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An encrypted postcard from India

Von / 5. November 2019 / 10 Kommentare
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Blog reader Karsten Hansky has provided me a nice encrypted postcard from 1954. Can a reader decipher it?

Encrypted postcards have always been a popular topic on this blog. Blog reader Karsten Hansky has now provided me another one.

Before I proceed, let me mention that my friends Paul Reuvers and Marc Simons from the Netherlands are going to co-host a crypto exhibition titled “Secret Communication” in Duivendrecht, NL. Check here for details. It will start on November 16, 2019. I plan to attend one week later, on November 23. Of course, I would be pleased to meet a few readers of this blog there.

Let me also mention that I will give a presentation at the Labortage in Bochum next Saturday (November 9th). This event is open to the public, a ticket costs 18 Euros.

The aforementioned postcard was sent from India to a certain Bent Hjort Nielsen living in Copenhagen, Denmark.

According to the two stamps, the card was sent in 1954, which makes it one of the most recent encrypted postcards I have ever seen. Most encrypted postcards I’m aware of were written between 1900 and 1930.

Let’s look at the text side:

The encryption system the sender applied might be a monoalphabetical substitution (MASC). Almost all encrypted postcards I have seen are enciphered this way. However, contrary to most encrypted cards, this one doesn’t indicate word boundaries, which makes breaking the message more difficult.

The alphabet used consists of ordinary letters and the digits 1, 4, 5, and 9. The digits only appear in the third-to-last line of the text. They form the sequence 1611954 (with exactly one letter between each two digits), which can be interpreted as a date: 11 January 1954.

The letter between the 1 and the 6 is an Æ, which appears in the Danish alphabet (the German equivalent of this letter is the Ä). This suggests that the plaintext is written in Danish.

The last line could be a signature. The letter combination EENN at the start of a word is very unusual. Provided that we are dealing with a MASC, this might render a crib.

Can a reader break this message?


Further reading: An encrypted postcard from the Isle of Wight

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Kommentare (10)

  1. #1 Norbert
    Berlin
    5. November 2019

    It seems not to be a MASC but a sort of two-row rail fence cipher. Interesting! I assume that the sequences “PLFM”/”LPFM” etc. have to be ignored (or they have another, maybe arranging function which I haven’t figured out yet). In the remaining text there are meaningful words to be found when skipping every second letter, like

    “TAK FOR” (thanks for) in the first line (in TeAnKiFnOgR) or
    “DARLING” in the fifth line (in DiAgRdLrIeNnG).

    Also the date appears in this way, as described by Klaus.
    Unfortunately, my Danish is not good enough …

  2. #2 Gerry
    5. November 2019

    Norbert, you are right, but I think the “TAK FOR” is maybe misleading, as all the other words start right after the PLFM/LPFM/… delimiter. So the PLFM delimit words, resulting in the danish plaintext:
    meningen er god nok vi hilser dig hjerteligst darling bent bror söster far mor 1611954 og vi hilser dig igen
    which translates to:
    meaning is good enough we salute you most heartily darling bent brother sister father mother 16.1.1954 and we salute you again

  3. #3 Gerry
    5. November 2019

    🙂 translation by google translate

  4. #4 Thomas
    5. November 2019

    There is a second message, starting “Tak for kortet” (Thanks for the card).

  5. #5 Christof Rieber
    Wien
    6. November 2019

    Should be done with this one:

    Use 4-letter combinations of PLFM letters as separator. The rest will select into every second letter, representing Danish vocabulary.

    OPINION IS GOOD ENOUGH. WE WELCOME YOU CORDIALLY DEAR. OBEISANCE. BROTHER SISTER FATHER MOTHER. 1st.1.1954. AND WE. HIEDI. SHE AGAIN.

    PLFM MTEANKIFNOGREKN – MENINGEN (OPINION)
    LPFM
    EOR – ER (IS)
    PFLM
    GROTD – GOD (GOOD)
    FPLM
    NEOTK – NOK (ENOUGH)
    PLFM
    VJI – VI (WE)
    PLFM
    HEIGLRSIENR – HILSER (WELCOME)
    PFLM
    DTIEG – DIG (YOU)
    FPLM
    HOJUEERRTEENLDIEGJSLT – HJERTELIGST (CORDIALLY)
    LPFM
    DIAGRDLRIENNG – DARLING (DEAR)
    FLPM
    BGEVNIT – BENT (BOW/OBEISANCE)
    PLFM
    BSRAOVRN – BROR (BROTHER)
    LFPM
    SEÖRSDTIEGR – SÖSTER (SISTER)
    LPFM
    FOAGR – FAR (FATHER)
    PLFM
    MGOLR – MOR (MOTHER)
    LFPM
    1ÆGD1E1R9O5S4 – 1.1.1954
    FLPM
    OTG – OG (AND)
    PLFM
    VIIL – VI (WE)
    PFLM
    HLISESDEIR – HIEDI (NAME)
    LPFM
    DGIIG – DIG (SHE)
    FPLM
    IGGEENN – IGEN (AGAIN)
    PLFM

    Remaining letters:
    takforkortetjegrinteouerendejligdrengvisavnerdigogglÆgdorstillssergigen

    Because of PLFM at start and beginning of the cipher, I thought it could be like telegram style ‘stop…text…stop…’ etc., which finally lead to the solution.

    Best regards

  6. #6 Christof Rieber
    Wien
    6. November 2019

    Rest might read similar to this (my Danish is not good enough to separate the words correctly, I guess). But there is a second message, indeed, with the rest of the letters:

    TAK FOR KORTET. JE GRINT…eouer ende jlig drengvisavn erdig og glÆg dorstillssergigen

    THANKS FOR CARD. ÝOUR LAUGH AND END YOUR SOLEMN VIGIL IN FRONT OF THE HOUSE DOOR

    Best regards

  7. #7 Christof Rieber
    Wien
    6. November 2019

    Small correction regarding BENT (BOW/OBEISANCE). The recipient of the postcard’s name was BENT, so the Danish word BENT is actually used as a name here (same spelling).

  8. #8 Christof Rieber
    Wien
    6. November 2019

    Date could indeed be 16.1.1954 instead of 1.1.1954.

    The completion of the remaining letters:

    tak for kortet je(g) grinte over en dejlig dreng, vi savner dig og ‘glÆ dorst ills sergigen’.

    Thanks for card. I smile over a wonderful boy, we miss you and ‘happy thirst sickens seargant’.

    (with ‘glÆ dorst ills sergigen’ most likely a regional cheers saying)

  9. #9 Klaus Schmeh
    7. November 2019

    @Norbert, Thomas, Gerry, Christof:
    Thanks and congratulations on solving this cryptogram.

  10. #10 BREAKER
    10. November 2019

    This is the same use of filler that is seen in the Ricky McCormick Cipher that the FBI is trying to solve.

    So far I removed the matching pairs of filler and it is speaking like a novel.

    Looks like someone had access to tons of ciphers and used this card as a tool with a key.

    Working on the second letter selections counting off, and might also be using a swap of text from one letter to the other …the card is a template that was used in this case, it appears.

    Check it out for yourself.