The Rohonc Codex, one of the world’s most famous crypto mysteries, appears to have been solved. And yes, I believe this solution is correct.

The Rohonc Codex is a handwritten and hand-illustrated book with about 450 pages. It’s a unique piece. The special thing about it: The Rohonc Codex is written in a mysterious script. All attempts to decipher the text in the codex or to make any other sense of it have failed for at least 150 years. The Rohonc Codex is therefore considered the second most important unsolved book cryptogram after the Voynich Manuscript.


The Rohonc Codex is, of course, contained in my (now outdated) top 25 list of unsolved cryptograms. In addition, it is number 00002 on my Encrypted Book List. The Rohonc Codex could undoubtedly be a world-famous, much-discussed crypto mystery – if the world-famous, much discussed Voynich Manuscript did not exist.

Earlier this week, I received a mail that informed me about a new article in Cryptologia (published on May 28, 2018).


According to this article, the Rohonc Codex has now been solved. And this solution doesn’t look like nonsense.

Today, I am going to present an FAQ about the Rohonc Codex and the recently published solution. In a later post, I will address the solution in detail.


Who wrote the Rohonc Codex?

The author of the Rohonc Codex is unknown. In contrast to the Voynich manuscript, there is not even much speculation on this subject.


Where was the Rohonc Codex created?

The Rohonc Codex most likely originates from Central or Eastern Europe. The place of origin cannot be narrowed down much more precisely.


What do the pictures of the Rohonc Codex show?

While the illustrations of the Voynich manuscript leave much room for interpretation, to say the least, the motives of most of the images in the Rohonc Codex can be identified. Almost all of them show scenes from the Bible – for example, Jesus on the cross or Moses on Mount Sinai.



What was the purpose of the Rohonc Codex?

It is completely unclear what the intended purpose of the Rohonc Codex was. The Christian images suggest a religious use. Perhaps a religious dissenter wanted to hide his heretical doctrine from the church by encryption. On the other hand, the pictures could just be a cover to distract from the actual content of the book. It is also conceivable that the author chose a religious text to demonstrate a writing system he had invented (like Johannes Gutenberg, who demonstrated the printing technology he had invented using a religious text, namely the Bible). After all, it is also possible that someone created the Rohonc Codex just to sell it to a collector for a lot of money.


What are the most important theories about the text in the Rohonc Codex?

The text of Rohonc Codex could be …

  • … ordinary text written in a script that is no longer known today
  • … encrypted text
  • … a hoax

The same is true for the Voynich Manuscript.



Are the pages of the Rohonc Codex available as scans on the Internet?

Yes, here they are:


Where can I find more information about the Rohonc Codex?

While there are stacks of literature on the Voynich manuscript, much less has been published about the Rohonc Codex. To get started, I recommend an article I wrote for the Centre for the Study of Manuscript Cultures (German/English). There is also a chapter about the Rohonc Codex in my book Nicht zu Knacken. The most detailed source is the article Why don’t we decipher an outdated cipher system? The Codex of Rohonc, which was published in 2010 in Cryptologia. The author of this excellent work is Benedek Láng from Hungary.

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Kommentare (9)

  1. #1 George Lasry
    3. Juni 2018

    I read the first paper and it looks sound and scholarly. The decrypted text segments have features that could not be easily created by rubbish pseudo-decryptions, as it is often the case with other claimed decryptions. Looks very promising. Eagerly waiting for the next 3 papers.

  2. #2 Rich SantaColoma
    4. Juni 2018

    Well this is certainly wonderful and historic news! I look forward to seeing the decryption, and finally knowing what is in this book.

    I’ve also been aware of many failed attempts on this work, as there have been on the Voynich, and in so many other cases… but with endorsements like Klaus, Benedek, Craig and now George, I am especially hopeful the solution has finally been reached for the Rohonc.

  3. #3 Charlotte Auer
    4. Juni 2018

    Ganz ehrlich gesagt, finde ich es etwas mehr als voreilig, den Rohonc Codex hier als gelöst zu deklarieren, obwohl es weder eine vollständige Transkription noch eine überzeugende Feststellung der zugrunde liegenden Sprache gibt und die angekündigten Folgeartikel naturgemäß noch auf sich warten lassen. Nur um mal die grundlegenden Mängel zu benennen, vom Rest ganz zu schweigen.
    Aus meiner Sicht ist diese Handschrift noch lange nicht schlüssig und unwiderlegbar entziffert. Ganz abgesehen davon, dass ich diesen Ansatz ohnehin nicht für realistisch halte. Was aber nichts daran ändert, dass von einer Lösung bislang nicht die Rede sein kann.

  4. #4 Thomas
    4. Juni 2018

    Can a solution be reliably judged as long as only its first part is published? Let alone the inconsistencies in the number system of the solution,

  5. #5 Michael
    4. Juni 2018

    “I will describe the solution in a later post.”

    Click bait.

    Ganz schön frech von Ihnen so aufzutreten.

  6. #6 Peter
    5. Juni 2018

    Unfortunately, this article doesn’t live up to the expectations its headline fuels. It provides no new information about the codex and no explanation about the alleged solution at all. Disappointing!

  7. #7 Torsten Timm
    5. Juni 2018

    Kiraly and Tokai describe there decipherment as “an extremely heuristic task.” Such a statement in the summary already rises a big red flag. They also say “that one symbol signify one thing” and that there decipherment has “various degrees of certainty”. Such statements sound like the justification for an interpretation.

    As far as I understand they have deciphered the text on word level. With other words they assume that a codebook was used to encode the manuscript and that each symbol or combination of symbols stands for a word or an idea.
    For deciphering this kind of text the plaintext or the codebook used for encoding the Rohonc Codex is needed. It seems that the authors try to reconstruct the codebook by using the drawings in the manuscript as hints for the plaintext. Since the drawings refer to scenes from the bible it seems logical to use the bible as plain text. If this is indeed the case the problem would be to find some independent confirmation for there interpretation. Since they have used the bible to construct the codebook it would be questionable if the same text is also used to confirm there interpretation.

    It would be necessary to demonstrate that there result is much better then for a randomly chosen plaintext. Unfortunately a statement like “various degrees of certainty” already indicates that the bible as plaintext does not always seem to fit very well.

  8. #8 Rich SantaColoma
    5. Juni 2018

    Torsten: Your observations and comments mirror what I thought, too… including your “red flag”.

    If they have surmised the correct words, though, I would not necessarily think this would have to point to use of a code and code book. Because there is not yet a revealed cipher system, I don’t think, necessarily demands this conclusion… yet.

    Also, although the meaning of the word may be correct, I don’t yet see an assumed language. Considering this, perhaps there is still a system at the character level, which would encipher whatever language this is into the resulting cipher words? I mean, there are meanings of words only, so far, NOT spellings… and perhaps when different languages are tried for those meanings, it will give an insight into some possible cipher. Perhaps this is where the authors are going next, I don’t know.

    Certainly, if this is the case, they have worked backwards in deriving word meanings first… but if they did, and it works, that would be an interesting and helpful method to keep in mind for other problems.

  9. #9 Nick Pelling
    6. Juni 2018

    Hi Klaus, as I blogged, it’s a bit early to shout that the Rohonc Codex has been cracked. It may well be that they have caught sight of a (part of a) Rohonc Rosetta Stone, which alone is well worth reporting, but I think there is still a great deal of work yet to be done.