An old newspaper article mentions a Czech cipher machine from the 1920s. Can a reader find out more about this device?

Deutsche Version des Artikels (Test)

The decade after the First World War is an interesting one for crypto historians. After almost all (manual) encryption systems used in during the war had failed, numerous engineers now developed machines for encryption. Their goal was to create devices that were easier to operate and more secure than the paper-and pencil systems that were employed before.


Cipher machines from the 1920s

Although the concept of machine-based encryption proved successful, the first decade was hard. Many early cipher machine designs failed or only made it to practical use only after substantial redesigns.

For instance, the early models of the Enigma proved impractical. The Kryha encryption machine

Source: Hütter

… was neither secure nor user-friendly. The Zschweigert cryptograph

Source: Patent

… was flawed. The machines designed by Edward Hebern

Source: Smithsonian Institution

… belonged to the best of the 1920s but were still not successful. The cipher pantograph

Source: Patent

… by Gilbert Vernam wasn’t a top seller, either.


The Panmillion cryptograph

Slovak crypto history expert Jozef Krajčovič recently found a description of another encryption machine from this interesting time: the Panmillion cryptograph. According to a blog post Jozef wrote, this device was invented by a Czech military captain named Josef Sieber. Sieber also invented a cipher pantograph, probably similar to the one mentioned above, but this device is not relevant here.

The Panmillion cryptograph is mentioned in a 1920s newspaper article (Narodni listy, No. 69, vol. 65, p.10) Jozef introduces on his blog. Jerry McCarthy has thankfully provided me the follwing translation of it (check here for an annotated version):

Last May we reported on the remarkable invention of Czechoslovakia Captain Josef Sieber’s “deformation pantograph”, the production of which has now been taken over by the Prague company Srb a Štys. Today we can report on a new invention by the same officer, an encryption and decryption machine which the inventor called “Panmilion” and which not only stands out with the best known design of these combined machines, but surpasses them in its relative simplicity and ease of use.

Currently, “Enigma”, about which we once reported, is considered the most perfect encryption machine. That machine is similar to a normal typewriter, with a three-row keyboard and a total of 26 keys. The alphabet of this machine has 52 international characters.

The machine can be equipped with 24 thousand million different keys. The function of the machine is such that automatically, when enciphering, instead of a written letter, the machine itself writes another letter, when repeating the same letter it replaces it again with another letter.

The machine must be connected to a 120-220V normal power line or it can be powered by a battery pack of the same power, or it requires a special generator to produce the necessary electricity. Typing is similar to ordinary typing.

We simply type the message using the machine, and it itself writes it in cipher; when decrypting, the letter of the encrypted message is typed, and here, if the machine is set to the same key as the machine with which the message was encrypted, the machine writes the original text.

Captain Sieber’s encryption machine can be connected to any ordinary typewriter; typing on it is the same as typewriters. Machine size is 360x360x140 mm, its weight is 8 kg. An electric supply of 4 – 6 V is sufficient to drive it. The basic number of keys is approximately 400,000 sextillion.

The alphabet of the machine contains 35 characters. There are another 531,441 options for each key, ie additional keys. Each letter has a special key, arbitrarily controllable and changeable even during the process of writing one message; the key of one letter is in no way in relation to thekey of another letter.

The machine is equipped with two methods of encryption, either in alphabetical characters (letters) or in numbers. The special equipment of the machine enables perfect writing in all languages where Latin is used.

The machine converts the special marks of a language into the international Hughes alphabet, and when decrypting, the re-emerging text automatically provides these marks. The machine can be brought into three positions, from telling special marks and letters of all national languages. The machine can be manufactured in 74,000 different constructions so different from each other that even with a known key, it is not possible to decrypt a message written by a differently constructed.

As a result, the machine can be used simultaneously in many institutions and in many states without the risk that even if the key is revealed, the owner of another construction could decrypt the messages not intended for him.

The internal connection would be the secret of the owner of the machine and could be easily changed at will at any time. Due to the sufficient strength of the 4-6 Volt supply, the machine can also be used for service in military formations in the field in the event of mobilization, as two small dry batteries are always easy to obtain and renew.

Attaching the machine to an ordinary typewriter does not preclude the typewriter from typing; it is possible to type on the typewriter even if the Panmilion encryption machine is connected. The price of a machine is a good half less than the price of other solid encryption machines.

According to our detailed information, we can confirm that the Panmilion encryption machine is a surprising work of a serious inventor, and with its construction it achieves primacy in this field today. It will be interesting to see whether the inventor will find an enterprising manufacturer in this country or whether he will have to look for it, to our economic damage, abroad.

The Panmilion cryptograph allegedly could be used with “any ordinary typewriter”. I assume that this is not true and that only an electric typewriter was suited. In addition, the article mentions the Hughes alphabet, which probably means that the device could be connected to a Hughes telegraph …

Source: Wikimedia Commons

…, a popular telegraphy machine of the time.

According to Jozef, the Panmilion cryptograph might be have been a rotor machine similar to the Enigma. Does a reader know more about this device? If so, please let me know.

Further reading: Edward Hebern’s mysterious vacuum tube cryptograph


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Kommentare (9)

  1. #1 Richard SantaColoma
    6. November 2020

    Some thoughts form the description:

    1- I do think that this was intended to be used with a manual, not electric, typewriter. I saw this because of the part that states, “Due to the sufficient strength of the 4-6 Volt supply, the machine can also be used for service in military formations in the field in the event of mobilization, as two small dry batteries are always easy to obtain and renew.”

    2- From the size, 360x360x140mm (about 14x14x5.5 inches), I’m going to guess this was meant to sit UNDER a typewriter, not on top. So perhaps the typewriter sat over this device.

    3- I also do not think that it was intended to be next to a typewriter, because it seems it had to have some sort of mechanical, or possibly optical, connection to the typewriter.

    4- The device is VERY heavy at 8kg. Since it is electric, too, I would suspect that it incorporates one or more transformers, for some purpose or another, or other devices such as a motor or motors. If so, perhaps this was a printer, too.

    5- Putting it all together, if the above are correct, I would guess that this machine took advantage of the movement of the keys of a typewriter… the mechanical movement. Since the bottom of almost all typewriters is open, this means the arms attached to the keys is accessible. So my guess is that the device connected TO those arms. Perhaps with wire rods? That is, however this device was meant to operate, the input was through the pressing of the keys of the mechanical typewriter. These pushes then activated that function of that part of the cipher machine, which would then “do its magic”.

    I think it follows that this is the basic means of inputting the plain text letter choices, as it then follows that, as claimed, “Attaching the machine to an ordinary typewriter does not preclude the typewriter from typing; it is possible to type on the typewriter even if the Panmilion encryption machine is connected.”

    The operator would, yes, use the typewriter as an normal, even typing the plain text on paper if they so chose. But then the machine underneath would be reading the key presses, and converting that to cipher text… and outputting it electronically (in a format the Hughes could use?), and/or typing the cipher text on paper.

    It also follows that a reciever of the cipher text would simply have to use the same setup, with the same settings, and type normally on THEIR typewriter, with the cipher text being automatically converted below, on Mr. Seiber’s machine.

    Just food for thought. I could not find any but one patent, a German one, for this man… if the same man… from 1942. But not related to cipher machines.

  2. #2 Richard SantaColoma
    6. November 2020

    I am going to take one more (highly speculative) leap here, and suggest the possibility that the key presses on the typewriter, after being transferred by rod (flat or round) activated either switches, or solenoids within the cipher machine below.

    But because again, that weight, I would suspect individual coils, and copper coils are heavy. Even if small, the necessary 35 (stated number of characters) solenoids would end up making the unit heavy.

    So perhaps the device used coil switches, like electromagnetic, rather than mechanical means to read the key presses. This would make sense, as mechanical switches would probably always add interference with the operation of the typewriter; while sensing the input rod passing a coil would be minimal.

    Such a setup would then transmit the information about the pressed key electrically to the cipher portion of the device… as an Enigma does, through rotor switching?

    There would also then be a solenoid to advance a series of rotors. Each press would advance the rotors, electrically, and then send the information as to which plain text character had been pressed, just after, through those rotors.

    Basically, if correct, the system has a drawback… and one which, if you think about it, undermines the practicality however the device worked: One is buying a device that is, yes, half the cost of other cipher machines, but really only using the typewriter the user provides, for its keyboard. So then, why not just include a keyboard WITH the machine?

    No matter how this worked, I can see no practical advantage, other than a copy of your plain text on the above typewriter, to make any machine attach to an existing typewriter.

  3. #3 Jerry McCarthy
    England, Europa...
    6. November 2020


  4. #4 schorsch
    6. November 2020

    The fact, that a text encrypted with the Panmilion will never be decryptable might have been a slight disadvantage in the inventors eyes – but surely a big obstacle when it comes to marketing.

    If ‘Each letter has a special key, arbitrarily controllable’, then the result of the encryption of any letter will be indistinguishable from the encrypted equivalent of any other letter. There is only one way to distinguish different letters encrypted in this way: The encrypted text must carry the information, which of the ‘531,441’ different keys per letter has been used.

    But this will not only fatally weaken the encryption, but blow up the text to at least four letters per any single letter to encrypt.

    Klaus: You guess that ‘only an electric typewriter was suited’. While electric typewriters were invented before the big war, I seriously doubt, that in 1920 you will find any such device in the whole former K&K monarchy.

  5. #5 Gerd
    6. November 2020

    As the article talks about an “invention” I wonder if anyone here knows how to search the database of the Czech patent office. Maybe Jozef already tried?

  6. #6 Jerry McCarthy
    England, Europa...
    7. November 2020

    @schorsch I suspect that methods similar to Enigma would be used, such as a pre-shared coding sheet. The multiple keys for each letter is not so different from the Steckerbrett.

  7. #7 Jan Pulkrábek
    Bystřice nad Pernštejnem, Czech Republic
    7. November 2020

    Wikipedia article about Srb a Štys company (only in Czech):

  8. #8 Eugen Antal
    7. November 2020

    Klaus, I have a few notes:

    Information about the Panmillion cipher machine was first time published, in Dustojnicke listy (officers’ letters in English), No. 7, vol. 5 (13.2.1925) just one month before publishing in Narodni listy (national letters in English), No. 69, vol. 65 (11.3.1925). In the first article published in Dustojnicke listy, the name of the machine is with double l, and there are some additional details (e.g. the Panmillion’s price is estimated to “25.000 – 30.000 Kč”.).

    As I already mentioned in my comment in your post “The International Olympiad in Cryptography and other crypto news”, my guess is that this machine was not really used in the army, maybe the construction of this machine was reused in another machine design.

    About the “connection to a typewriter” – I imagine this as “The Kryha Elektric” (you wrote about in “A list of Kryha encryption machines”). As far as I know, this version of Kryha is also connected to a typewriter that serves as an input. But this is only my guess.

    “Sieber also invented a cipher pantograph” – this is not correct. He invented a deformation pantograph that has nothing common with ciphers and cryptography (see examples on the last page of the patent, see This pantograph was patented by the company Srb a Štys in 28.04.1924 (patent no. 26713).

    @Richard SantaColoma
    “The device is VERY heavy at 8kg.” – If you compare it with 50kg of Enigma A from 1923, it’s not too much …

    “I wonder if anyone here knows how to search the database of the Czech patent office” – I’ve already checked the patents a long time ago :-). Unfortunately, I was unable to find any patent of a cipher machine designed in Czechoslovakia (at least available in the public database). On the other hand, I’ve found 16 patents related to cryptography in the Czech patent database. These patents are not Czechoslovak (only the Czech translation of these patents are in the database).
    These patents are from the years between 1924 and 1938, mostly from Great Britain, Sweden, Germany, and France (one is from Australia).

  9. #9 Klaus Schmeh
    8. November 2020

    Eugen Antal has provided a newspaper article about the Panmilion:ůstojnické-listy-2.pdf

    The article starts on the second page at the bottom of the middle column.