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The Cipher Typewriter

The Cipher

Frederick Sedgwick introduced the Cipher in 1903, casting it as a “proposition without imitators.”1 The typewriter, which was modeled after a Hammond, encoded messages that could be decoded only by a similar machine at the receiving end. Boasted Sedgwick, “It stands alone.”

Crypto-typewriters first appeared late in the 19th century and were employed principally by diplomats and governments, including during the Spanish-American War.2 Sedgwick’s invention did not necessarily stand alone, but he would later claim that his was determined by governments to be “absolutely uncipherable.”3

In 1906,4 Modern Machinery published an article describing the inventor’s motivation, writing, “Mr. Sedgwick… received inspiration toward developing his cipher typewriter from the Dreyfus affair, in which a letter from the waste-basket cost many reputations, a number of lives, and nearly overturned the French Republic, and has never been put to sleep.”

“The inventor has developed the wonderful machine under a feeling of its urgent need and his success has been admirable.”

Another rare image of a Cipher typewriter, published in Popular Mechanics 1917. Describing its operation, the magazine wrote, “The cipher is determined by a detachable plate or disk, containing 30 holes in two concentric circles of 15 holes each. For each of these holes there is a pin and to make a cipher combination this pins may be inserted in or left out of any of the holes, as fancy dictates.” Click here to view the article.

The Cipher produced unique characters each time a key was selected. In one instance the letter “a” might yield an “h” but in another an “m.” Sedgwick claimed his invention could “produce numberless indecipherable ciphers, each differing from the others.”5 To decode the message, the recipient would type the coded message on a second machine, using a key or disc, to reproduce the message intelligiblely.

The Hammond’s rotating type element was key to its operation.

Typing secrets

An illustration from a patent filing in 1898. Based on a Hammond machine with an “Ideal,” i.e., curved, keyboard. This machine and subsequent models resembled Hammond typewriters.

That any Ciphers reached the market in 1903 is uncertain. The American Cipher Typewriter Company, operating out of Chicago, had only just incorporated and advertisements from this period mention only a stock offering. Advertisements placed in the Economist in 1907 mention the sale of the machine. These advertisements individuals interested in securing their correspondence.

In 1916, the trade magazine Office Appliances published an article about the Cipher and included a rare photo6 of a later model (seen at the top of this post). This is one of only a few known images of the Cipher Typewriter. (The machine receives brief mentions in books by Alder, Beeching, and Schiffer, but no images are included.) By this time the American Cipher Typewriter Company had become the International Cipher Writing Machine Company.

The later Cipher has 26 keys: three rows of 9, 8, and 9 (26 total). The top line on a standard typewriter — QWERTYIOP — is 10 keys, so it might be assumed that the arrangement the Cipher was merely alphabetical, i.e., a, b, c, d, etc. Sketches of an earlier machine, based on the Hammmond 1, display a two-row arrangement.7

The later model, from a patent filing.

In 1923, Typewriter Topics mentioned that “the United States government used several Cipher machines, especially built, for secret code communication.”8

That Sedgwick’s machines were built on Hammond designs is plain, but there is no record of a partnership with that company. Further, Sedgwick’s many patent filings do not credit the company. Whether or not his Ciphers were adapted to existing Hammonds or from their designs is unknown. The “rotating” action of the Hammond’s type element was certainly critical to the Cipher’s operation. Its movement could easily be regulated by a controller such as the one Sedgwick designed.

In 1916, Typewriter Topics described the Cipher as “a modification of the ordinary typewriter,” but patent images suggest the modifications were quite significant and perhaps dependent on the Hammond design (most ordinary machines, employing type bars, would not have suited Sedgwick’s purpose).

Sedgwick is briefly mentioned in a court case in 1902 involving Blickensderfer, but only in relation to a person who was in his employ.9 The Blickensderfer, it should be noted, also has a rotating type element.


Sedgwick’s patent holdings include a printing telegraph instrument (U.S. 454884, patented 1891), a battery (U.S. 711537, 1902), an electromagnetic time lock (U.S. 347069; 1886), and several designs for the Cipher typewriter, including:

  • The first Cipher Typewriter, with “Ideal” keyboard (U.S. 727213, 1898)
  • A subsequent model, described as an improvement upon the Cipher Typewriter, with a traditional (non-curved) keyboard (U.S. 1085636, 1914)
  • Further improvements (U.S. 1233715, 1917)

The Baron’s cipher

Bieberstein, the German ambassador to England. He died shortly after his appointment in 1912.

In 1912, a number of newspapers printed an interesting story about a cipher typewriter owned by Baron Marschall von Bieberstein, the German ambassador to England who died shortly after his appointment that year.10 Whether or not the machine described was a Cipher Typewriter is unknown. The reporter himself had not seen the machine, and at times he seems to be guessing about its operation.

The article begins: “Now comes the secret typewriter — not a young woman who knows how to hold her tongue, but a machine, whose keys write a sort of cryptogram instead of the commonplace alphabet.”

Londoners found Bieberstein quite mysterious,11 and possessing a crypto-machine only deepened his mystique.

Continues the article, “His typewriter, they say, writes a cipher that only himself and a highly confidential clerk in the German foreign office can read. He works the machine himself and it is said that he keeps it under lock and key and allows nobody else to write with it.”

This machine, according to the article, did not employ a QWERTY (or QWERTZ!) layout, but some other random arrangement, and produced different letters each time a key was pressed.

The article claims that “any stranger having a few minutes access to the machine might copy the secret code with absolute accuracy, and thus destroy the utility of the device,” a claim that seems to oversimplify the machine’s operation. Note that this cipher effected a different letter each time a key was pressed. Deciphering the coded message may not have been as simple as knowing the keyboard arrangement, as some decoding key would be necessary to produce a message from a jumble of random letters.

To maintain the secrecy of the cipher, the article notes, “the dies for the type have to be specially cut and usually must be turned over to the buyer along with the machine.”

“Generally, it is said, it is found better to have an untrained typist learn the cipher machines, and use no other, as an operator writing the ordinary alphabet is very apt to relapse into it in the middle of a cipher despatch through absentmindedness or force of habit, thus destroying the legibility of the product.”

Tyrowski’s cow

In 1906, the following headline appeared in the Chicago Tribune: “Cow Causes Trouble for Head of Typewriter Co.” Apparently, Sedgwick disputed with Kate Tyrowski, the wife of a wealthy jeweler, over the grazing habits of her cow Dearie.

Sedgwick was frustrated that Dearie “was grazing on his property” and promptly locked the animal in his barn. Later, Tyrowski searched for Dearie and hearing “a familiar moo” found the animal in Sedgwick’s barn. She demanded the animal back, but Sedgwick refused, turning it over to the poundmaster. Tyrowski paid the fee and then demanded Sedgwick’s arrest.

How the case was resolved is unknown, but two accounts of the dispute are included below.

From the Chicago Tribune, May 26, 1906…

From the Inter Ocean, May 26, 1906…


There are scant references to the Cipher Typewriter, as its appeal would certainly have been limited to certain applications. As mentioned above, governments and diplomats seemed to be the primary customers. Here are some of the documents available online:

From the Evening Courier, Camden, New Jersey, Feb 11, 1903…

From the Chicago Tribune, April, 19, 1903…

From the Phonographic Record, 1904…

From Mondern Machinary, 1906 (click image to view in Google Books)…

From Office Appliances, August 1916 (click image to view in Google Books)…

From Typewriter Topics, October 1916…
Click this link to view PDF.

© 2018, Mark Adams. All rights reserved.

  1. Advertisement for the American Cipher Typewriter Company in the Chicago Tribune, April, 19 1903. []
  2. See this post on the use of new cipher typerwriters during the Spanish American War, click here. []
  3. Office Appliances, August 1916. []
  4. Corrected. Original post read 1917. []
  5. US Patent 1,233,715. []
  6. Granted, this could also be a sketch. []
  7. See Martin Howard’s Hammond here. []
  8. Citing Sedgwick’s design specifically, Typewriter Topics, October 1923. []
  9. See here. []
  10. The Edmonton Journal, Alberta, Canada, July 18, 1912 []
  11. See this entry about the ambassador here. []
{ 3 comments… add one }
  • Bill M November 26, 2018, 12:35 am

    I never knew such a typewriter existed although I had read about later cipher machines that were used in WWII.

  • T. Munk November 26, 2018, 4:09 am

    Hmmn, certainly not one I’ve heard of. I wonder if cipher machines would count for the TWDB, but I see that this particular model probably would 😀

    • Mark Adams November 26, 2018, 5:03 pm

      I would classify the Cipher as a specialty typewriter, analogous to bookkeeping or mill typewriter. While there were many encryption machines/devices in that period, the Cipher was intended to be a typewriter for secure communications.

      There are no known models, but illustrations from patent filings and periodicals indicate at least two: one based on the Hammond 1 design (w/ ideal keyboard) and one based on the Hammond 2 design (w/ straight keyboard). Typewriter Topics, 1916, wrote, “The cipher typewriter, invented by Frederick Sedgwick, is a modification of the ordinary typewriter and is intended to safeguard private letters, telegrams, etc.”, but patent images suggest something more comprehensive than a simple attachment. There does appear to be two versions of the Hammond 2 type, as seen in the images in this post.

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