StartseiteCipherbrain

How a crypto mystery from the Cold War was solved – or was it?

Von / 16. November 2016 / 7 Kommentare
Mehr

In the 1950s the Germans used a unique crypto device named “Violine”. I have always wondered what it was used for. In a book about espionage I found the likely answer.

Last Saturday I was in Duivendrecht near Amsterdam to attend an exhibition named Secret Communications 2. This exhibition took place in the Arthur Bauer Museum. It featured a collection of antique radio devices provided by the museum owner. The other half of the exhibition showcased encryption machines mainly provided by collectors Paul Reuvers and Marc Simons.

 

A great collection of encryption machines

Of course, the encryption machine part was the more interesting one for me. It contained two Siemens & Halske Geheimschreibers, a Typex, cipher telephones, a Fialka, Hagelin machines and much more. On the following pictures you can see a few Enigmas (left) and me talking with blog reader Karsten Hansky.

Amsterdam-Enigma-Hansky

Unfortunately, the Secret Communications 2 is limited to three days. The first exhibition day was Saturday, November 19. On November 19 and December 3 you will have to more chances to go there. I can only recommend to do so.

 

The Violine

At the exhibition, besides many interesting encryption machines, a copy of the book “Achtung Spione” was on display. This book (divided in two large volumes) contains much interesting information about espionage in the early Cold War. Cryptology only plays a minor role in it. However, one picture in the book immediately caught my attention. On page 252 of the second volume the following device is shown (for copyright reasons I have to use a different picture here, but it’s the same motif):

Violine

This device is a mechanical random number generator named “Violine” (German for “violin”). It is mentioned in my book Codeknacker gegen Codemacher. The Violine was used by the West German cipher authority in the 1950s. While it is clear that this device produces five digit random numbers, I have always been wondering what exactly it was used for.

In the afore-mentioned book I found the (likely) answer. Below the picture it says: “Violine […] for the simple use of the secure encryption algorithm ‘DEIN STAR’.”

In fact, the German secret service used a manual encryption algorithm named DEIN STAR in the 1950s. DEIN STAR is a variation of the One Time Pad. It was used by spies for encrypting short messages. It was secure and didn’t require treacherous crypto devices. How DEIN STAR works is explained on Jörg Drobick’s website. In the first step, the spy had to write down the following table (it is based on the password DEIN STAR):

\ 0 1 2 3 4 5 6 7 8 9
- D E I N     S T A R
4 B C F G H J L M N O
5 P Q U V W X Y Z . ,

The words DEIN STAR were chosen because they contain the eight most frequent letters of the German language (E, N, I, S, R, A, T, D). Using this table a text can be written in numbers with the most frequent letters requiring only one digit (the same concept was used for the VIC cipher). For example, the message I HAVE A DREAM is coded as follows: 24484 05318 09184 7.

The result of this first step is now added to a numerical key that needs to be as long as the coded message (each digit is added seperately without carry). For instance, if the key is 0940385805 we get the following result:

Cleartext (coded): 24484 05318 09184 7
Key:               09403 85805 23804 3
Ciphertext:        23887 80113 22988 0

Now the obvious question is: was the Violine used for creating keys for the DEIN STAR algorithm? I think this makes sense. If a reader has more information about this question, I would be interested to learn.

There is one other question I have been asking myself about the Violine for a while: why are the five chambers containing the number pegs not interconnected? Were the pegs devided into groups in order to get random sequences with certain properties? Maybe a reader knows more about this.

Further reading: German cipher machines in World War 2: A complete (?) list

Stichworte:
Mehr

Kommentare (7)

  1. #1 Thomas
    17. November 2016

    This is obviously a stone age method of creating random additives for one time pad use! But since in 1944/45 the US had broken the machine based random number system GEE (with five rotating number wheels) which was used by the German Foreign Office (https://books.google.de/books?id=lwKuAwAAQBAJ&pg=PT329) after WWII the return to a secure, even if not state of the art technology was reasonable.

  2. #2 Joe
    Berlin
    17. November 2016

    Die Frage die ich hatte nach dem Lesen der Beschreibung in dem Buch: Achtung Spione; hatte:
    Wie kommt der Empfänger der chiffrierten Nachricht zu den Zufallsfolgen?
    Ich Stufe das Gerät als Schlüsselgenerator ein der z. B. genutzt wird um Schlüsseleinstellungen – Initialisierung Vektor – vorzunehmen.

  3. #3 Klaus Schmeh
    17. November 2016

    @Joe:
    >Wie kommt der Empfänger der chiffrierten
    >Nachricht zu den Zufallsfolgen?
    Ich nehme an, jemand musste die Zahlen abschreiben.

  4. #4 BartW.
    18. November 2016

    Doesn’t make any difference to your question, but I don’t see how you get to your first coding result. I’d expect 24485 31809 1847, or 24448 53158 40918 47 if you encode the spaces as well. I cannot explain the ’40’ in your example.

  5. #5 Dirk Rijmenants
    Belgium
    18. November 2016

    Great idea, that violine, and pefectly secure. What a great find! Never saw this before but it’s an ingenious thing. Just shake the thing and let the numbers drop into rows of five digits and you have a standard 150 digits one time pad. Write down and give cupy to sender and receiver. The violine is probably either used to create true random keys on a small scale for real use or as a training tool. Its keys could be used for any one-time pad system, not necessarily in combination with the DEIN STAR table.

    This method is actually perfectly secure, as long as you shake enough. You could compare it to the wartime Soviet OTP production where analysis of actual key sheets showed a distinctive patern of left and right hand alternating to choose each digit. As with the violine, although no true randomness with perfect entropy, cryptanalyse of messages, encrypted with those hand types keys, remained impossible.

    The GEE peudo-random machine Thomas refers to is described in detail in the link below. It’s by the way incomprehensible that the German Foreigh Office used such a simple machine to generate keys for a system that would otherwise have been perfectly secure. Those messages were cracked because the keys were not one-time pads (which is unbreakable!) but in essence a simple stream cipher. Or how to screw up perfect security in the most disasterous way…

    https://www.cs.columbia.edu/~smb/doc/Cryptanalysis_of_GEE.pdf

    By the way, DEIN STAR is a mere text-to-plaincode conversion table (Umsetztabelle or Substitutionstabelle) and absolutely not a manual encryption system. I’m afraid the author of the book made an glitch. Its output is called plaincode to stress/warn that the text is only coded into another plain form and presents no security whatsoever. DEIN STAR is one of the many different mnemonics (like ANREIS, AT ONE SIR or SENORA) for various conversion tables of which the plaincode is always followed by encryption (as you correctly showed in example), not necessarily always one-time pad encryption by addition or subtraction, but also used in conjunction with less secure manual ciphers (transposition/substitution combinations)

    https://users.telenet.be/d.rijmenants/en/table.htm

  6. #6 Klaus Schmeh
    18. November 2016

    @BartW.
    I’m afraid you’re right. My encoding is wrong.

  7. #7 Frank Gnegel
    Frankfurt
    21. Dezember 2016

    In our colecvtion we have a printing device for printing sheets with blocks of five numbers. You can see it here:
    https://emp-web-09.zetcom.ch/eMP/eMuseumPlus?service=ExternalInterface&module=collection&objectId=311753&viewType=detailView

    We have been told that it is a “Differenzbildungsgerät” used by the German Abwehr to decipher the codes of British agents. But after reading the article about the GEE random number system I wonder wether the device in our collection may have been used to print the GEE pseudo-random code. What do you think?