A young man, who had disappeared from his home in California, sent an encrypted message from Israel to his parents. This cryptogram has been unsolved for over four decades. Can a reader decipher it?

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The cryptogram I am going to present today is mentioned in only source I am aware of – on the title page of the Jan-Feb 1976 edition of the magazine Cryptogram, published by the American Cryptogram Association (ACA).


The MLH cryptogram

Here are the four paragraphs from the Cryptogram describing this encrypted note:

About 2 years ago a young man left home. He had not been heard from until October, when his mother received the enciphered message traced above. It has been forwarded to us [the ACA] for help in reading it.

The envelope was typed neatly and correctly except for a lower case “a” in “Apt.” and “Avienda” or “Avenida” (California-Spanish ”Avenue”). In place of the return address there was the single word “Milestone”, typed, which the parents believe has something to do with the content, possibly indicating that he has “passed a milestone” in his life. The message was written in ball point pen on a strip of paper, torn or cut from a larger sheet (worksheet?). MLH are the mother’s initials. There is no hint as to why he wrote in cipher; he had not shown any interest in cryptography that they know of.

The author was born Nov. 19, 1954. He had been a programmer and electronic circuit designer. He was badly injured in an industrial accident, recovered, and was again injured in an auto accident in which two friends were killed. Prior to these accidents he had been interested in American history. As he recovered he became interested in parapsychology, religion, and astrology.

The only other trace of his wandering is the record of a check cashed last February in Paris. He seems to have disposed of his possessions, returning items to friends, etc. this message was sent from Israel be Air Mail.

And here’s the cryptogram:


To my knowlege this encrypted note has never been deciphered. Although it represents a note-worthy mystery with an interesting background story, this note has never received much attention in the crypto literature.


Many ideas but no solution

I published my first blog post about the MLH cryptogram last year in April (in German). Some readers posted interesting comments:

  • Richard SantaColoma wrote: “Parts of it remind me of a rebus. The ‘caret’ might be a ‘greater than’, with the circle/dot being an ‘eye’, for instance: ‘more than eye’? Then, the heart, with the ± signs on the sides of the heart meaning that they ‘more or less’ love ‘Poo, too’. A pet? Sibling? There are what look like headphones earlier, too… ‘listen’? It might also make sense to use a rebus, as why would the man otherwise expect his parents to know the cipher?”
  • Wolfgang Wilhelm noted: As the note was sent from Israel, it should be taken into account that it was written from right to left.
  • In another post Richard SantaColoma wrote: “Considering the man’s background in early computer languages, I looked over several of them. Many of the characters he used in his cipher can be found in these languages, such as the ‘delta’, ‘caret’, ‘plus/minus’, and more. Look at early ‘C’, ‘ALGOL68’, and APL languages, among a few. In some cases, these computer symbols map directly to IBM keyboard keys, such as in ALGOL68, in which the ‘Delta’ is the letter ‘H’ on the keyboard.”

Tobias Schrödel contacted the ACA and asked if anything new had been found out since 1976. Apparently, this was not the case.

Of course, there is also the possibility that the MLH cryptogram consists of meaningless symbols. Maybe the sender wanted to confuse his parents. However, this hypothesis is hard to prove.

Further reading: Tengri 137 has posted again


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Kommentare (13)

  1. #1 Rese
    24. Mai 2017

    Personal I think the the conclusion from Wolfgang Wilhelm is false.Consider the background as a programmer. Japanese Programmer don´t write code from top to bottom. If you get my point.
    The symbols itself remind me a lot of Unicode and I think best way to solve the puzzle could be by publishing it at Linux Magazine or similar platform.

  2. #2 tomtoo
    24. Mai 2017

    And the end it says tool. That could be a hint. mlh could be a tool.
    First you have to start mlh and redirect “>” the output to this filename..than something i dont know..than start mlh with option /e

  3. #3 tomtoo
    24. Mai 2017

    Oh my englisch sry. If mhl was a tool on the computer, than the msg was maybe for someone in the inner familie circle, that has computer knowledge. Brother ? Sister ?

  4. #4 Klaus Schmeh
    24. Mai 2017

    Bart Wenmeckers via Facebook:
    Most likely… how one would even transcribe this would be a challenge…

  5. #5 Thomas
    24. Mai 2017

    Transcribing this would be a challenge? I think not. But, provided that it is a substitution cipher, it is too short to draw conclusions from frequency and pattern analysis.

  6. #6 tomtoo
    24. Mai 2017

    With out the Computer and the tool on it , what sense should it make ?

  7. #7 Klaus Schmeh
    24. Mai 2017

    American Cryptogram Association via Facebook:
    Kinda looks like a short letter to me. Maybe starts with [dear] or [to] Mom. Then line 2 might end with [mommie] [period] then [I love you] Then signed XO [maybe another O?] as in XOX, hugs and kisses. No ideas on the rest of it. Or maybe none of this is on target.

  8. #8 tomtoo
    25. Mai 2017

    start could be: hug mom

  9. #9 Rese
    25. Mai 2017

    what sticks me is why would he address his mom like that? Maybe tomtoo is right and its a file/tool on his computer (he named after his mother)?

    I also would agree with Richard SantaColoma in Algorithmic language case (would go turing tarpit :) and with ACA that in the second line a period is mentioned.

  10. #10 Larry
    Not APL
    25. Mai 2017

    I have compared the available symbols to APL, a language I used to write in professionally. Too many of the symbols have no obvious (or even unobvious) APL analogs.

    It also strikes me that if this is some real communications means, there are something like “ligature” characters. These are either unique characters or characters that, for some reason, were written close together. Ligatures come mostly from printing, but they might also arise in calligraphy. Neither seems likely here.

    Unicode is pretty certainly not an issue. It was not invented until well after the ’70s.

  11. #11 Bruce Grainger
    Im old and not too swift.
    4. Juni 2017

    I do not think he would have sent a cryptogram in any language his parents didn’t speak or have the resources to translate. I would check his room at home out for the source figures as well as documentation. Depending on the age of the document I would also recommend looking through his room closely checking closets and wood trim boards . The ceilings in closets and floors a a trove when looking for clues. If his room at home hasn’t been touched i would go so far as to check under mattresses and loose floor boards. looking through books is also another way. if he is a computer geek the cds or what ever data storage unit he was using as well as old files.

  12. #12 Galen
    11. Oktober 2017

    Perhaps just a coincidence, but there’s a review on, by someone using MLH as their ID, claiming to have an address in Mt. Morris, IL, USA, of a book called “Cryptogram Puzzles”:

    The review says only, “Love this game.”

  13. #13 Galen
    Could it be a clever puzzle instead of a real-world story?
    11. Oktober 2017

    Has anyone ever asked a question like the following, about the MLH cryptogram:

    Is it possible that the person who originally wrote the text published in “Cryptogram” was merely creating a hidden puzzle of some kind, and as a “frame” for the puzzle, invented the story about the missing young man and his mother M.L.H.?

    (Lacking any of the surrounding context from that or other recent issues of the magazine, I don’t think we can be certain–though I admit this is probably a very long shot, at best.)

    If that were the case, I suppose we’d have to begin our search for clues by examining carefully the text in the full context in which it was published, perhaps searching the entire Jan-Feb 1976 issue of Cryptogram, or even a previous issue or two.

    Klaus, was the four paragraph section you posted an excerpt from a longer story, article, or letter?