Electrical cryptograph (original) (raw)

US2877565A - Electrical cryptograph - Google Patents

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Publication number

US2877565A

US2877565A US549086A US54908644A US2877565A US 2877565 A US2877565 A US 2877565A US 549086 A US549086 A US 549086A US 54908644 A US54908644 A US 54908644A US 2877565 A US2877565 A US 2877565A

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US

United States

Prior art keywords

switch

rotors

rotor

cam

lamp

Prior art date

1944-08-11

Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)

Expired - Lifetime

Application number

US549086A

Inventor

William F Friedman

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Individual

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Individual

Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)

1944-08-11

Filing date

1944-08-11

Publication date

1959-03-17

1944-08-11 Application filed by Individual filed Critical Individual

1944-08-11 Priority to US549086A priority Critical patent/US2877565A/en

1959-03-17 Application granted granted Critical

1959-03-17 Publication of US2877565A publication Critical patent/US2877565A/en

1976-03-17 Anticipated expiration legal-status Critical

Status Expired - Lifetime legal-status Critical Current

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Description

March 17, 1959 w. F. FRIEDMAN ELECTRICAL CRYPTOGRAPH 4 Sheets-Sheet 1 Filed Aug. 11, 1944 MN 4 M a 7 W e F M M L l W dwsw m-L12.

March 17, 1959 w. F. FRIEDMAN 2,377,555

ELECTRICAL CRYPTOGRAPHJ Filed Aug 11. 1944 4 Sheets-Sheet 2 March 17, 1959 w. F. FRIEDMAN ELECTRICAL CRYPTOGRAPH 4 Sheets-Sheet I5 Filed Aug. 11. 1944 WILLIAM E FRIEDMAN AT TORNE Y March 17, 1959 w. F. FRIEDMAN 2,877,565

ELECTRICAL CRYPTOGRAPH Filed Aug. 11, 1944 4 Sheets-Sheet 4 FIGURE 8 FIGURE 9 WILLIAM E FRIEDMAN INVENTOR ATTORNEY United States Patent ELECTRICAL CRYPTOGRAPH William F. Friedman, Washington, D. C.

Application August 11, 1944, Serial No. 549,086

8 Claims. (Cl. 35-4) (Granted under

Title

35, U. S. Code (1952), see. 266) The invention described herein may be manufactured and used by or for the Government for governmental purposes, without the payment to me of any royalty thereon.

This invention relates to a device or machine, which may be used either as a cryptograph for enciphering and deciphering communications, or as an authentograph for testing the authenticity of messages.

The primary object of this invention is to provide a cryptograph or cipher device which is simple in construction and maintenance, but nevertheless affords a high degree of security, is light and readily portable, and can be readily dissassembled and rearranged to vary the cipher keying elements.

Another object of this invention is to provide an authentograph, that is, a device for testing the authenticity of a message or signal, thereby providing means for assuring that such a message or signal originated at an authorized source and is to be considered authentic.

An additional object is to provide a novel keyboard for use with a cryptograph and an authentograph.

Another object is to provide a novel method for the authentication of messages.

Other objects of the invention will become apparent from a reading of the following specification and claims.

In the drawings:

Figure 1 is a top or plan view with the covers closed.

Figure 2 is a top or plan view on an enlarged scale with the keyboard cover and parts of the rotor cover omitted.

Figure 3 is a side elevation with the covers closed.

Figure 4 is a cross section on line 4-4 of Figure 2 with the rotor cover omitted.

Figure 5 is a perspective view of the rotor latch.

Figure 6 is a perspective view of the rotor actuating mechanism.

Figure 7 is a diagram showing schematically the electric circuits and the mechanical operating mechanisms.

Figure 8 is a view of a portion of the device, illustrating a modified keyboard and switching means.

Figure 9 is a view of a rotor such as is used in the device of this invention.

The embodiment of the invention selected from among others for illustration in the drawings and description in the specification is as follows. Referring to Figure 7, the device will be seen, in general, to consist of a

source

10 of electricity, connected to a pair of wires 11 and 12 across which are connected a plurality (in this instance, twenty-six)

indicators

13A, 13B, 13C, etc. These indicators are illustrated as being electric lamps arranged beneath a keyboard and indicator panel 14 (see Figure 2) and each arranged to illuminate one perforation closed by a transparent cover 15 hearing one letter 16 of the alphabet thereon.

Panel

14 is secured in place over a

gasket

14 of soft rubber or the like by means of screws as 14". Across lines 11 and 12 are also connected manually

operable switches

17A, 17B, 170, etc., each in series 2,877,565 Patented Mar. 17, 1959 with one of the

indicators

13A, 133, etc., arranged for operation by pushbuttons 18 projecting through

keyboard

14 in proximity to the covers 15.

Connected to each of the

indicators

13A, 138, etc., is a multicontact electric switch, generally indicated as 19. It comprises a number of relatively juxtaposable and rotatable cryptographic switching wheels or rotors, 19A, 19B, 19C, and 19D, in cascade, each rotor having a plurality of spring input and output contacts 19' thereon (see Figure 9), and a final wheel 19E, which may hereinafter be called the reflecting rotor or reflector, the output contacts of which are connected in pairs, as shown diagrammatically at 20' in Figure 7. Each electrical path, as 20, through the

rotor system

19 leads from one

stationary contact

20 through the cryptographic rotors, and back, through 20', to another

stationary contact

20". These paths or

circuits

20 are rearranged each time one of the rotors is turned.

In conductor 11 there is a normally'closed

electric switch

21. Between one of the indicators, in this case 1315, and

multi-contact switch

19, there is a normally closed electric switch 22. In parallel with wire 11 is wire 11A containing an

authenticating switch

23 having an

operating handle

24. Wire 11A also contains a normally-

open switch

25.

Turning now to Figures 1, 2 and 3 for a disclosure of the mechanical features of the invention, the device is shown as enclosed in a

casing

26 to which are hinged or otherwise attached a

back cover

27 and a

front cover

28.

The front cover, protecting the keyboard, is secured to casing 26 by means of a

double hinge

28', 28". This arrangement permits the cover to fit snugly upon

gasket

14'. thereby to provide a substantially dust-proof and water-proof closure for the

keyboard

14, and yet permits it to lie flat in front of the machine or to be folded therebeneath. The back part of the

casing

26, adjacent the rotor assembly, is provided with a lip 26' (see Fig ure 2).

Back cover

27 is adapted to fit over this lip, and has a

gasket

27, which provides, upon closure of the back cover, a dust-proof and moisture-proof seal. The front and back covers when closed are secured by means of

hasps

23' and 23", respectively.

In the top of

casing

26 there is an opening 29 through which a

counter

30 is visible. As is most readily seen in Figure 6,

casing

26 has two projecting walls 26A and 263, which are supported and strengthened by a rod 26C. The

cryptographic switching assembly

19 is retained between these walls by a mechanism which will now be described. Wall 26A has an orifice therein through which may be pushed

pin

30A having a knurled head 31 (Figure 2) and a

latch

32 cooperating with a retaining spring 33. Also pivoted on wall 26A is a

spring latch

34 of U-shape, one arm being bent back parallel to the other. The free end 34A of

latch

34 is perforated to allow

pin

30A to pass through it and bears

cam surfaces

35 thereon.

Stationary cam

36 has a surface complementary to

cam surfaces

35 so that when

latch

34 is moved from the substantially horizontal position, in which it is shown in Figures 2, 4, and 6, into the vertical position, in which it is shown in Figure 5, the free end 34A of

latch

34 is moved away from wall 26A and compresses the entire rotor-reflector assembly so as to insure good contacts through the spring contacts 19' thereof.

The manually operated means for rotating the

cryptographic rotors

19 will next be described. As seen in Figures 1, 2, 3, and 6,

casing

26 has a

recess

37 in its top into which fits a plunger consisting of

fingerpiece

38 having a sliding fit in the recess and a

rod

39 upon which the fingerpiece is mounted.

Rod

39 causes U-shaped

stirrup

40 to turn on its pivots in walls 26A and 268. On stirrup 40 is a

cam

41, which

actuatesfollower

42 fast on

shaft

43 of

counter

30. Stirrup 40 also has a

member

44 to which

spring

45 is attached and which carries cam face 46. Detent 47 is pivoted at 48 in walls 26A and 26B and is stressed by

spring

49 so that cam 50 engages cam face 46.

Spring detents

60 normally hold

rotors

19 in their relative positions but allow movement of these rotors under the actuation of

pawls

58.

Detent teeth

51 are moved in and out of the ratchet depressions in the surface of the

rotors

19 upon each movement of

stirrup

40, as will be hereinafter further described.

Stirrup

40 carries a

pin

52 on which are pivoted a plurality of cam-and-pawl devices, 53A, 53B, 53C, and 53D, which are urged by

springs

54 against the rotors (see Figure 9). Device 53B, for example (Figure 6), has a earn 553 and a pawl 58B, and these are adapted to co operate, respectively, with

ratchet depressions

56 of

rotor

19A and pawl notch 55D on the rotor 19B.

The operation of this device is as follows:

Cover

28 is opened to expose the

keyboard

14. If, as frequently happens, limitations of space require, the cover may be folded back beneath the machine. For enciphering or deciphering, handle 24 is operated so that

switch

23 is open. That push button 18 which is associated with the desired letter is depressed and the switch controlled thereby is operated. For example (to encipher the letter B), if push button 18 associated with the letter E is depressed, switch 17E (Figure 7) is thereupon closed, and connection is made from battery through line 11,

switch

21,

line

118,

switch

17E, lamp 13B, and line 12 back to

source

10, illuminating lamp 13E. This action also closes connections from

battery

10 through lines 11, 11B, through

switch

17E, then along line 110, through switch 22,

line

20, thence through

rotors

19A, B, C, D and reflector 19E, rotors 19D, C, B, A, to line B, lamp 13Z, thence through line 12, back to

source

10. Lamps 1312 and 132 are simultaneously lighted, and this indicates that the cipher equivalent of the letter E is Z. To decipher the letter Z, the push button 18 associated with the letter Z is depressed and the circuit is as follows:

battery

10, line 11,

switch

21, line 11D, switch 172, line 20B, through the rotor-reflector assembly,

line

20, switch 22, line 11C, lamp 13E, line 12, back to

battery

10. Lamp 13E would be illuminated, giving E as the plain-text equivalent of Z. At the same time the lamp 132 would also be lighted by the closing of switch 172 and by a circuit which is essentially similar to the one described in connection with the closing of

switch

17E. Thus, since

rotors

19 connect all the

lamps

13A, 13B, etc., and all the

switches

17A, 17B, etc., together in pairs, each letter has another corresponding to it.

For rotating the

cryptographic rotors

19 and thus varying the connections between the various pairs of lamps 13 and switches 17, the

plunger

38 is depressed, stirrup is rotated about its pivots and the members 53A, etc., moved. A

pawl

58 will normally ride on a

rim

57 of a rotor, and, under these conditions, its associated cam face 55 cannot enter a ratchet depression to step an adjoining rotor notwithstanding the urging of its

spring

54. As soon, however, as a pawl falls into a pawl notch 55D it and its cam member move upwardly somewhat and toward the rotors and the latter engages a ratchet depression. Then, on movement of

stirrup

40, the rotor in question is stepped. It will be noticed that, in view of the manner in which tang 59 of device 53A underlies device 53B, etc., device 53A cannot move upwardly unless device 53B has so moved. The pawl member of

device

53D rises on each operation of

stirrup

40, as it drops over shoulder 58' of member 60'. The result is that rotor 19E steps each time the

stirrup

40 moves, rotor 19D steps once for each revolution of 19E, 19C steps once for each revolution of 19D, etc.

It is, in other words, the

cam face

55 engaged in a

peripheral slot

56 and impelled by rotary motion imparted to it by plunger 38-39 which actually serves to step the rotor. The cam face cannot, however, enter into one of the notches until the cooperating pawl enters an auxiliary notch 55D.

Whenever a

cam

55 drops into a

notch

56, and the movement of the

plunger

39 is completed, the corresponding

rotor

19 is moved one step. This re-arranges the connections through the rotors and connects different pairs of

lamps

13A, etc., together.

Counter

30 is moved one numeral because

follower

42 is depressed by

cam

41 and spring returned.

Detent

47 prevents overstepping of the

rotors

19 because

teeth

51 enter notches in

rotors

19.

A detailed description of the operation of the device as an authentograph for insuring the authenticity of a message or a signal will now be given. Assuming that agreement has been previously reached by the two parties concerned as to the wiring of the several rotors and their arrangement in the device, the counter is set to zero, and switch 23 is closed by snapping

handle

24.

Plunger

39 is then depressed, opening switches 21 and 22 and closing

switch

25. This movement moves counter 30 one position forward and also one or

more rotors

19 one step. The following circuit is then established:

Source

10, line 11, line 11A,

closed switch

23,

closed switch

25,

line

20, thence through the rotor system to whichever lamp happens to be paired with lamp 13E at the moment. Suppose it to be K. The circuit to lamp 13E is at this time open at switch 22 so that lamp E is not illuminated but only the lamp corresponding to its enciphered equivalent, namely K. The letter which is thus paired with 13E becomes an authenticator, which will, of course, be duplicated on a machine similarly set to the same key.

Now suppose that the device is being used to authenticate a plain-language message sent from station A to station B. Having transmitted the message, station A operates its device and finds the authenticating letter to be K, for example. This letter is transmitted as the authentication; station B, operating its device, finds that K is correct and hence is warranted in its belief that the message comes from an authorized source. Upon the next authentication, the letter will be dilferent, since one or more of the rotors will have been advanced on the operation of the

plunger

38.

To remove the

rotors

19, cover 27 is opened, latch 34 moved from the upright position of Figure 5 to the horizontal position of Figure 6 which allows

cam

35 to enter the corresponding groove in

stationary cam

36. The compression on the rotor assembly is relieved and, when

pin

30 is removed, the rotors can be readily lifted out. To replace the rotors they are merely set in their approximate positions, pin 30 pushed through wall 26A up to its head 31, and latch 34 raised. In the preferred embodiment, the latch, when lowered, extends beyond the end of wall 26A. It thus prevents the closing of the

rear cover

27. Since the back cover should normally be closed, the feature mentioned serves to assure that the latch will be up and the roto-refiector assembly properly compressed.

The modification of Figure 8 includes a

viewing panel

60, similar in appearance to the viewing panel and

keyboard

14 of Figure 2 and similarly secured to the machine by screws, as 60'. In place of push buttons 18, however, viewing

panel

60 is provided with contacts only, as 61. These contacts, as shown, consist merely of small circular elements of conducting material all connected by a common return wire 12 to the

battery

10. With reference to Figure 7,

contacts

61 may be considered as replacing

switches

17A, 17E, etc. In place of the push buttons 18, a

stylus

62 is provided and this may be considered to be connected to conductor 11 of Figure 7. Encipherment or decipherrnent is accomplished by making contact between

stylus

62 and a desired

contact

61 on

panel

60.

The above description is in specific terms, but it is to be understood that the invention is not limited to the precise structures and circuits shown and described. Instead, for the true scope of the invention, reference should be had to the appended claims.

I claim:

1. In a cryptograph having relatively rotatable electric switches arranged in cascade therein, a plunger arranged for manual operation, means associated with said plunger and cooperating upon depression thereof with one of said electric switches for angularly displacing the same, means associated with said plunger and cooperating upon depression thereof with another electric switch for angularly displacing the same after a predetermined angular displacement of said first mentioned switch, and a brake operable by said plunger through a lost-motion connection for preventing more than a desired angular displacement of any switch.

2. The combination with a cryptographic device having a plurality of electrical inputs for the characters to be enciphered, a plurality of electrical outputs for the enciphered equivalents of said characters, a viewing panel including a lamp for each character, a switch associated with each lamp and with a source of current, and a plurality of circuits each including said source, one of said switches, a lamp associated therewith, an input corresponding to the character represented by said lamp, and a lamp corresponding to the output associated with the last mentioned input, whereby the closing of one of said switches will light a lamp representing a character to be enciphered and a lamp representing the enciphered equivalent of said character.

3. In a keyboard for a device of the character described, a switch for each character which may be utilized, a push button extending through the keyboard and adapted upon depression to close a switch, an indicator for each character which may be utilized, each of said indicators being adjacent to one of said push buttons, and means for connecting said indicators and said switches whereby depression of a push button will energize the indicator adjacent thereto and another indicator to show the enciphered character.

4. In a device of the character described utilizing rotors having ratchet depressions in the periphery thereof and a pawl notch, means for stepping the rotors including a stirrup having a limited rotary movement, means for normally holding said stirrup in an inoperative condition, a plurality of cam-and-pawl devices carried by said stirrup, a cam being adapted for cooperation with a ratchet depression of a rotor and a pawl being adapted for coopera tion with a pawl notch of another rotor, means for moving said stirrup, means dependent upon said movement for causing a cam of a cam-and-pawl device to cooperate with a ratchet depression of a rotor, and means for preventing another cam from cooperating with a ratchet depression of another rotor unless the pawl of said last mentioned cam-and-pawl device is also cooperating with a pawl notch.

5. The invention of claim 4, further characterized by means including detent teeth dependent upon movement of said stirrup for moving into engagement with ratchet depressions of the rotors, thereby to prevent overstepping thereof.

6. The invention of claim 4, further characterized by spring detents adapted to rest in the ratchet depressions of the rotors to inhibit the rotation thereof.

7. In a cryptograph including a source of current, a plurality of indicating devices, a normally open switch for each said indicating device, a plurality of permutable electric paths interconnecting said indicating devices in pairs, and means for permuting said paths, two circuits closable by closing each said switch, one including said source of current, the closed said switch, and the said indicating device thereof, and the other including said source of current, the closed said switch, one of said permutable paths, and the interconnected said indicating device.

8. A cryptograph according to claim 7, further characterized by a manually operable switch, and a further switch having two operable positions interposed in a selected one of said other circuits alternatively to connect in its first position the permutable path of said selected circuit to said normally open switch thereof and in its second position to connect said permutable path of said selected circuit to said manually operable switch, means operable by said permutting means for causing said further switch to assume its said second position thereby to close an authenticator circuit including said source of current, said manually operable switch, said further switch, said permutable path of said selected circuit, and the interconnected said indicating device.

References Cited in the file of this patent UNITED STATES PATENTS 1,096,168 Hebern May 12, 1914 1,657,411 Scherbius Ian. 24, 1928 1,683,072 Hebern Sept. 4, 1928 1,705,641 Korn Mar. 19, 1929 1,733,886 Korn Oct. 29, 1929 1,938,028 Korn Dec. 5, 1933

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Cited By (1)

* Cited by examiner, † Cited by third party

Publication number Priority date Publication date Assignee Title
US8488779B2 (en) 2011-07-25 2013-07-16 Grey Heron Technologies, Llc Method and system for conducting high speed, symmetric stream cipher encryption

Citations (6)

* Cited by examiner, † Cited by third party

Publication number Priority date Publication date Assignee Title
US1096168A (en) * 1912-03-11 1914-05-12 H & H Patent Developing Company Means for interpreting code messages.
US1657411A (en) * 1922-02-11 1928-01-24 Chiffriermaschinen Ag Ciphering machine
US1683072A (en) * 1928-09-04 Electric code machine
US1705641A (en) * 1929-03-19 Permutating device for use in coding machines
US1733886A (en) * 1926-03-20 1929-10-29 Device for coding and decoding
US1938028A (en) * 1928-11-08 1933-12-05 Firm Chiffriermaschinen Ag Electrical coding and de-coding device

Patent Citations (6)

* Cited by examiner, † Cited by third party

Publication number Priority date Publication date Assignee Title
US1683072A (en) * 1928-09-04 Electric code machine
US1705641A (en) * 1929-03-19 Permutating device for use in coding machines
US1096168A (en) * 1912-03-11 1914-05-12 H & H Patent Developing Company Means for interpreting code messages.
US1657411A (en) * 1922-02-11 1928-01-24 Chiffriermaschinen Ag Ciphering machine
US1733886A (en) * 1926-03-20 1929-10-29 Device for coding and decoding
US1938028A (en) * 1928-11-08 1933-12-05 Firm Chiffriermaschinen Ag Electrical coding and de-coding device

Cited By (2)

* Cited by examiner, † Cited by third party

Publication number Priority date Publication date Assignee Title
US8488779B2 (en) 2011-07-25 2013-07-16 Grey Heron Technologies, Llc Method and system for conducting high speed, symmetric stream cipher encryption
US9270462B2 (en) 2011-07-25 2016-02-23 Grey Heron Technologies, Llc Method and system for conducting high speed, symmetric stream cipher encryption

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