Ist das Dorabella-Kryptogramm eine Fälschung?

Kommentare (14)

1. #1 frbr

   26. Februar 2021

   Diese Engländer: leben rückwärts, So wie Merlin aus Th.Th.White. Edward Elgar (1957-1934)

2. #2 Tobias Schrödel

   München

   26. Februar 2021

   OH NOOOO … don’t do this to me. The Dorabella cipher is and has always been one of my favourite ones 🙂
   How ever, Thomas, your thoughts have many good points and observations. I start to doubt …

3. #3 Klaus Schmeh

   26. Februar 2021

   @frbr:
   Danke für den Hinweis. Ich habe das Geburtsjahr korrigiert.

4. #4 Hubert J. Farnsworth

   27. Februar 2021

   Zeichnet doch mal Notenlinien ein. Könnte ein Musikstück sein.

5. #5 ShadowWolf

   There are many who doubt

   27. Februar 2021

   You skipped Keith Massey.
   http://aplaceofbrightness.blogspot.com/p/introduction-in-1897-british-composer.html

   He didn’t think his arguments through and you can turn his arguments around to prove a correct key. I suspect you can also turn this pattern argument around and prove a correct key in a similar way. I can make those patterns appear in any more or less normal English text. It is an odd effect of the key arrangement and the symbols. You won’t see a pattern at all without a similar symbol based alphabet.

   Some would say that the date in Elgar’s handwriting is proof enough. You have to also wave away the cipher examples from Elgar’s notes and the Liszt fragment if you want to insist the Dorabella cipher is forged.

   The notion that the cipher is anything other than substitution is also false. If you transcribe it wrong, it will lead you down false paths. I actually read your paper with the consonant lines etc. As little as two errors will cause my own hill climber to fail in finding a 100% decrypt. If I remember correctly your transcription has about 6 errors.

   So first, you need to start with the correct transcription:
   ABCDE FGDHI JKLMK NKKFB BKMOI OPJQG KGFGD HRDCK KCFPL GKJKF SQLMO HHOJQ CQFSQ CMSTP QCKFS LQMDB PQFDM OD

   It is a mono-alphabetic substitution cipher with a somewhat non-traditional key phrase based key. (3 words but knowing how Elgar wrote, it may actually be a whole phrase.) Do a frequency count. The Index of Coincidence is close enough for such a short message. E occurs 11 times. TH appears 3 times. Some words are spelled in a phonetic fashion and some are abbreviated, but enough are mostly normal. K is not used, but C is. But you probably won’t get more than about a 70-80% solution by hand without more help. This is why Bletchley Park used it as a cipher test. This should give you enough text to find a decrypt in a hill climber output list.

   Feed that into Cryptool2 using the genetic search with the dictionary setting. If you don’t get it on the first try, try again. It will show about a 95% correct decrypt that will match the pencil and paper work. My own hill climber using a privately collected corpus finds a 100% decrypt and another hill climber also finds about a 95% partial decrypt. None of the false positives from the hill climber will produce a keyword based key. If you want to try this with other hill climbers, I suggest using 4-grams for the search. Using 5-grams doesn’t usually work and only one corpus, so far, will generate 2 grams and 3-grams that work.

   The Dorabella cipher has been solved for nearly two years. My biggest problem is no one is willing to actually examine the facts and many quickly render opinions without examining all of those pesky facts.

   Perhaps the paper I submitted to the ICHC (Histocrypt 2021) will be accepted and someone will finally listen rather than judge with personal prejudices. My solution is the only one that will stand up to a room full of cryptanalysts because there are no tricks involved.

6. #6 Thomas

   27. Februar 2021

   @Klaus

   Außer den beiden von dir oben verlinkten Notizen gibt es noch eine weitere mit ähnlichen Zeichen: http://www.sothebys.com/de/auctions/ecatalogue/2016/music-continental-russian-books-manuscripts-l16402/lot.92.html. Da die Zeichen zusammen mit einer 3 hinter dem Pfund-Zeichen (der Preis der Gagliano-Geige) stehen: Spricht das nicht für Zahlenzeichen?

7. #7 Norbert

   27. Februar 2021

   @Thomas: danke für den Link, sehr interessant! Die “3” könnte meines Erachtens auch ein Symbol der Dorabella-Chiffre sein. Die Wiederholungen von “£” und immer den drei gleichen Symbolen wirken auf mich sehr verspielt. Vielleicht war es wirklich einfach so, dass Elgar seine Freunde allgemein oder Dora speziell eine Zeit lang mit dieser Chiffre aufzog, indem er ihnen/ihr damit “verschlüsselte” Nachrichten zukommen ließ, die gar nicht entschlüsselt werden konnten, weil sie keine Bedeutung hatten? Ich kenne Menschen mit dieser Art Humor …

   @ShadowWolf: Thank you for the link to Keith Massey’s analysis. Could you please explain what you mean by “key phrase based key” in this context?

8. #8 ShadowWolf

   key phrase

   28. Februar 2021

   Norbert:
   It is just like a regular keyword. ACA type K2 technically. The only real difference is there is at least 3 keywords and possibly a 4th very abbreviated word making it more of a phrase than just a key word. The letters are used as in a normal keyword as the one repeated letter is missing. There is also one clever letter substitution but it is something you have to see if you haven’t already. This is something that may remain a puzzle but I can speculate though it is probably a bit vulgar. I decided to just leave it alone. So instead of a keyword such as “smoking” there is a short phrase “can of wurms”. It is also an odd arrangement with some of the lesser used letters inserted as spaces between the words. So you end up with further mixing “canXofZwurms”. Yes I misspelled worms unless you are a D&D player, perhaps a fan of dragons or maybe Edward Elgar.

   If you are thinking like the false solution from Roberts, it is nothing like that insanity. I’m pretty sure nobody ever used a phrase for an entire substitution cipher key. You could just about do a paper on everything that is wrong with his solution. Even his symmetric symbol arrangement is not symmetric by any definition I use.

   My personal opinion of Elgar is not real good. Dora Penny had no chance of solving the cipher. The key itself was manipulated to be outside the textbook norm as we would know it and many would expect. Elgar wanted her to fail. Combined with what has been dubbed “Elgar speak” the cipher is virtually double encrypted. The key may also be an example of Elgar speak. In short, Elgar was horrible at creating crypto puzzles.

9. #9 Christof Rieber

   Wien

   28. Februar 2021

   I do not see any indication why the cipher should be fake. Instead, it even shows a rock solid monalphabetic frequency distribution with most likely J (from transcription above) representing the letter ‘E’ (12.64%).

   When it comes to vowel analysis, Sukhotin shows very clearly some letters to be vowels vs. others to be consonants. There is, however, some asymmetric distribution of those vowels, too. This may or may not be explainable (e.g. the sentence “This is why thy girl did not call a dog a rabbit” does not even contain one single letter ‘E’.

   Mostly, the problem with the cipher is that the words are not separated. A mono-alphabetic substitution is NOT ruled out, imo. What is unlikely, however, is that the directions of letters were set-up in groups, eg. ABC PON etc. according to the symbols’ clock type of diagram. They were rather mixed in a way that somebody indeed had required a 1:1 transcription key to it. This leads us to

   26^22 or 13,471,428,653,161,560,586,981,973,426,176

   different variations of how the letters can be placed mono-alphabetically – with only one of them to be correct.

   I think the cipher, rather confimed by Elgar’s hand notes as well as sayings (instead of indications for forgery), will be cracked in less than a year.

   Some ‘section’ I currently work on, to get a break (but not yet found):

   HRELIEVEEDWWEIGHG
   FIELDEKEEPSSEDTFT
   SPEAREWEEUTTERMSM
   LVENTEREEDMMETALA
   ..

   Still nonsense, I know, but not to the degree that one could say there wouldn’t be a solution in the future.

10. #10 Norbert

    1. März 2021

    @ShadowWolf
    “ACA type K2” doesn’t help me a lot. Let me explain what I mean. To my knowledge, there a two basic options to create a MASC according to a key phrase. Either you form the enciphering alphabet after the key, or the deciphering alphabet. Let us assume a key phrase “Edward Elgar”:
    
Option 1
deciphered ABCDEFGHIJ...
enciphered EDWARLGBCF...

    Option 2
enciphered ABCDEFGHIJ...
deciphered EDWARLGBCF...


    Both options usually assume that the cipher uses the same alphabet as the plaintext. But what if the cipher is composed of arbitrary symbols, like the Dorabella cipher? Option 1 can be ruled out then. Option 2 is still possible but you have to put the cipher symbols in a logical order. This is what my question was about. In which order do you put the Dorabella symbols to make your key phrase appear? And please don’t say that you put them in the order A, B, C, … of your transcript 😉

11. #11 Narga

    1. März 2021

    @Norbert:
    The American Cryptogram Association (ACA) describes four types of keyword “plans”:
    K1, K2, K3, and K4. They all have keyword(s)/keyphrase(s) plus an offset shift letter e.g. “R”, resulting in a rotation of the two alphabets wrt each other.

    Your Option 1 where the plaintext alphabet is normal, and the ciphertext alphabet contains the key is called K2. The other three types are:
    K1: The plaintext alphabet contains the key, and the ciphertext alphabet is normal:
    pt: poultryabcedfghilkmnqsvwxz
ct: RSTUVWXYZABCEDFGHIJKLMNOPQ
    K3: Both alphabets are keyed with the same key:
    pt: conquestabdfghijklmprvwxyz
ct: HIJKLMPRVWXYZCONQUESTABDFG
    K4: Both alphabets are keyed; each with a different word/phrase:
    pt: shoptalkbcdefgijmnqruvwxyz
ct: VWXYZJUPITERABCDFGHKLMNOQS

    That all reminds me a bit of the 6 Ohm’s laws I had to remember during my military service 🙂

12. #12 Norbert

    2. März 2021

    @Narga:

    reminds me a bit of the 6 Ohm’s laws

    To me, K1-K4 reminds rather of very high mountains 🙂

    Thanks for the clarification! Very interesting.
    But the point is and remains: all K’s assume that the ciphertext uses the same alphabet as the plaintext. How then can the Dorabella cipher be K2? At the most if you replace the cipher letters by their transcription, but then everything depends on how you transcribed.

    If one transcribes as usual the first occurring character with A, the second with B etc., then one can always claim the cipher to be K1 with a key phrase identical to the found plaintext …

13. #13 ShadowWolf

    Symbol Order

    8. März 2021

    The symbols are arranged in a clockwise rotation starting with the open side of the U shape facing right. From that position rotate the symbol 45 degrees clockwise. To verify you have it right, the U shape faces down in the 3rd spot, left in the 5th spot and up in the 7th spot.

    After you have all 8 rotations, the sequence is 3, 1, 2 so that the triple set is first, the single set is second and the double set is last. If you stack them in rows or columns, they are symmetrical top to bottom or left to right.

    I have already warned you that it isn’t a typical keyword arrangement though it does mostly follow the typical rules and no letter is repeated. An argument can be made that Elgar was trying to make a tough puzzle.

    From the clues already given, the double U shape with the open side facing up and left is E after you transcribe the letter key back to symbols. T is in an expected place for a keyword alphabet also a double U shape facing down. Then the H is the double U shape facing up. If you get the rest of the alphabet sorted out, you will see a key word alphabet with the non-standard features already noted. The key word/phrase covers the first two sets or 16 symbols. Which is actually only a very small clue for a letter that you would find anyway.

    I think I see the problem with the notation. Probably better if we ignore that. I let my fingers type faster than my brain on that part. Most substitution ciphers are K2 and at some point I forgot about what was actually happening. If I want to be really technical, it is a K4 because both sides are not strictly ordered but it might still be safe to call it a K1 because of the symmetry of the symbols.

14. #14 catherine chappell

    Heidelberg, Germany

    18. Juni 2022

    I have deciphered the note, it is double enciphered hence the difficulties with the frequency tables. The Idea that Dora could have forged such a note proves categorically that you have not read her book! I am about ready to publish my solution. It is in English! not gibberish.