a bat 🙂

  24. #24 TWO
    10. Dezember 2017


    Simple transposition and T = I. ?

    Very misleading information if you ask me…..

  25. #25 TWO
    10. Dezember 2017

    D Z D S O E C Y O seems to decode to :

    To the Syne


  26. #26 TWO
    10. Dezember 2017

    Probably rife with errors

    A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
    H J K L O P Q S T U V W X Y Z F R I E D M A N B C G

    / W V D Z Z T . Y T
    O / E Y E V . T E / /
    D Y / S X O H . / Q P
    Y O L / . . X / Z H I
    Q I W T / / / O H L E
    M T W O / / / L E . .
    X E H O / / / E Y . E
    W X H / Y : Z / Z Q O
    H . / . Y W . M / X K
    D / M T E W X O C / Y
    / E O V . C ! . K D /

    / L K T O O I . N I /
    E / S N S K . I O / /
    T N / H M E A . / G F
    N E D / . . M / O A R
    G R L I / / / E A D S
    U I L E / / / D S . .
    M S A E / / / S N . S
    L M A / N : O / O G E
    A . / . N L . U / M M
    T / U I S L M E Y / N
    / S E K . Y ! . C T /