Two months ago, US book author A.J. Jacobs showed me the encrypted journal of psychologist Abraham Maslow (1908-1970). My readers did a good job in analyzing this cryptogram. Now, A.J. asks for additional help.

Earlier this year, I met journalist and book author A. J. Jacobs in New York City.

A. J., who has an English Wikipedia entry and a German one, wrote a number of great books, three of which I have read so far: The Year of Living Biblically (German title: Die Bibel & ich), The Know-It-All (German title: Britannica & ich) and Thanks A Thousand.

Source: Schmeh

At the moment, A.J. is working on a book about puzzles. He plans to include crossword puzzles, the Rubik’s Cube, mathematical puzzles, jigsaw puzzles, mazes – and cryptographic challenges.

If you don’t want to spend money on a book, try A.J.’s 2010 article Will doing EVERYTHING my wife tells me turn me into the most perfect husband?.


Maslows encrypted journal

During our meeting in New York, A. J. showed me scans of an encrypted journal written by renowned U.S. psychologist Abraham Maslow (1908-1970). Here’s a page from it:

Source: Jacobs

For more scans, check my blog post from March 6, 2020. The blog readers Gerry and Erica published a few intereting comments on this cryptogram. Apparently, Maslow used several Caesar ciphers with different keys to encrypt some passages of his journal. However, most of the ciphertext is still unsolved.


A. J.’s Reddit post

Of course, A.J. would like to have the complete journal deciphered. So, he asked me if I could blog about it again, which I am doing now. In addition he published a post on Reddit. Here’s what A.J. wrote:


I’m in possession of the encrypted diary of pioneering psychology Abraham Maslow (inventor of the famed Maslow’s Hierarchy of Needs).

I got the pages from my friend Scott Barry Kaufman, a psychologist, who just wrote a great new book about Maslow called “Transcend.”

He gave me permission to put the encrypted pages here to see if anyone here can help crack the code.

The code also was written up a couple of weeks ago on the blog of Klaus Schmeh, and some commenters made a bit of progress.

One cryptographer in particular has been working on it, and making some really interesting insights. But we both decided it was best to try to get help.

I’m posting the diary pages (the first part of which are in plain English, the last part of which is encoded)

Can’t wait to see what you all find.

It would be great you, dear readers, could take another look at this encrypted journal. The encryption used by its author appears to be more complex than most other diary encryption systems I have seen so far. Nevertheless, I’m sure that this cryptogram can be broken. If you can help to solve this crypto mystery, please let me know.

Further reading: The encrypted diary of Ignaz Meyer


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Kommentare (5)

  1. #1 Gerry
    25. Mai 2020

    I think without more encrypted pages and more context it will be difficult to break Maslow’s code. Looking at the unusual long words I think he encrypted some letters with two letters and some with only one, sometimes having more than one substitution for a given letter.

  2. #2 Erica
    25. Mai 2020

    Interesting thought Gerry. At one point I was thinking this was in Latin, with the longer words, but the single letter words aren’t so common. I was thinking this was a date shift cipher, as a key of 8 seemed to explain replicated words (I am focusing on the third page btw in last Maslow post)

  3. #3 Erica
    25. Mai 2020

    What do you make of the word CDEFG in the above picture?

  4. #4 Magnus Ekhall
    25. Mai 2020

    Just a note:
    On the third page in the previous post the word “rpeom” occurs three times. Two out of these three times the word is “decorated” in exactly the same way: the “r” is circled and so on.
    I have a feeling that these decorations may actually be part of the cipher somehow.

  5. #5 Erica
    25. Mai 2020

    I had the opposite feeling seeing that rpeom was decorated differently, but thinking it was the same word. Notice there is an ASEOM as well.