US2435130A - Cryptographic attachment for typewriter keys - Google Patents

Description

' Jan. 27, 1948. R. N. CUNNINGHAM 2,435,130

- CHYPTOGRAPHIC ATTACHMENT FOR T YPEWRITER KEYS Filed Oct. 5, 1944 1 2 Sheei :s-Sheet 1 a 5 w i k Jan. 27, 1948. R. N. CUNNINGHAM 2,435,130

GRYPTOGRAPHIC A'r'mcaumr ron 'ryrxwm'rnn KEYS Filed Oct. 5, 1944 v 2 Sheets-Sheet 2 RMCannz'ngfiam I Patented Jan. 27, 1948 CRYPTOGRAPHIC ATTACHIHEN'I' FOR TYPEWRITER KEYS mi; N. Cunningham, Washington, D. 0.

Application October 5, 1944, Serial No. 557,346

ZQlaims.

This invention relates to cryptograph systems and to a means for adapting an ordinary or standard typewriter keyboard to such system.

An object of this invention is to provide an attachment for the keys of a typewriter in the Iorm 01 caps fitting over the present keys, the caps being in the form of removable code caps which are formed in such manner that the characters of the original keys are visible therethrough. In one form of the invention the code caps are formed with a top wall having a central transparent window whereby the characters of the original keys may be viewed therethrough, and in another form of the invention the top wall of the cap is formed with a central opening for exposing to view the character of the key. In each form of cap the arrangement of the code characters is the same, such characters being arranged circumferentially about the window.

The code system to be hereinafter described embodies four codes, each one of which is identifled by a particular color and position on the code cap. In the coding of a message any single series of code characters may be used, or the coded words or groups of characters may embody two or more of the code series, and where two or more of the code series are used, the code series may be used in a prearranged sequence, and such sequence may also be varied for each coded group of characters, thereby forming a non-uniform code which will make it practically impossible to decode without prior knowledge of code series sequences used.

Another object oi. this invention is to provide an improved method of forming a code system which is capable of numerous variations or combinations of codes so that an uniniormed decoder will be unable to translate or break the code.

To the foregoing objects, and others which may hereinafter more fully appear, the invention consists of the novel construction, combination and arrangement of parts, as will be more specifically referred to and illustrated in the accompanying drawings, but it is to be understood that changes, variations, and modifications may be resorted to which fall within the scope of the invention as claimed.

In the drawings:

Figure l is a diagrammatic view of a conventional typewriter keyboard, having a crypto- 2 7 graphic means mounted thereon in accordance with this invention.

Figure 2 is an enlarged plan view ot a series or typewriter keys having cryptographic caps mounted thereon.

Figure 3 is an exploded view showing in top plan the cryptographic cap together with the crimped holding ring for the conventional indicia plate on the key.

Figure 4 is a sectional view taken on the line 4-4 of Figure 2.

Figure 5 is a top plan of a series of keys having mounted thereon a modified form of cryptographic attachment.

Figure 6 is a. sectional view taken on the line 6-6 of Figure 5.

Referring to the drawings, the numeral in des-- ignates generally a conventional keyboard for a typewriter, havin key bars ii formed with head I2 on which a plate I3 is mounted bearing the indicia M. The plate 13 is held on the top of the head i2 by means of a crimped ring-'5. A cap generally designated as it is mounted on the key, engaging about the ring 15, and includes a top wall l'i, which is of concave configuration on the upper side and is provided with a cylindrical skirt l8 engaging about the ring [5 and frictionally held thereon.

The top wall I! is preferably cf opaque material and is formed with a, centrally disposed transparent wall portion l9. The transparent wall portion i9 is provided so that the character l4 ot the key bar will be visible through the cap l6. There is one cap l6 for each one of the key bars or keys.

In order to provide a means whereby the typewriter may be used for both coding and decoding a message, I have provided on the upper side of the top wall I! about the window or transparent portion IS, a plurality of characters 20, ii, 22 and 23. The characters 20 to 23 are alphabetical characters, but are different from the character of the particular key bar. In arranging the several series of code characters, as herein disclosed, there are four series of code characters with the alphabetical characters of each series scrambled so that there will not be any definite sequence or relation of a code character to the normal alphabetical character on the key bar.

There is given below a tabulation, showing the CcdeSeriesNo. '1UQHYOPWCZMTNJLEFBSRKAXGVD 2FHLPGAEBNSVCUIXDYWJZMKROQ' E' 3RVEOCXKUSYGPTWDLZAIMHBNFJQ 4 CPAFODSLWZTHVREBVNGKYQIMUJ .The following is a simple form or use of the and the top wall ll is formed with an opening tation.

123412341 234123412 3412341 #1 KBCGDJMOJ BRGFWDQOP'DDXFPYO -4321432l4-32l432l43 2143214 #4-KUGRUIZOUUFRBAXXO0XPQRCAO I Where the series of codes are usedtogether and A a -s m m 1 m t fact that in sequence, the initial code word is preceded by a As an example, if the sequence is 1, 2, 3, 4, the

differentiation in the colors of the characters of ticular positions of' the code characters 20 to 23 four codeseries and their relation to the normal alphabetical characters appearing on the key era;

In Figures 5 and 6 there is disclosed a slightly modified form of this invention, wherein the code caps l6 are formed with an opaque top wall l1 ABCDEFGHIJKLMNOPQRSTUVWXYZ characters of eachvcode series. As an example, 24 instead of a transparent window. The key the sentence, The-system has proved of value" bar character is visible throu h he 0 g is coded as follows for each of the four code g t pemng 24 in the same manner as the key bar character is series. 7 visible through the transparent window is of cap #1 KCORDRKOJ CURFSEXOY, EPXUNAO 5:25 ggglagiggg It will be understood that while referenceis R made to the code 5 st m mbod #4 KLOGUGKOV LCGBNEQOF- EDQCHYO y e e ymg four codes that there might be a lesser or a. greater number than four, and it is contemplated that the invention-shall be construed as being of such scope. Likewise, where the term cap is used, it will be understood to include a ring or a, skirted annulus. the scope of the termrbeins intended as a word of general designation and not a: a word of limi- Another method of using this code system is to use all four code series in the formation of the code words or characters, and thenseveral series may be used in sequence. This sequence maybe either in the sequence of the numbered series such as l, 2, 3, 4, or the sequence maystart with any preselected series:

the typist can use the machine in the ordinary the numeral of the first series. of thesequence. manner with the standard keyboard and. if

sired, can switch at any pointin the message to code merely by'observing the selected adjacent symbol. This is a great advantage in a device of 40 this character. Furthermore, in decoding, the typist can easily observe the standard letters as well asthe selected code letters, no alteration of the keyboard or interference with the .normal use M 5 of the machine being required.

What I claim is:

1. As a new article of manufacture a cryptographic attachment comprising a cap engageable over one key of a typewriter, said cap including a top wall having a centralformation through which the character of-said key will be visible,

. a cylindrical skirt about said top wall engageable about: said key,-an'd circumferentially. spaced apart code indicia on the uppersurface of. said wall surrounding said central formation, said code indicia denoting characters different from the character ofsaid key whereby. a code character may be written or transcribed inaccordance withany one of. a plurality of difierent code 0 systems by striking the keyhbearingthe code indicia.

2. As a new article of manufacture a cryptocodewordis:

' fl KBGGD-JM-OJ Where the code series is in-reverse sequence, the code word is also preceded by the numeral designating the first series starting the word, such as #4 KUGRUIZOU As another example, the code series may be used alternately. such as series 2 and 4, or reversely 4 and 2,- as indie ited below:

Where alternate code series are used, the first code word is preceded by the two numerals designating the sequence of the code series. such as:

,- 24 ZLGGQGZ0J 42 LFGDNXQGF The above are only a few examples of themanher in which the code series may be used. In order to assist-in codinr: and decoding themessage, the characters 20 of the first cOdeseries may be colored red; the characters of the second code series may be colored blue; the characters of the third code series may be colored red; and graphic attachment comprising a cap engageable the characters of the fourth series may be colover -'a,:keyof a. typewriter, said cap including a cred black. It will. of course, be understood that top wall having a: transparent central panel the characters on the caps the coding and whereby-the character of said .kcy may be viewed, the decoding machine Wm be identical, and the a cylindrical skirt aboutsaid top wall engageahle at said ke and circumferentially spaced the different code series is-designed to facilitate abo y both the coding and the decoding of the message. igg i' g'fi z gg fi gg g zggz zfg fg 223:3

panel, said code indicia denoting characters different from the character of said key whereby a nude charactermay .be written or, transcribed 7 in accordancewith any-one of a plurality of dif- However, if desired, the characters 20 to 23 may be all of the same color, and the coding and decoding of the message is accomplished by the paron the surface of the cap.

ve ul-ullm.

aegan ferent code systems by striking the key bearing Number the code lndlcia. 1,541,043 ROY N. CUNNINGHAM. 1,203,570 7 442,374 7 REFERENCES CITED 5 527,112 The following references are of record in the me of this patent: )3351 7 1,718,694

UNITED STATES PATENTS Number Name Date m 1.093.372 Allum et a1. Apr. 14, 1914 Number $085,166 97,890

Nolte June 29, 1937 Name Date Graham June 9, 1925 Beaubien Nov. 7, 1916 Wler Dec. 16, 1890 Harte Oct. 9, 1894 Hebern et a1. Feb. 10, 1914 Kanschine Sept. 12, 1911 Kurowskl June 25, 1929 FORFHGN PATENTS Country Date Switzerland 1923

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