Edward Hebern was a bustling, yet successless constructor of cipher machines. The Smithsonian Institution has put a number of photos of these devices into the public domain.

Edward Hebern (1869-1952) was a notable figure in the history of cryptology. After a deprived youth, he lived the life of a farmer in California, before he had to serve a prison sentence because of horse thievery. While in jail, around 1908, he had the idea of constructing an electromechanical encryption machine, which led to his first patent being granted in 1914. Hebern built the first rotor-encryption machine, years before the Enigma came to the market with a similar design.


Edward Hebern

Hebern was apparently a good craftsman and did a good job in convincing others of his ideas. He sold about a million dollars’ worth of stock in his company Hebern Electric Code and built an impressive neogothic factory building in downtown Oakland (I had the pleasure to visit this place in 2016).

Source: Schmeh

This three-story structure was built to accommodate 1,500 workers and included a luxurious office for Hebern. Today it is located in Oakland’s chinatown, hosting, among other things, a juice and smoothie store.

However, Hebern, who had never attended a university, was not a particularly good businessman. In addition, the demand for encryption machines was still low in the 1920s, which led to neither Enigma inventor Arthur Scherbius nor Boris Hagelin, who later became the most successful crypto device producer ever, nor “cipher aristocrat” Alexander von Kryha to never make substantial revenue from cipher technology in those days. Edward Hebern’s company inevitably went bancrupt and Hebern had to retire from the crypto business.

Today, Edward Hebern’s encryption machines are sought-after collectibles. I know of about ten devices of this kind to exist, which makes even the Enigma (some say that about 1,000 specimen have survived until today) look like bulk good.

Here’s the only article about Edward Hebern I’m aware of.


The Smithsonian pictures

My friend Tobias Schrödel, known as comedy hacker, crypto book specialist and encrypted postcard collector, has recently pointed out to me that the Smithsonian Institution has put 2.8 million images in the public domain. Tobias suspected that this huge collection includes crypto-related material, and he was right. When I searched the Smithsonian website for items tagged “cipher” or “encryption”, I immediately received a few interesting results. Most of all, I found dozens of photographs of Hebern encryption technology I had never seen before. In the following, I’m going to introduce a few of these pictures.


An early Hebern prototype. The lamps that indicate the cipher letters are still separated from the keyboard. Source: Smithsonian Institution


This Hebern machine, placed in a purple-lined suitecase, was certainly not designed for military customers. Just like the Enigma and the Kryha machine, the Hebern devices were offered to civil customers such as banks or international corporations, but completely failed on this market. Source: Smithsonian Institution


This Hebern machine worked with only one rotor (which is missing here). Later designs had up to five rotors. Source: Smithsonian Institution


Another one-rotor Hebern model, probably made around 1920. Source: Smithsonian Institution


Edward Hebern expected to sell a large quantity of his machines to the US Navy. This never happened. Only in the 1930s, the US miltary introduced rotor machines, when Hebern was long out of business. Source: Smithsonian Institution


One of Hebern’s many one-rotor designs. A far as I know, the evolution of Hebern’s machines has never been researched. Source: Smithsonian Institution


This five-rotor encryption machine is one of Hebern’s most advanced designs. Most or even all of the Hebern machines still existing today are unique; I have never seen two of the same kind. Source: Smithsonian Institution


All of Hebern’s later models were based on wired rotors. This method proved extremely successful in the 1930s, but Hebern, who was active ten years earlier, never sold his designs in notable amounts. Source: Smithsonian Institution

Thanks to Tobias for informing me about this great picture collection and thanks to the Smithsonian Institution for putting it into the public domain.

Further reading: Hidden message discovered on tombstone of famous cryptologist couple

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Kommentare (15)

  1. #1 Richard SantaColoma
    21. März 2020

    I think there is something really incredible about the image titled, “An early Hebern prototype. The lamps that indicate the cipher letters are still separated from the keyboard.”

    The glass objects on the right are actually 6A5 “Octal” vacuum tubes. The octal type tube was first on the market in 1935, and the “triode” type was used primarily as an amplifier:


    But these triodes could also be used as electrical/electronic contact-less switches. The implication of this is that Hebern was very early on using these not only AS switches, but in a cipher machine. Could this then be the first electronic cipher machine?

    From: https://en.citizendium.org/wiki/Electronic_switch

    “The ability of triode vacuum tubes to act as switches (on/off devices that stop or start an electrical current) would later be important in the building of the first electronic computers. When used as an “on/off” switch in a computer, vacuum tubes were also sometimes called electron valves, or just valves. Unlike relays, vacuum tubes expose no physical armature contacts to break or get dirty, and they are faster than relays. But they also cost a lot to manufacture, consume a lot of power, give off a great deal of heat, and tend to burn out often.”

    Later, triodes were used in the first electronic computers. The earliest example was the Atanasoff-Berry computer:


    I would love to see the wiring diagram of this Hebern tube unit, and the date he built it. Perhaps his past due credits should include electronic logic circuits, among his other “firsts”.

  2. #2 Kerberos
    21. März 2020

    Hallo Hr. Schmeh
    im rechten Teil des Bildes hebern-5.png sieht man nicht
    “Lampen*” sondern Röhren, nach Schrift am Sockel
    Fabrikat Raytheon.
    Das könnten Gleichrichterröhren oder Endtrioden sein, aber diese Kolbenform gab es erst in den 30ern.
    Existierte die Firma noch in den 30ern?
    Außer evtl in Österreich, das als “Philipsland”
    das niederländische “Lampen” von deren
    “Radiolampen” übernahm.

  3. #3 Klaus Schmeh
    21. März 2020

    @Rich and Kerberos: Thank you for your comments. To my regret, I have no idea if and why Hebern used triods. He died in the 1950s, so it seems possible that he still worked on cipher machines in the 1930s.

  4. #4 Kerberos
    21. März 2020

    Hello Richard SantaColoma,
    “”When used as an “on/off” switch in a computer, vacuum tubes were also sometimes called electron valves, or just valves.””

    Tubes were called tubes in USA, but Valves in GB.
    Irrespective whether used on/off or analog.

  5. #5 Ralf Buelow
    22. März 2020

    Well – Smithsonian’s description of the vacuum-tube prototype is here for everyone to read: https://americanhistory.si.edu/collections/search/object/nmah_1214327 or written out: “The keys are linked to electrical contacts. Some wires attach to a squat cylinder mounted horizontally on top of the machine. A capacitor is behind this cylinder on top, a motor to the left. Other wires are connected to a panel on the front of a large metal box. Holes in the top of the box hold a 5×5 array of vacuum tubes. There are three more tubes in back of the array, one smaller than the others. There is a condenser on each side of these three tubes. In back of these is a row with two large transformers on each side, a choke, and a small transformer. A back panel attached to the box contains a switch, a light and an ammeter. A large round plug is attached to numerous wire coming out of the box. A cord with smaller round plugs at each end fits the keyboard on the right side. The end of the plug that fits into the keyboard has a torn slip of paper around it. At the other end is tied a second torn slip of paper. A third, two-pronged plug extends from the keyboard and has a paper label tied around it.

  6. #6 Kerberos
    22. März 2020

    Hallo Hr. Bülow,
    there is a little “problem” in this description:
    “”Holes in the top of the box hold a 5×5 array of vacuum tubes.””
    If one is able to count up to six tubes, one will see a
    6×5 array

  7. #7 Gerd
    22. März 2020

    Very interesting find, could be the first “electronic” machine. However I see a 6×5 array of tubes, not 5×5.

  8. #8 Kerberos
    22. März 2020

    In the
    linked article are some some lines of a poem by Hebern :

    Marvelous invention comes out of the West
    Triumph of patience, long years without rest
    Solved problem of ages, deeper than thought
    A code of perfection, a wonder, is wrought.

    Whover wrote that poem had been inspired by
    Sir Walter Scotts “Lochinvar”:

    “”O young Lochinvar is come out of the west,
    Through all the wide Border his steed was the best;
    And save his good broadsword he weapons had none,
    He rode all unarm’d, and he rode all alone.
    So faithful in love, and so dauntless in war,
    There never was knight like the young Lochinvar. “”

  9. #9 Richard SantaColoma
    22. März 2020

    Thank you, Ralf, I missed that description.

    I would still be interested in seeing the wiring diagram (schematic) of this device, and how Mr. Hebern was using this array. Maybe they have this, too, in their collections… perhaps I will drop them a note and ask.

    I am thinking the 6×5 array is the only switching section, and that the other tubes, capacitors and components are part of the power supply and so on. The filament string for all the tubes was 6.3 volts direct current (hence the “6” in 6A5), and so it would need the line voltage regulated from 120 or 220 AC, as is done in most radio circuits. So one of those other tubes is probably a “rectifier” (converts AC to DC), and then the large capacitor (an electrolytic power cap) would be to filter out the line voltage “hum”.

    This would not be a battery unit, the power requirements would have been far too high to be practical in the 1930’s. And the additional components suggest a power supply, so this was almost certainly powered “from the wall”.

  10. #10 Richard SantaColoma
    22. März 2020

    … I forgot to mention that the two large units seen at the “back” of the tube array section are transformers. One of these would have been used to reduce line voltage from 120 or 220 to the necessary 6.3 volts for the tube filament string.

    The second large, and two other smaller transformers? Not sure. But it implies there was a second voltage requirement in this circuit. It could be the necessary voltage for the tubes plate or grid voltage, in order to work the switching function. That would be higher than the filament voltage.

    This unit is turned around. There is an upright panel on the front, and we can see the back of it. That center unit is almost certainly a voltmeter or ammeter, so that an operator could adjust the voltage in the circuit.

    But what would be very exciting would be if that voltmeter was an indicator of some kind, as in a readout of some result… but I doubt that. It is probably only to monitor the running current, which was not a stable as it is today.

  11. #11 Gerd
    22. März 2020

    The US patent 1945028 printed on the Bodine motor has been issued 30 Jan, 1934. That matches to the 6A5 tubes that appeared 1935.

  12. #12 Kerberos
    22. März 2020

    “”The filament string for all the tubes was 6.3 volts direct current (hence the “6” in 6A5), and so it would need the line voltage regulated from 120 or 220 AC, as is done in most radio circuits.””

    those tubes were operated with AC for the filament.
    They needed 1.2 Amperes each, 36 Amperes for 30 tubes!.
    Rectifiers for such currents were available starting
    from 1950 (Selen, not very popular in US), or
    in 60ties as silicon rectifiers.
    The tube(s) you think were used as rectifiers in the background
    would deliver around. 50 mA!
    The capacitors You believe to be electrolytic are
    paper wound, see here:
    Paper wound and 8 µF at this size means the capacitors
    are of the self-healing MP type (Bosch. first produced after WWII for civil use)

  13. #13 ralfandreas@web.de
    22. März 2020

    @ Richard SantaColoma ….note that the Smithsonian link https://americanhistory.si.edu/collections/search/object/nmah_1214327 opens not only one but several more photos – please look at the little arrows at the side of each picture.

  14. #14 peter
    23. März 2020

    A data sheet for that tube, 6A5G can be found here
    https://frank.pocnet.net/sheets/201/6/6A5G.pdf . For other types of tubes see here: https://frank.pocnet.net/sheetsE1.html . The “G” is clearly visible below “6A5”.

    The 6A5G is a huge amplifier valve (for the 1930ies) with a usable audio output of 3.5 W (single ended) and of 15W with two tubes in push-pull! in the 1930ies there were probabely tubes much cheaper and less power consuming for switching signals or “computing”. 30 tubes could produce more than 200 W!
    Could it be, that those tubes were used to change the frequency of the AC current for the motor of the enryption device? Ham radio operators used in the 1970ies such frequency changers to run teletype machines with other transmission speeds as designed.

  15. #15 Richard SantaColoma
    24. März 2020

    Kerberos: Good points. The filament string for vacuum tubes such as this could be AC or DC, but I agree you are probably correct, and AC was used in this device. I see your point about the massive current needed for so many tubes. Also, in the other pictures I would say the additional tubes are not rectifiers, as I thought at first.

    But there may also be a selenium rectifier stack under the chassis, because they do actually fit the time frame. I think it is possible that one of those could handle such current, although they would get pretty hot. It would be great to see a picture of the underside.

    Thanks Ralf! That is easier than scrolling through all the unrelated photos of other machines.

    Peter: The “G” in the designation 6A5G means “glass”, that it has a glass envelope, rather than metal. The wiring, internals and function are not different between a metal and a glass envelope. I shouldn’t have left the G off, it was just a convenience on my part, I suppose. But I still think these were being as switches here, because that is, to me, the implication considering the context of a cipher device, and the type of array used.