A. J. Jacobs, a successful US author and journalist, has provided me scans of an encrypted journal written by a renowned psychologist. Can a reader break it?

Recently, I had the pleasure to spend a few days in New York City. I visited the two encrypted tombstones in southern Manhatten – check my Cryptologic Travel Guide to see where exactly they are located – and took a walk over Manhattan Bridge to DUMBO (Down under Manhattan Bridge Passover), a neighborhood in northern Brooklyn. The wheather was sunny, which proved ideal to take pictures such as the following (it shows the more southern of the two said tombstones).

Source: Schmeh

A. J. Jacobs

One of the highlights of my stay was a meeting with journalist and book author A. J. Jacobs.

Source: Schmeh

A. J. has an English Wikipedia entry, a German one, and a website. Before we met, I read his book The Year of Living Biblically (German title: Die Bibel & ich) and I liked it very much. Meanwhile I have almost finished another book of his writing, The Know-It-All (German title: Britannica & ich), while still another one, Thanks A Thousand is on my bucket list.

I particularly like A. J.’s way of writing, which connects his personal life (including his wife Julie) with the actual topic he covers. As a typical example, I recommend his 2010 article Will doing EVERYTHING my wife tells me turn me into the most perfect husband?, in which Julie plays a major role.

The main reason why A. J. and I met is that he is working on a book about puzzles. Among other things, he intends to cover crossword puzzles, the Rubik’s Cube, mathematical puzzles (as known from Martin Gardner’s publications), jigsaw puzzles, and mazes. And then he plans to include a chapter about cryptographic challenges. To learn more about this topic, he interviewed me about Kryptos, the Voynich Manuscript, modern encryption and a few other crypto-related things. I hope and trust that the information I provided him was helpful.

In his books, A. J. describes encounters with people of all kinds, including Mensa members, quiz champions, creationists, Jehova’s Witnesses, TV hosts, encyclopaedia enthusiasts, and strange family members. I wouldn’t mind if he also covered the meeting with me in his next work – though I know that his descriptions of the persons he meets is not always favorable.

Of course, A. J. would never write a book that does no more than introduce a few kinds of puzzles in a systematic way. Instead, he follows his usual way of telling stories about himself interacting with the actual topic, which is puzzles in this case. Especially, he plans to try his luck on solving a few particularly hard puzzles himself, even if he’s almost certainly bound to fail. Meanwhile knowing A. J.’s writing style, I’m sure that reading about his (probably unsuccessful) attempts to decipher Kryptos (K4) or the Voynich Manuscript will be very entertaining.


Maslows encrypted journal

Meeting A. J. Jacobs was an interesting experience for me not only because of the many thoughts and ideas we exchanged, but also because A. J. showed me an unsolved cryptogram a scientist has forwarded to him. It’s an encrypted journal written by renowned U.S. psychologist Abraham Maslow (1908-1970).

The first two pages of this document are entirely written in the clear:

Source: Jacobs

Source: Jacobs

The next three pages contain encrypted text:


Source: Jacobs


Source: Jacobs


Source: Jacobs

As mentioned many times on this blog, virtually all encrypted diaries and journals known in the crypto community have been deciphered. This is because diary authors tend to use simple ciphers that allow for speedy encryption, but are not necessarily secure. The cipher we are dealing with here is pobably not an exception. My guess is that these paragraphs are encrypted in a simple substitution (MASC). Frequency analysis and/or word guessing should lead to the solution.

Can a reader decipher Maslow’s journal? A. J. and I are looking forward to your comments.

Further reading: The encrypted diary of Ignaz Meyer

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Kommentare (10)

  1. #1 Gerry
    6. März 2020

    On page 2 with cleartext Maslow writes: “I’ve determined to make my code simpler”. And indeed, for the Confidential part at the end of this page he uses ROT 1, giving “this is my new code.” He finishes the page with the cleartext “It is much simpler”, but unfortunately for the encrypted pages he didn’t use ROT.

  2. #2 Gerry
    6. März 2020

    On page 1 with cleartext the pencil annotation “1-2-3” lead me to the solution of the Confidential part there: it is ROT 1-2-3-1 1-2-3-1 and so on, ciphertext “h jdwf pruikph uq zsjvh” becomes “i have nothing to write”.

  3. #3 A.J. Jacobs
    New York
    6. März 2020

    Thank you Klaus! As you know, I’m a big fan of your work and blog. And thank you Gerry! That’s amazing (and fast!) Were you able to decrypt the rest of the ciphertext?

  4. #4 A.J. Jacobs
    New York
    6. März 2020

    Also, maybe I’m wrong, but there seem to be two errors in his translation.
    Namely, the first letter of the code (H) should be (G)
    And the (P) in KPH should be a Q.
    Otherwise the pattern would be.
    +1 -2 -3 -1 -1 -2 -3 -1 -1 -2 -2 -1 -1 -2 -3 -1 -1 -2 -3
    Let me know if you got the same thing. Thanks!

  5. #5 Gerry
    7. März 2020

    A.J., you are right with KQH, and the first letter is +1. For a perfect -1 code the first letter should be J.

  6. #6 Gerry
    7. März 2020

    A.J., do you have more diary pages with pencil annotations (like “1-2-3” on page A and “mcnogse” on page #2, both bottom right), as they seem to be the clues to solving the ciphers?

  7. #7 A.J. Jacobs
    New York
    9. März 2020

    Hi Gerry — I wish I did! Those are all the pages I have. Any luck with the ciphers? I tried for awhile and haven’t made much progress. Or any progress.

  8. #8 Erica
    10. März 2020

    Here are some of my thoughts after studying these pages. Thank you for sharing!

    Page 1
    The first letter looks like a script J, which would be correct ciphertext. I have provided my transcript

    Note: 1-2-3 (in pencil)

    Page 2

    S G H R H R L X M D V B N C D
    T H I S I S M Y N E W C O D E

    Note: -1 after (in pencil)
    I’ve forgotten the c(ode?)
    FEB. 25

    What is Punk show? Prink?

    Page 3 (#1)

    -No time to transcribe yet.
    -Different pens/ink, suggests written over a long period of time.
    -Plaintext a clue that this is in fact a list of movies?
    -Long words, maybe surnames of actors?

    -Reoccurring words: ARS, BU and T
    -SIMILAR words next to each other: VSVESGLO ABACESGLO
    -Odd word: CDEFG
    -Diamond character occurs twice

    Page 4 (#2)


    -LMHQA occurs many times. Symbols seem to bear no use other that to superficially complicate visually.
    -Similar words: AMACESGMP & ORACESGMZ

    Note: j mcnoqse (in pencil)

    Page 5 (#3)

    Here is a transcription:

    Y rpeom ap slsgemjad rpeom goa k alulkj whemkm stkiuado in ojwtvesgll “thbkf”.
    Rpeom y hkguuaxa orpoestd iniaqjemfys ap k pyleedw.
    Aseom oj meguuamsro kecimaku ap lkesal preiqmo sulimsgrkj.

    -RPEOM (occurs 3 times) & ASEOM are similar.
    -Y & K could be A & I (shift of +2 and -2)

  9. #9 A.J. Jacobs
    New York
    13. März 2020

    Thank you Erica for all that work!
    Let me know if you make any more progress. I’d love to help. I’m not a deciphering expert, but I can try anything. I can also do busywork.
    Just let me know. And my email, by the way, is ajjacobs1@gmail.com Thanks!

  10. #10 Erica
    15. April 2020