Two years ago a detectorist found an encrypted note hidden in a WW2 bullet in central Italy. Despite many tries this cryptogram is still unsolved.

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In January 2015 the news portal SPLOID reported on an interesting discovery. An italian detectorist had found a small piece of paper hidden in a German bullet from World War II. The finding place was located in Southern Tuscany. This piece of paper bore an encrypted message.


A hidden and encrypted message

We deal here with a secret message that is protected with both steganography (data hiding) and cryptography (data encryption). According to the SPLOID article it was common practice among WW2 soldiers to hide notes in empty bullets, but usually these notes were not encrypted. Here’s a scan of the message (I call it “bullet cryptogram”):


The message is dated 8/13/44. It probably stems from an allied army, which drove the German occupators from Tuscany in 1944. Here’s a transcription:


The first (QM) and the last line (605YZ/FF) probably contain some meta information. The main part of the message has 44 letters.


An unsolved cryptogram

According to the SPLOID article, a forum poster suggested the following decryption:

The five letter codes read as follows, from left to right, top to bottom:

The final code at the bottom is a phrase:

This means that German soldiers were throwing grenades with their safety pins on and the allied soldiers threw them back with their safety pins removed. But were the Germans really so stupid? And why would a soldier write down such a message, encrypt it and hide it in a bullet? In my view this doesn’t make sense. In addition, the poster doesn’t tell how the decryption works. For these reasons, I consider this cryptogram still unsolved.

When I wrote a blog post about this story two years ago (in German), I received many comments. However, nobody came up with a plausible solution.


Field ciphers

My guess is that this message was encrypted with a British or American field cipher. A field cipher is an encryption method that can be used by hand or with a simple device. Cipher machines like the German Enigma or the British Typex are not considered field ciphers as they are too heavy for carrying them around and not very robust. A common British field cipher was the Slidex:


However, Slidex ciphertexts contain both letters and digits, while the bullet cryptogram consists only of letters. There must have been dozens of other British field ciphers in WW2, but there is surprisingly little literature about this topic.

The most popular US field cipher of the time was the M-209, a small and robust encryption machine. As I will show in one of my next blog posts, the M-209 was far from unbreakable.


Other US field ciphers, like the M-94 or the M-138 were already outdated in 1944, but were still used as backup devices.

The bullet cryptogram is an unsolved crypto mystery. Can a reader solve it?

Further reading: An unusual cipher from a WW2 intelligence officer


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Kommentare (9)

  1. #1 Rich SantaColoma
    4. März 2017

    “According to the SPLOID article, a forum poster suggested the following decryption:

    “The five letter codes read as follows, from left to right, top to bottom:

    I think the (modern) person who suggested this was probably joking. I would guess they saw “Tuscany”, and didn’t understand who was fighting in the area at the time. Jokes making fun of the ability and prowess of Italian army were common in WWII, and even continued to be heard in my childhood in the 1960’s, probably told by fathers and grandfathers, and repeated in schoolyards. It sounds like one of those jokes, although I never heard that one.

    But if it did turn out to be the correct decryption, it would still almost certainly be a joke, not a reflection on what was really happening. And in that case I doubt it would warrent being hidden in a bullet.

  2. #2 Jokep
    6. März 2017

    Short question regarding the term “bullet” – was the text really inside of a projectile? Or was it inside of an empty cartridge?

    bullet = Projektil
    cartridge = Patrone

  3. #3 Bernhard Gruber
    6. März 2017
  4. #4 Bernhard Gruber
    6. März 2017

    I can imagine that the number ‘605’ at the end is not encrypted. Maybe ‘605YZ’ means ‘605th’.
    The 605th Ordnance Ammunition Company was in Tuscany in 1944 as part of the 87th Ordnance Battalion Headquarters and Headquarters Detachment. ‘FF’ means ‘HH’ for Headquarters and Headquartes Detachment?

  5. #5 Max Baertl
    6. März 2017

    Maybe the “QM” in the upper left corner means “Quartermaster”

  6. #6 anderer Michael
    7. März 2017

    Eine Patrone ( cartridge) besteht aus der Hülse (cylindrical casing, case), dem Geschoss in der Hülse(bullet) und der Pulverladung/ Anzündhütchen (gunpowder/primer).
    Also die Nachricht kann nicht in einem Geschoss /Bullet gewesen sein.
    Im Orginaltext steht: A bullet inverted into its case.
    Jokep du hast recht. Irgendjemand hat eine Patrone genommen, das Geschoss rausgenommen, die Pulverladung entfernt, die Nachricht in die Hülse gesteckt und das Geschoss umgekehrt auf die Hülse gesteckt , um sie zu verschließen. Projektil und Geschoss sind in dem Fall synonym. Patrone ist der Überbegriff für alle Komponenten zusammengebaut.

  7. #7 anderer Michael
    7. März 2017

    Ich sehe gerade, dass Herr Gruber bereits darauf hingewiesen hat.
    Künftig werde ich versuchen , meine Kommentare in Englisch zu schreiben und vorsichtshalber die deutsche Version, weil meine Englischkenntnisse nicht gut sind.

  8. #8 kud gt
    13. März 2017

    My read is at least one letter (I) more in the fourth line, before the “RSUA”, perhaps another more (U) after the same lettergroup. (seen in the orig. pic)

    QM 8/13/44

    Could QM be a shorten toponym?
    Could the month/day be the coefficients for a affine or shift cipher?
    “FF” stands for name or rank?

  9. #9 Mark Manning
    3. Januar 2020

    First to anderer Michael – don’t worry about it. Just use Google’s Translate – comes out fine in any language then. 🙂

    Second: All cartridges have an ID number do they not? Maybe that was used in doing the cypher. Then, each cypher would be unqiue would it not?

    I’m just passing through. Haven’t done any cypher work yet – but thinking of working on a PHP script to work on cyphers. 🙂