Today I am going to introduce two encrypted diaries. Only one of these is solved. Can a reader decipher the other one?

Encrypted diaries are an interesting topic for crypto history enthusiasts. My encrypted book list meanwhile contains about 25 diaries written completely or partially in a cipher. As diary authors usually avoid complicated encryption methods, almost all of these documents have been deciphered. In addition to the diaries on my list, there are a few more that only contain small pieces of encrypted content (like the journal of Czech poet Karel Hynek Mácha).

When I recently googled for encrypted diaries, I encountered two specimen I hadn’t known before. I included them as numbers 00090 and 00091 in my encrypted book list.


Clara’s diary

Encrypted book #00090 on my list is a diary kept by a person named Clara (the surname is not known to me). It is described in an article written by medicist John Essex. Essex’ article depicts two excerpts from the diary; here is the first one:


Here is the second excerpt from Clara’s diary:


As can be seen, Clara used a variant of the pigpen cipher to encrypt passages of her journal entries. According to John Essex, this cipher has been broken, which is not surprising, as pigpen codes are easy to decipher for an experienced codebreaker. Essex mentions that Clara used SHIT as a password to create the pigpen table. However, he doesn’t explained exactly how this worked. Can a reader find out the details of Clara’s pigpen table and decrypt the enciphered passages shown above?


manic_fuzz’ diary

Encrypted book #00091, which is also a diary, appears to be a lot more difficult to break. It is mentioned in a British online discussion forum named The Student Room. A poster named manic_fuzz reports that in his youth he kept an encrypted diary. Here’s a scan of a double page he provides (sorry for the bad quality):


manic_fuzz writes that he doesn’t understand his own writing any more (but he still has a key, so he could decipher it, if it should be necessary). Can a reader break this encryption? manic_fuzz writes: “Most of the symbols represent letters, although some represent pairs of letters or whole words which usually throws people off.”

Of course, I assume that manic_fuzz has taken into account that people will try to break his encryption. Nevertheless, if you can break the cipher, please post the cleartext only if you are sure that publishing it does not offend the diary author.

Further reading: Who can solve this encrypted diary entry?


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Kommentare (8)

  1. #1 David Allen Wilson
    27. April 2018

    On “Diary-1”, it says “Momma H. said, “Huh! Guess…” and there’s a four-letter contraction ending in ” ‘t “. That is going to narrow it down to a few words, like “don’t, won’t, can’t, isn’t”, etc.

    The first two letters of this contraction form a two-letter word at the end of that sentence; so that limits it to something like “is” or “do”; and the four-letter contraction is probably therefore “isn’t” or “don’t”.

  2. #2 David Allen Wilson
    27. April 2018

    Based on that theory, I make three grids:

    . .. …
    # # #

    and I draw out my two hypotheses, one with “Isn’t”, and one with “don’t”. It becomes clear that “Isn’t” is probably the correct one — because the alphabet can be written in the three grids:

    . .. …

    Now you have the key for Diary-1

  3. #3 m
    28. April 2018

    Regarding ‘SHIT is the key’, to save others the trouble of clicking through to the Essex article: shit was the guessed plain text word which allowed Essex to reconstruct the tables (like David Allen Wilson used ‘isn’t’).

  4. #4 Marc
    29. April 2018

    ABC (one point)

    JKL (two points)

    STU (three points)

    First sentence : When are you going to get marrried ?

  5. #5 Marc
    29. April 2018

    sorry, i didn’t notice comment #2

  6. #6 David Allen Wilson
    30. April 2018

    It’s OK 🙂
    Is there a better scan of the other diary (Diary-Manic-Fuzz.png)?
    It’s kind of an awful quality scan and chopped off on one side.

  7. #7 Klaus Schmeh
    2. Mai 2018

    @Marc, David, m:
    Thanks, this makes sense.

    >Is there a better scan of the other diary
    I’m afraid, there is no better scan.

  8. #8 m
    15. Mai 2018

    Manic Fuzz Diary:

    With help from the AABA pattern at the beginning of line 3, right side, I got most of the blue part, which starts `then my friends started saying’ (the P-shaped symbols are `ed’ and `ing’). You can work out the rest yourselves ^^, but the whole words remain unclear with that little text.

    Reads like they were really young when they wrote it.