Cryptographic Patents

© Brooke Clarke, N6GCE 2003 - 2023



First rotor
                        machine like Enigma 1510441 Electric Coding
                        Machine Sep 30, 1924 E. H. Hebern 1510441
                        Electric Coding Machine Sep 30, 1924 E. H.
                        Hebern

This Hebern machine is the precursor to the Enigma
Patent Classes - USPTO
Table of Patents
    1800
    W.W. I
    1920
    1930
    W.W.II
    1940
    1950
    Korea
    1960
    Vietnam
    1970
    1980
    Berlin Wall
    1990
    2000
    Enigma Related Patents
    Spy satellite
    APX-6 IFF
    Links

Note: This page was made before Google Patents and so most of the links go to the USPTO.  But you can copy the patent number from here and paste it into the Google patent search box.

Patent Classes

In this section when a title is a link it goes to the USPTO web page describing the top class.  There you can see the hierarchy of the classes, that are not so clear below.
When a class number is a link it takes you to a list of all patents in that class.  There are many more listed there than here.
327 - Miscellaneous Active Electrical Nonlinear Devices, Circuits, and Systems
       164 - Generating rectangular (e.g., clock, etc.) or pulse waveform having random characteristic (e.g., random width, etc.)
380 Cryptography
    26 - Having mechanical control of signal encryption (e.g., cam) 119 pats
    27 - By perforated record  77 pats
    28 - Particular Algorithmic Function Encoding 636 pats
            29 - NBS/DES algorithm    257 pats
            30 - Public key   756 pats
    33 - Using plural paths or channels
    37 - Block/data stream enciphering 212 pats
    38 - Frequency shift or inversion 121 pats many speech scramblers here
        39 - Having plural band pass filters  95 pats
    40 - Having plural band pass filters 49 pats
    41 - Having quantizing and subsequent normalizing of signal (e.g., reentry telephone circuitry) 48 pats
    42 - Data stream/substitution enciphering  157 pats
    43 - Key sequence signal combined with data signal  255 pats
    45 - Multiple key level 162 pats
    46 - Nonlinear (e.g., pseudorandom)  487 pats
    47 - Plural generators  155 pats
    51 - Having production of printed copy (e.g., printer, typewriter)
    52 - Including particular structure or housing (e.g., display, keyboard)
    54 - By Modifying Optical Image (e.g., Transmissive Overlay) 322 pats
    55 - Having Production of Printed Copy (e.g., Cryptographic Printer or Typewriter)  161 pats
    56 - Selectively Movable Element having Code Characters  47 pats
            57 - Rotatable  54 pats
            58 - Characters on peripheral surface (e.g., cylinder section)  32 pats
    252 - Electrical Signal Masking  135 pats
            253 - By signal having discrete frequency component  50 pats
            254 - By signal having discrete step amplitude variation  33 pats
    255 - Communication System using Cryptography   169 pats
           260 - Symmetric key synchronization  125 pats
            262 - Transmitting a seed, sequence, or initial value  179 pats
            265 - Combining outputs of shift register  76 pats
            274 - Synchronization  100 pats
            275 - Speech scrambler detail  97 pats
            277 -
  280 -
            284 -
400 Typewriting Machines
       89 - Key Reassignment
               90 - Electrically powered
708 Electrical Computers: Arithmetic Processing and Calculating
          100  Electrical Digital Calculating Computer
                  250 - Random number generation 289 patents

713 Electrical Computers and Digital Processing Systems: Support
       150 - Multiple Computer Communication using Cryptography 166 pats
               151 - Protection at a particular protocol layer  99 pats
               169 - Mutual entity authentication  147 pats
               171 - Having key exchange  215 pats
               181 - Message digest travels with message 142 pats

1800

251292 Telephony, J. H. Rogers, 1881-12-20, - "My invention consists in throwing a message sent from any transmitting-instrument through two or more circuits alternately in rapid succession."
253061 Apparatus for Preparing and Transmitting Secret Telegraphic Messages Jan 31 1832 A F & F B Johnson  178/92; 83/202; 178/4; 178/17R; 178/37; 380/26 - intentions on paper tape rather than printed characters.  Precursor to punched paper tape.  Little security since a skilled person could read the code.
420262 Mixer 366/247; 210/251; 210/466; 220/568; 222/192; 380/54 - beverage mixer
449723 Device for Forming and Deciphering Secret Communications, Marshall A. Wier, 1891-04-07, - “bi-letter code,'
1086823 Cryptographic Attachment for Type Writing Machine, E.H. Hebern & F. Hoffman, Feb 10, 1914, 400/89; 400/473 -
1210656 Apparatus for Coding and Decoding Jan 2, 1917 S M Kintner 380/26; 380/51; 400/77 - fixed substitution alphabet for teletype type machines
1233035 Apparatus for Producing a Series of Signs, A.G. Damm, Jul 10 1917, 380/58 - A-21 ?
1244477 Telegraphy Oct 30, 1917 P.B. Delany 380/255; 178/98; 380/38 a public sounder with inverted signals to prevent listening to message
1310719 Secret Signaling System, G.S. Vernam, July 22, 1919, 380/33 ; 380/259; 380/26
Class 380/33 is for crypto systems that transmit the message using a plurality of paths, yet that's not how it works.  This is just a One Time Pad.
1312572 Secret Signaling System Aug 12 1919 380/43; 380/260 R D Parker - Morse code is broken up using a distributor
1320908 Ciphering and Decyphering Mechanism Nov 4, 1919 380/27 R. D. Parker - paper tape

    W.W. I 1914 - 1911 (Wiki)

1920

1356546 Cyphering System Oct 26, 1920 380/47 L F Morehouse (AT&T)- Two 5 level paper tapes
1138832 Writing-machine, Ottomar Fedor Bamberg, Edmund Weinhold, App: 1913-05-29, Pub: 1915-05-11, oldest patent with the main classification of 380/51 - single wheel simple substitution 32 position rotor machine for encrypting.
1414496 Cryptographic Typewriter May 2 1922 P G G Beyer 380/51; 400/71; 400/184 - single rotor turns one step with each key press
1415106 Cyphering Device May 9 1922 380/27; 380/51; 380/267 L F Morehouse (AT&T) - improves on 1320908 by not encyphiring the control characters, makes for a legible printout
1416765 Cyphering Device May 23 1922 380/27 G S Vernam (AT&T) - filed Jan 1920, paper tape
1426699  Cyphering Device Aug 22, 1922 380/27 R E Pierce (AT&T) - paper tape
1484477 Apparatus for Ciphering and Deciphering Code Expressions, A.G. Damm, Feb 19 1924, 380/55 ; 101/486; 101/85
1491358 G Enciphering Machine April 22, 1924 WE 380/27; 380/51; 400/73; 400/90 paper tape
1510441 Electric Coding Machine Sep 30, 1924 E. H. Hebern 380/51; 400/77
Photo on Jerry's page.  Wiki: Hebern_rotor_machine
1515680 Coding and
                decoding machine, Henkels Albert, 1924-11-18
1515680 Coding and decoding machine, Henkels Albert, 1924-11-18, 380/57 -
1516180 Secret Signaling System Employing Apparatus for Automatically Encyphering and Decyphering Messages Nov 18, 1924  380/27; 380/47 W. F. Friedman - paper tape
1520089 Electric Typewriting Machine, A. Scherbius (Wiki), Dec 23 1924, 400/45 ; 101/94; 400/155; 400/163.2 - motor powered typewriter
1522044 Secret Communication System June 6, 1925 R. Brown - speech frequency inversion 380/38
1522775  Secret Signaling System Employing Apparatus for Automatically Encyphering and Decyphering Messages Jan 13, 1925 380/27; 380/47 W. F. Friedman - paper tape
1523689 Coding and Decoding Machine, S Hole, Jan 20, 1925, 380/55 ; 235/201ME; 400/181; 400/77

1533252 Coding and Decoding Machine H.A. Koch, Apr
                14, 1925
1533252 Coding and Decoding Machine H.A. Koch (Wiki), App: 1920-09-18, Pub: Apr 14, 1925 - pneumatic  380/51 ; 400/176

Patent office markups probably because of a legal challenge.
This patent filed after Scherbius 1556964

1540107 Apparatus for the Production of Cipher Documents especially for Telegraphic Dispatch AG Damm 380/52 ; 400/474; 400/77
1542567 Secret Signaling June 16, 1925 R.C. Mathes voice frequency subbands & multiple channels 380/34; 380/38

1556964 Electric
                Ciphering Apparatus, A. Scherbius, Oct 13 1925
1556964 Electric Ciphering Apparatus, A. Scherbius (Wiki), App: 1922-04-20, Pub: Oct 13 1925, 380/51 - Start of Enigma (Wiki)
Class 380: Cryptography
51: Electric Signal Modification\Having production of printed copy

1584660 Ciphering Device, A. Scherbius, May 11 1926, 380/51 ; 400/158; 400/259; 400/261 - cited by Link 2435502 Radio signaling means for aviation trainers - basis of Enigma
1633625 Sycercy System June 28 1927  380/28 (AT&T) - telephone scrambler using controlled distortion
1643546 Apparatus for Deciphering Cipher Messages, A.G. Damm, Sep 27 1927
1644239 Apparatus for Producing a Series of Signs Damm Oct 4, 1927 380/58 - A-21?

Enigma

1657411 Ciphering Machine, A. Scherbius, Jan 24 1928, 380/52 ; 234/96; 380/261; 380/267; 380/51
1657411 Ciphering
                Machine, A. Scherbius, Jan 24 1928, 380/52 ; 234/96;
                380/261; 380/267; 380/51


patent 001683072
1683072 Electric Code Machine E. H. Hebern, Sep 4, 1928  380/52; 341/2; 380/58 (pre enigma) rotors, keyboard and lights - Friedman showed this was not secure (Wiki)
The machine shown on Jerry's page may be a prototype of this one?
1684028 Coding and Decoding Apparatus and Code Changing Device Therefore, S Hole, Sep 11, 1928, 380/26 ; 380/51; 400/182; 400/71
1724163  400/365; 181/201; 400/90; 400/689; 400/690 quiet electric typewriter
1726578 - Secret Telephone System - Sep 23, 1929 Harry Nyquist - add a time delay proportional to frequency to make unintelligible

1930

1744347 Coding Machine Kryha Jan 21, 1930 380/57 ; 380/58
1777425 Electric cipher-writing machine, Bernstein Paul, Chiffriermaschinen, 1930-10-07, - period of a single rotor much longer than 26 steps
1834278 Device for Insuring Privacy of Reception of Printing Telegraph, Parker Hitt (International Communications Labs), Dec 1 1931, 178/37 ; 178/42
Just conceals the printing on the paper strip from the delivery boy by rolling it up.
1846105 Ciphering Apparatus Hagelin Feb 1932 380/55 - Model B-21
1848291 Ciphering and Deciphering Apparatus, Parker Hitt (International Communication Labs), Mar 8 1932, 380/26 ; 370/298; 380/51 - printing telegraph
1861857 Cryptographic Machine, E.H. Hebern (International Code Machine Co), Jun 7 1932, 400/90 ; 400/217; 400/33; 400/364; 400/422; 400/615.2; 400/621; 400/621.1; 400/685; 400/691; 400/88
closer to Enigma
1952246 Arrangement for the Feeding of Gaseous Tubes, Hagelin, Mar 27 1934, 315/256 ; 315/228 - Lighting or crypto? - a shunt on a transformer serves to limit lamp current
1938028 Electrical
                coding and de-coding device, Korn Willi,
                Chiffriermaschinen, 1933-12-05
1938028 Electrical coding and de-coding device, Korn Willi, Chiffriermaschinen, 1933-12-05, 380/26 - has the feel of the M-209?, bit the title includes "electrical"

"
The device according to the present invention, in the event of an error at any point in the coding or decoding, enables the device to be re turned immediately in a simple manner to the condition and to that position of the device at which the error must occur, so that it is only necessary to take up the coding or decoding operation afresh from there, without it being necessary to begin all over again from the start."

1953918 Cryptographic System and Apparatus April 10, 1934 J.I. Bellamy 380/42 instead of a digraphic cipher, 4 letters are automatically used
1956384 Pocket Cryptographic Apparatus, April 24, 1934,  A. Gentet 380/56 -aka the Sphinx strip cipher device.
1984599 Educational Device Safar Dec 1934 434/228 ; 315/313; 340/332
2013671 Electrical System and Apparatus  for Transmitting Intelligence Sep 10, 1935
2028508 Ciphering Apparatus, Parker Hitt (International Communication Labs), Jan 21 1936, 380/55 ; 400/478- typewriter that automatically spaces 5 letter groups
2028772 Cryptographic System Jan 28, 1936 Friedman 380/26 ; 380/51 - rotors
2042116 Mechanical Movement, R.K. Morris, May 1926, 74/143 ; 235/91R; 74/144; 74/151; 74/153 - Veeder patented his counter in 1899 so that was a common technology
2056284 Signaling Means and Apparatus Oct 6, 1936 LeRoy A. MacColl 380/252; 178/63R; 178/69B; 307/106; 380/46 paper tape
2089603 Ciphering Machine Hagelin Aug 1937 380/55 ; 380/58; 400/162; 400/83; 400/88 - model C-35 first in the C series which resulted in the M-209
2098956 Signaling System Dudley, Nov 16, 1937 380/36 ; 379/414; 704/205 - multiple circuit split frequency
2116683 Coding and Decoding Machine WS Lemmon  380/55 ; 400/373; 400/474; 400/477 -
2116731 Coding and Decoding Machine AR Noll  380/55 ; 400/474; 400/478; 400/479; 400/77
2125995 Ciphering Machine R.W. Doidge Aug 9, 1938 380/26
2139676 Cryptographic Apparatus Friedman Dec 1938 380/26 - Enigma like
2140424 Cryptographic Device Friedman Dec 13 1938 380/57 - 29 tooth gear meshing with 40 tooth gear
2151091 Signal Tansmission H.W. Dudley March 21, 1939 (filed 1935) 380/39; 84/701; 84/DIG11; 324/76.12; 324/76.29; 379/414; 704/205; 704/206; 704/209 - a vocoder used to compress speech to about 500 Hz bandwidth - a precursor to SIGSALY
2183248 Wave Translation, RR Riesz, Dec 12, 1939 381/61 ; 333/28R; 380/39; 472/64; 704/205 - also see 3012098

1939 - 1945 W.W. II (Wiki)

1940

2206590 Portable Transmissin System, Webb Jr., Jul 2, 1940 - simple speech inverter
2291978 Radio transmission system, Mouradian Hughes, 1942-08-04, - adds channels on top of AM modulated transmissions, either to get more channels or for secrecy
2327248 Wave-signal translating channel, Nelson P Case, Hazeltine Corp, App: 1942-05-08, W.W.II, Pub: 1943-08-17, - IFF?
2330049 Positive Detent, Hagelin, Sep 21 1943, 192/215 - random step seize
2373890 Cipher Machine E. H. Hebern April 17, 1945 380/51; 400/77; 400/473; 400/474
2394765 Ciphering and Deciphering Mechanism, Hagelin, Feb 12 1946, 380/26
2398694 Carrier-wave generating system, Nelson P Case, Hazeltine Corp, - generating correct frequency for given channel, IFF?
2401402 Secret Communication System 380/28 - June 4, 1946 (RCA) - voice by using a record (or photographic image) as a key
2402059 Secrecy communication system, James F Craib, Hazeltine Research, App: 1942-04-29, W.W.II, Pub: 1946-06-11, - voice
2402182 Rotor, L. Rosen  Jan 18, 1946  L. Rosen 380/26; 380/33; 380/58 - contact pressure is relieved during rotation to minimize wear
2413440 Electronic switch, John F Farrington, Hazeltine Research, App: 1942-05-15, W.W.II, Pub: 1946-12-31, - IFF?
2413451 Ultra high frequency tuning unit, Johnson John Kelly, Hazeltine Research, App:1942-10-03, W.W.II, Pub: 1946-12-31, - IFF?
2426454 Electronic switch, Johnson John Kelly, Hazeltine Research, App: 1942-05-27, W.W.II, Pub: 1947-08-26, - IFF? pulse train with variable widths
2437255 Graphic Privacy System March 9 1948 J V L Hogan 380/54; 355/42; 355/52; 380/37; 380/243; 380/245
2247170 Ciphering Machine Hagelin June 1941 380/55 ; 400/162; 400/89 - model BC-38 based on the C-38
2265715 Cipher Apparatus H. S. Bacon Dec 9, 1941 380/27; 400/90
2406031 Telegraph ciphering key tape machine, Parker Ralzemond D, Bell Telephone Labor Inc, Aug 20, 1946, 380/26, 380/44, 250/223.00R, 250/230, 234/96 - uses transparent and opaque balls fed from hopper. punch 5-level tape
2411206 Electrical Signalling Method, Guanella, Nov 19, 1946 380/39 ; 380/38 - Original permuting sub bands, but they can have different bandwidths

1950

1950 - 1953 Korean conflict (aka Police Action) (Wiki)

2510338 Means of and Method for Scrambling Speech Signals, Guanella, Jun 6, 1950 380/39 - sub bands enhanced
2513307 Coding Means and Method, R.E. Gilman (IBM), Jul 4 1950, 380/26 - a group of plain text characters is converted into a group of cipher text characters (block cipher) pre DES
Calls:
    50946 Improvement in Signals, Albert J. Myer, Nov 14 1865, 380/57- Cipher Disk
1510441 Electric Coding Machine Sep 30, 1924 E. H. Hebern 380/51; 400/77
1683072 Electric Code Machine E. H. Hebern, Sep 4, 1928  380/52; 341/2; 380/58 (pre enigma rotor machine)
1953829 Apparatus for Cryptographically Transposing Characters, R.K. Morris, Apr 3 1934, 380/55 ; 200/11A; 439/49; 74/142
2413592 Coding and Decoding Chart for Cryptography, Charles B. Strother, Dec 1946, - sliding strips
2425518 Ciphering Apparatus, C.R. Doty (IBM), Aug 12 1947, 380/27 ; 400/330.3; 400/373; 400/474; 400/477; 400/71
2518458 Authenticating Device, W.F. Friedman, Aug 15 1950, 380/59 - 10 Enigma type drums
2530579 Speech Inverter, L Koros, Nov 21, 1950  380/39 ; 332/153; 332/155
2547515 Secrecy System, W.J. Zenner (Teletype), Apr 3 1951, - uses Hebern drums, but blocks reversals, i.e. if A->Y then Y does not go to A.
Calls:
1310719 Secret Signaling System, G.S. Vernam, July 22, 1919, 380/33 ; 380/259; 380/26
1522775  Secret Signaling System Employing Apparatus for Automatically Encyphering and Decyphering Messages Jan 13, 1925 380/27; 380/47 W. F. Friedman - paper tape
2405569 Cryptographic Telegraph System, K.E. Fitch (Bell), Aug 13 1946, 380/27 ; 380/43- 5 level TTY
2406829 Telegraph System, H.H. Haglund (WU), Sep 3 1946, 380/43
2629017 Speech Transmission System, Dahlbom, Feb 17, 1953 370/503 ; 327/418; 380/39 - uses VOCODER
2709218 Method and Means for Anti-Jamming in Radio, Gabrilovitch, May 24, 1955 455/45 ; 380/39; 455/1; 455/196.1; 455/48; 455/63.1
2765364 Keying Mechanism Hagelin Oct 1956 380/59 ; 380/55; 400/478; 400/89 - experimental model C-36
2802047 Electric Switching Device for Ciphering Apparatus, Hagelin, Aug 6 1957, 380/26 ; 380/51; 400/89 - looks like KL-7
Talks about teleprinters and the need to NOT encipher the <CR> and <LF> but do cipher <Fig> and <Chr> also talks about "telegraph impulse system (Wiki Baudot) and multicircuit systems (one wire per character).
Calls:
1683072 Electric Code Machine E. H. Hebern, Sep 4, 1928  380/52; 341/2; 380/58 (pre enigma rotor machine)
2402182 Rotor, L Rosen,   Jan 18, 1946  L. Rosen 380/26; 380/33; 380/58 - more reliable rotor construction
Called by:
2917579 Ciphering Machines, Hagelin, Dec 15 1959, 380/26 ; 341/78; 341/81
3214518 APPARATUS FOR CODING AND DECODING TELEPRINTER MESSAGES, Fritz Butzke  (Siemens & Halske), Oct 26 1965, -
Reads input tape in two positions seperated by n characters and combines them into a single output character.  That output character is combined with a key tape character to generate the final output.
3657699 Programmable cryptic device for enciphering and deciphering data, Harold S. Richard et al (NCR), Jan 18 1977 - aimed at credit cards and ATMs
4275265 Complete substitution permutation enciphering and deciphering circuit, George I. Davida et al - allows for a 128 bit key and certainty that all circuits are complete -
an upgraded DES type cipher
2802047 Fig1
                KL-7?
2802047
                Fig2.gif
2802047 Fig3
2802047 Fig4
2802047 Fig5


2851794 Cryptographic Coding and Decoding Apparatus, B. C. W. Hagelin Sep 15, 1968 380/57 - Crypto AG CD-55 first of the pocket machines


patent 2851794

2855514 Gaseous Discharge R.F. Noise Source Oct , 1958 331/78; 313/633; 327/164; 327/601; 333/24R (up to 4.5 GHz)
2877565 Electrical Cryptograph, Friedman (M-325 Wiki: SIGFOY)  380/52 - using a reflector made it weak.
2896071 Security Communication System, July 21, 1959 380/39 ; 341/173; 380/260; 380/275 - synch signal embedded in message
2917579 Ciphering Machines, Hagelin, Dec 15 1959, 380/26 ; 341/78; 341/81 -
Calls:
1652708 Permutation Switch, Leeuw, Dec 13 1927, 439/189 ; 200/42.02; 439/488
1663624 Electric Apparatus, A.G. Damm, Mar 27 1028, 380/26
Calls:
1502376 Production of Ciphers, A.G. Damm, Jul 22 1924, 380/52 ; 400/474; 400/77 -
1540107 Apparatus for the Production of Cipher Documents Especially for Telegraphic Dispatch, A.G. Damm, Jun 2 1925, 380/52 ; 400/474; 400/77

1905593 Coding Machine, Willi Korn, Apr 25 1933
1905593 Coding Machine, Willi Korn, Apr 25 1933, 380/26

Has the feel of the M-209 but the rotors work like an Enigma with electrical contacts.

1953829 Apparatus for Cryptographically Transposing Characters, R.K. Morris, Apr 3 1934, 380/55 ; 200/11A; 439/49; 74/142
2529487 Rotor Assembly, V.E. Cooley, Nov 14 1950, 380/26 ; 200/9
2753034 Coding Machine, R. Hell, Jul 3 1956, 380/27 ; 380/51
2777556 Power-Driven Ciphering Devices, Hagelin, Jan 15 1957, 380/51
2802047 Electric Switching Device for Ciphering Apparatus, Hagelin, Aug 6 1957, 380/26 ; 380/51; 400/89

1960

1961 - 1975 Vietnam era (Wiki)

2934833 Enciphering Device, F. Burkhard, May 3 1960, 380/26
2941036 Electrical Signal Scrambling and Unscrambling Apparatus, W. Honolka,
3006081 Encoding Keying Device Nyberg Oct 31, 1961 380/59 ; 380/57
3046545  Rapid Correlation Echo Ranging System July 24, 1962 342/189; 342/195; 367/100; 370/521 - Pseudo Random Generator
3083263 Auxiliary Apparatus for Teletypers, Hagelin, Mar 26 1963, 380/2 ; 380/33- CCIT 2
3124748 Secret Signaling Systems Mar 10, 1964, 380/32 ; 380/34; 380/39 mixing voice bands with changing oscillator
3163809 Random Noise system for Vibration Testing Dec 29, 1964 318/132; 73/579; 327/164; 330/103; 330/126; 331/78 Photomultiplier generates noise and a lamp is used in the feedback circuit
3171089 Diode Random Noise Generator Feb 23, 1965 331/78; 327/164; 327/584 avalanche diode in reverse breakdown
3204035 - 370/208; 375/362 Orthonormal Pulse Multiplex Transmissions Systems 26 Nov 1962
3328526 Speech Privacy System Schroeder, Jun 27, 1967 380/39 ; 369/26.01; 455/39 - uses the sub band amplitudes to modulate the phase of that freq.  all the subbands are send at equal amplitude. see Dudley vocoder 2151091
3349882 Ciphering Machine Florin et al Oct 31, 1967 380/57 ; 400/162 - M209 like
3439279 - Synchronizing System for Random Sequence Pulse Generators April 15, 1969
3485948 Perforated Tape Accessory Apparatus for a Ciphering Machine, Hagelin, Dec 23 1969, 380/27 ; 341/95
3490044 Communications System, Roger L. Easton, 1968-11-05, 380/34; 455/59 -

1970

3614316  Secure Communication System Oct 17, 1971 (filed 1964) Secretary of the Navy 380/47; 375/150; 380/34; 380/46
An improved secure communication system comprising: A first and a second pseudorandom noise generator, said generators having,respectively, a first and a second shift register, each register having N stages and having logical circuit means for randomly recirculating binary bits through the register for generating a random repeatable pattern of binary bits, A reset pulse source coupled to all stages of said first register to reset said first register to a predetermined starting binary number, A starting point switch matrix comprising N logical zero-one switches connected, respectively, between the stages of said second register and said reset pulse source, Means for feeding a binary information number to said switches to reset said second register to a starting point a predetermined number different from the starting binary number of said first register, Transmitting means for transmitting said pseudorandom noise generators outputs connected to the outputs of said pseudorandom noise generators; Receiving means for receiving said transmitting means transmissions, said receiving means having an output; Recycling storage means connected to the output of said receiving means for storing the receiving means output signals; A third pseudorandom noise generator identical in sequence to said first and second pseudorandom noise generators having an output and a reset input, said receiving means output connected to said reset input; A correlator having a first input connected to said storage means and a second input connected to said third pseudorandom noise generator output for generating a signal upon correlation of said storage means output and said third pseudorandom noise generator output, and; Timing means connected to said correlator for timing the interval between outputs thereof.  Relates to SONAR.
3618077  Walsh Function Generator - Nov 2, 1971
3639690 Digital Privacy System - Feb 1, 1972 Motorola
3651404 Voice Privacy Adapter - March 21, 1972 frequency inversion - Motorola 380/39 ; 332/168
3678204 - 177/15; 370/209 Signal Processing and Transmission by means of Walsh Functions 26 Oct 1970 ITT
3701143  Walsh Function Generator -
3723878 Voice Privacy Device, Miller, Mar 27, 1973 380/39 ; 380/275; 380/44 - additions to inverter
3742201 - 708/410 Transformer System for Orthogonal Digital Waveforms June 26, 1973
3746799  Method and Apparatus for Encoding and Decoding Analog Signals -
3749832 Binary Coded Signal and Ciphering and Deciphering Method and Systems Embodying Same July 31 1973  380/28; 341/95; 380/37
3766316 Frame Synchronization Detector -
3777064 Voice Privacy System, US Navy, Dec 4, 1973 380/39 - uses active RC low pass filters instead of LC or active LC filters.  uses "Weaver modulator"
3781472 Digital Data Ciphering Technique, G.E. Goode (Datotek), Dec 25 1973, - electronic TTY
3781473 Random Digital Code Generator, G.E. Goode (Datotek), Dec 25 1973, 380/46 - electronic TTY
3784983 Information handling system, J Eckert, H Welsh, J Weiner, R Shaw, Sperry Corp, App: 1952-03-31 (22 Year Delay), Pub: 1974-01-08, 263 sheets of figures! Tubes,
3795864 - Methods and Apparatus for Generating Walsh Functions -
3798359 (Lucifer) Block Cipher Cryptographic System 380/37 ; 380/28; 380/29; 380/46
3808536 Communications Scrambler System 380/45; 375/141; 380/46; 380/47- A scrambler system in which amplitude zero-crossings in speech are encrypted at a transmitter by combination with a pseudo-random digital sequence, the reverse process occurring at the receiver. The amplitude envelope need not be encrypted, but if desired, can be encrypted by combination with a further pseudo-random digital sequence. A higher level of scrambling can be achieved in the transmitted signal by using the conjugate of the amplitude envelope.  With a sequence bit rate of about two kilobits per second, there is no increase in bandwidth requirements compared to the transmission of unscrambled speech. Thus standard transceivers can be employed, and pre-existing ones readily modified for scrambling and unscrambling.
3859515 - 708/410; 324/76.12; 324/76.21; 340/5.81; 382/121 Method and Apparatus for Signal Spectrum Analysis by Hadamard Transform Jan 7 1975 Burroughs
3886313 Voice security method and system Datotek, May 27, 1975 380/40 ; 341/181; 380/39
3893031 Synchronization System for Voice Privacy Unit filed Nov 8, 1972 granted July 1, 1975 Henry L. Majeau, Boeing Company, 380/274; 340/146.2; 380/44; 380/262; 380/275 - uses 3 tones for synchronization like the KY-57 - A system for synchronizing the operation of two or more voice privacy units. At least one otherwise "clear" tone is modulated by a statistically random signal known as a Barker word, this tone then being mixed with the audio signals and transmitted. The modulation is present for a very short time, the conclusion of the modulation initiating the operation of a code generator which scrambles the succeeding audio signals. The recognition of the reception of the modulated tone at the receiver initiates the operation of its code generator (at the conclusion of the modulation), thereby recovering the original plaintext speech.  This is a form of speech inversion
3909534 Voice privacy unit for intercommunication systems -
3920894 Pseudo-Random Parallel Word Generator
3934078 Key Generating System, D.K. Gannett (Bell Labs), Jan 20 1976 (Filed May 1 1946) , 380/47 ; 331/78; 380/41 - SIGSALY?
3936748
Secret communication system employing magnetic control of signal, Hans A. Bomke (Army), Feb 3 1976 (filed: Sep 10 1956), 380/59 ; 359/281; 398/183 - Faraday effect
Optical or microwave signal has polarization plane rotated
3936749 Matched filter communication systems, Ernst A. Guillemin (Army), Feb 3 1976 (filed: Jun 23 1961), 375/260 ; 375/240; 375/270; 375/343; 380/34; 380/40 - SSB signal
3937888 Signal transmission with secrecy, Oscar Myers (Bell Labs), Feb 10 1976 (filed Jun 17 1943), 380/22 ; 380/35 - select one of 6 time delays for voice signal
3944744  Matrix Coding Secret Signaling System, D.K. Gannett (Bell Labs), Mar 16 1976 (filed: May 10 1945), 380/41 - SIGSALY?
3944745  Secret signaling system with means for preventing key Disclosure, Danforth K. Gannett (Bell Labs), Mar 16 1976 (filed: May 10 1945), 380/41 - SIGSALY?
3962539 (DES) Product block cipher system for data security 380/29 ; 380/37; 713/150
3965296  Signaling System, R.L. Miller (Bell Labs), Jun 22 1976 (filed: Jun 30 1944), 380/41- SIGSALY?
3965297
  Secret communication signal generating system, D.K. Gannett (Bell Labs), Jun 22 1976 (filed: May 1 1946, 380/41 ; 331/78 - SIGSALY?
3967067 Secret telephony Filed: Sep 24, 1941 Pat Date June 29, 1976 380/41; 380/40; 704/205 Part of the SIGSALY W.W. II Voice system
3968454 Signaling circuit, A.J. Busch (Bell Labs), Jun 6 1976 (filed: Sep 27 1944), 331/78 ; 380/41; 380/47 - 17, 14, 13 stages TTY?
3976839 Telephone privacy system, R.L. Miller stem for data security 380/29 ; 380/37; 713/150
3965296  Signaling System, R.L. Miller (Bell Labs), Aug 24 1976 (filed: Jun 30 1944), 380/41 ; 370/500 - SIGSALY?
3979558 Signaling system, E. Peterson (Bell Labs), Sep 7 1976 (filed: Jun 30 1944), 380/41- SIGSALY?
3983326 Key pulse generator for secrecy signaling circuit, Sep 28 1976 (filed: Sep 27 1944), 380/41 ; 331/78 - SIGSALY?
3983327 Electrical signaling, D.K. Gannett (Bell Labs), Sep 28 1976 (filed: Jul 9 1945), 380/41 - SIGSALY?
3984922 Rotors, Leo Rosen, Oct 12 1976, 380/26
3985958 Secret telephony Filed: Dec 18, 1941 Pat: Oct 12, 1976 Part of the SIGSALY W.W. II Voice system
3991271 Voice security method and system - analog
3991273 Speech component coded multiplex carrier wave transmission Filed: October 4, 1943 Pat: Nov 9, 1976 Part of the SIGSALY W.W. II Voice system
3995115 Speech privacy system Bell Labs Nov 30, 1976 380/32 ; 380/275; 380/39; 704/205 Vocoder & removing fund freq
4013837 Voice security method and system - analog
4020285 Voice security method and system - analog
4052565 - Walsh function signal scrambler, D.D. Baxter (Martin Marietta), Oct 4 1977, 380/28 ; 370/503; 375/142; 375/238; 375/242; 375/353; 375/367; 380/275; 380/31; 708/410
4079188 Multi-mode digital enciphering system
4115657 Random digital code generator - digital multiple registers with relativity prime lengths
4126761 Method of and means for processing an audio frequency signal to conceal intelligibility -
4133973 Digital cryptographic system having synchronous and asynchronous capabilities
4133974 System for locally enciphering prime data - digital key generator using a register and addressable memory
4140873 Multi-mode digital enciphering system 
4145568 Method and apparatus for ciphering and deciphering messages 380/47; 380/44; 380/260; 380/277 Pat: March 20, 1979 Filed: October 6, 1964
4145569 Method and apparatus for synchronizing the ciphering and deciphering of binary-coded messages 380/262; 380/47 Pat: March 20, 1979 Filed: December 22, 1964
4149035 Method and apparatus for enciphering and deciphering audio information  -
4154006 Coding and decoding machine Wood; Chester C, May 15, 1979 380/57 ; 341/2 -
patent 4155659

Searcing for more patents related to 4154006
4143978 Electro-mechanical cipher machine, Bern Anderson, Donald W. Seiler, Navy, 1979-03-13, -
6175625 Control circuits for electric coding machines, Laurance F. Safford, Donald W. Seiler, NSA, App: 1944-12-15, TOP SECRET 57 Years; Pub: 2001-01-16, (see below)

4155659 Printing and coding machine, Edward S. Larson, Carl A. Levin, Rolf A. Thienemann (Navy), May 22 1979 (filed: Feb 5 1940), 380/55 - SIGABA?
4156314 Rotors for a ciphering machine 380/26; 380/51; 439/43 Pat: May 29, 1979 Filed: February 21, 1944 Rosen; Leo 26 contacts
       not KL-7 and not used in any U.S. crypto machine
4157453 Cryptographic telegram transmission system 380/36 Pat: June 5, 1979 Filed: October 10, 1944 Rosen; Leo
4157454 Method and system for machine enciphering and deciphering June 5, 1979 380/37; 380/42; 380/45 (IBM) -
4166922 Multi-mode digital enciphering system with repeated priming sequences
4168395 Start/stop teleprinter scrambler 380/35; 380/43
4167700 Digital voice protection system and method -
4169212 Multi-mode digital enciphering system
4170714 Digital cryptographic system and testing thereof - digital data
4172968 Electrical system 380/43; 380/261; 380/275 digital voice encryption
4176316 Secure single sideband communication system using modulated noise subcarrier 380/34

1980

       Berlin Wall 1961 - 1989 (Wiki)

4183088 Random number generator 708/250; 331/78
4184117 Communication security method and system 380/34; 380/35; 455/46
4185166 Multi-mode digital enciphering system - digital: off line, asynchronous or synchronous data
4185928 Printer for electric coding machines 380/55
4188580 - Secure communication system-  380/254; 375/145
4195202 Voice privacy system with amplitude masking -
4200770 - (Public Key) Cryptographic apparatus and method April 29, 1980 380/30; 380/44; 380/285; 713/169; 713/171
4217469 - Coding and decoding apparatus for the protection of communication secrecy 380/27; 380/36 time delay
4218582 (Trapdoor flawed)Public key cryptographic apparatus and method 380/30 ; 713/168; 713/170
4229817 Portable electronic cryptographic device - alpha numeric digital keypad & display
4232194 Voice encryption system, Adams, Nov 4, 1980 380/28 ; 380/257; 380/275; 380/39; 704/205 - using DSP methods to provide more sub bands
4244053 Privacy communication method and system -
4245346 Communication system, Robert J. Grady, Harry G. Posthumus, Magnavox Electronic Systems Co, Filed: 1962-02-07, (Classified) Pub: 1981-01-13, 380/31; 342/378 - Direct Sequence Spread Spectrum.
4268720 Scrambler speech transmission and synchronization system -
4276652 Secure communication system with improved frequency-hopping arrangement - variable BFO
4278840 Dynamic frequency and time voice encryption system and method - analog
4309569 (tree authentication) Method of providing digital signatures 713/177 ; 340/5.8; 713/180; 902/2; 902/5
4316055 - Stream/block cipher cryptographic system February 16, 1982 380/37; 380/43; 380/45
4341925 - Random digital encryption secure communication system - combine two PR code streams
4349695 Recipient and message authentication method and system - two way pass & CRC at end
4351982 RSA Public-key data encryption system having large random prime number generating microprocessor or the like September 28, 1982 380/30; 380/282; 380/285 (Racal-Miglo Datacryptor64)
4358857 Communication system, Joseph P. Gleason, Harry G. Posthumus, Magnavox, App: 1958-05-09, TOP SECRET, Pub: 1982-11-09, -
4386233 Cryptographic key notarization methods and apparatus 380/281 ; 380/280; 380/45; 713/155; 713/180; 902/2; 902/5
4392021 Secure facsimile transmission system using time-delay modulation - FAX
4405829 (RSA) Cryptographic communications system and method Sep 20, 1983 380/30; 380/255; 713/150; 713/151 (Racal-Miglo Datacryptor64)
4424414 Exponentiation cryptographic apparatus and method 380/30 ; 380/285; 380/44; 713/171
4433211 Privacy communication system employing time/frequency transformation
4434322 Coded data transmission system Feb 28, 1984 380/43; 380/44; 380/265 (Racal-Miglo Datacryptor64)
4567600 Method and apparatus for maintaining the privacy of digital messages conveyed by public transmission 713/174 ; 380/278; 380/285; 380/33
4625076 (ESIGN signatures) Signed document transmission system 713/176 ; 380/30; 713/180
4633036 (Prime 3 Gen)Method and apparatus for use in public-key data encryption system 380/30 ; 380/277; 902/2
4748668 Method, apparatus and article for identification and signature 380/30 ; 380/28
4754482 Method and apparatus for synchronizing encrypting and decrypting systems June 28, 1988 713/181; 380/262; 714/798
4850017 Controlled use of cryptographic keys via generating station established control values 380/280 ; 380/281; 380/45; 380/47
4850019 Data randomization equipment 380/29 ; 380/33; 380/37; 380/46
4856063 No-overhead synchronization for cryptographic systems August 8, 1989 380/262- Datotek

1990

4881264 Digital signature system and method based on a conventional encryption function 713/177 ; 380/28; 713/180
4893339 Secure communication system January 9, 1990
4908861 Data authentication using modification detection codes based on a public one way encryption function 713/187 ; 340/5.8; 380/29; 380/30; 726/2
4956863 Cryptographic method and apparatus for public key exchange with authentication 380/30 ; 380/285; 380/44; 380/47; 713/169; 713/171
4995082 Method for identifying subscribers and for generating and verifying electronic signatures in a data exchange system 713/169 ; 380/30; 380/46; 705/67; 713/180
5003597 Method and apparatus for data encryption 380/37 ; 380/28; 380/29
5003599 In-band framing method and apparatus
5016274 On-line/off-line digital signing 705/66 ; 235/379; 235/380; 340/5.4; 380/29; 380/30; 713/180
5140634 Method and apparatus for authenticating accreditations and for authenticating and signing messages 713/180 ; 235/382; 380/30; 705/67; 713/172
5146498 Remote key manipulations for over-the-air re-keying - based on modifying the current stored key to make the new one
5214703 Device for the conversion of a digital block and use of same 380/37 ; 380/28; 380/42
5222136 Encrypted communication system 380/266; 380/29; 380/43; 380/284
5231668 Digital signature algorithm 380/28 ; 380/30
5237611 Encryption/decryption apparatus with non-accessible table of keys 380/284; 380/30; 380/44; 380/45; 380/243; 713/181; 713/194
5276737 Fair cryptosystems and methods of use 380/30 ; 380/286
5278907Analog scrambling with continuous synchronization - Audio Samples -
5299262 Method for exponentiating in cryptographic systems 380/28 ; 380/30; 713/168; 713/174; 713/180
5301247 Method for ensuring secure communications 380/43; 380/46; 380/47; 380/277; 380/284
5305384 Apparatus, system and method for transmitting secure signals over narrow spaced channels -300 Hz to 3200 Hz spaced 11.4 kHz
5311176  Method and apparatus for generating Walsh codes -
5363376 Method and apparatus for synchronizing timing among radio ports in wireless communications systems
5428686 - Secure communication system having long-term keying variable -  NSA patent about mixing a key held in the scrambler with a key sent over the air.
5455861
Secure telecommunications - using encryption only over part of the comm path
5528693 Method and apparatus for voice encryption in a communications system
5787180 Method of connecting a scrambler or encryption device to a hand-held portable cellular telephone - mike and speaker connections
5822430 System for encoding encryption/decryption information into IFF challenges Oct 13, 1998 380/260; 342/45; 380/274; 380/277
5852803 Apparatus, System and Method for Recording and/or Retrieving Audio Information Dec 22, 1998 704/270; 704/272 (talking label)

2000

6097812 Cryptographic system Friedman Aug 1, 2000 380/26 ; 341/50; 341/90; 341/91; 380/287; 380/52; 380/56; 380/57; 380/59
6130946 Cryptographs Friedman Oct 10, 2000 380/26 ; 341/50; 341/90; 341/91; 380/287; 380/52; 380/56; 380/57; 380/59
patent 6175625
6175625 Control circuits for electric coding machines, Laurance F. Safford, Donald W. Seiler, NSA, App: 1944-12-15, TOP SECRET 57 Years; Pub: 2001-01-16, 380/26; 341/50; 341/90; 341/91; 380/287; 380/52; 380/56; 380/57; 380/59 - SIGABA (jproc: ECM2)
Calls:
1540107 Apparatus for the Production of Cipher Documents especially for Telegraphic Dispatch AG Damm 380/52 ; 400/474; 400/77
2116683 Coding and Decoding Machine WS Lemmon  380/55 ; 400/373; 400/474; 400/477 -
2116731 Coding and Decoding Machine AR Noll  380/55 ; 400/474; 400/478; 400/479; 400/77

7088826 Method for providing a crypto key and check word to an encryption device, Christian L Houlberg, Gary S. Borgen (Navy), Aug 8,
2006, 380/277; 380/278; 380/279; 380/280; 713/193 - for use in missile, mentions KOI-18 & KYK-13
calls:
H1414 Nonvolatile memory system for storing a key word and sensing the presence of an External Loader Device and Encryption Circuit, Gary S. Borgen (Navy),
Feb 12 1991, 380/4; 380/9; 380/21; 380/49; 380/50; 395/425 - for use in missile
mentions:
4392241 Digital Interface System, Dennis P. Hurst (Navy), Jul 5, 1983, 455/26; 455/27 - Red - Black com system
calls:
3262116 SATELLITE AND SPACE COMMUNICATIONS SYSTEMS Jul 1966
3879582 Data Loop Communication System, Apr 1975
3964056 System for transferring data between central units and controlled units Jun 15, 1976
3970994 Communication switching system Jul 20, 1976
3993997 Communication system and method Nov 23, 1976
4034346 Interface for establishing communications between a data-processing unit and a plurality of stations, Jul 5, 1977
4047162 Interface circuit for communicating between two data highways Sep 6, 1977
4140972 System for synchronizing synthesizers of communication systems, Feb 20, 1979
4184117 Communication security method and system, Jan 15, 1980
4320514 Spread spectrum FH-MFSK radio receiver, Mar 16, 1982
4563546 Method for preventing "compromising radiation", Ekkehard Glitz (Licentia Patent-Verwaltungs-GmbH),
Jan 7, 1986, 178/220.1; 178/220.9; 178/221.9; 179/15M - generates data that is the inverse of the actual data so that they balance each other.
calls:
3077518 Apparatus for Camouflaging Communication Signals, Gustav GUANELLA (Patelhold  Switzerland) Feb 12 1963 - pulse manipulation keying
3133991 Method and Apparatus for Masking Communication Signals, GUANELLA May 1964 - voice signal is sampled and mixed with another signal resulting in a noise like encrypted signal.
3634665 SYSTEM USE OF SELF-TESTING CHECKING CIRCUITS Jan 1972
4176247 Signal scrambler-unscrambler for binary coded transmission system Nov 27, 1979
4177355 Array device for data scrambling Dec 4, 1979
4225962 Mosaic printer Sep 30, 1980
4283602 Cryptographically secure communication system Aug 11, 1981
4404426 Cryptographic telegraphy programming system Sep 13, 1983
4447672 Device for encrypting each input data bit by at least one keying bit decided by a code pattern and a bit pattern of a predetermined number of preceding encrypted bits, May 8, 1984
Model KGV-68 encryption circuit manufactured by Motorola
enciphering device described in U.S. Pat. No. 4563546
calls:
4097923 Remote postage meter charging system using an advanced microcomputerized postage meter Jun 27, 1978
4247908 Re-linked portable data terminal controller system Jan 27, 1981
4376299 Data center for remote postage meter recharging system having physically secure encrypting apparatus and employing encrypted seed number signals, Mar 8, 1983
4392241 Digital interface system, Jul 5, 1983
4424573 System for entering a postage meter serial number into a nonvolatile memory from an external channel after assembly of the meter Jan 3, 1984
4470127 Data terminal with error checking file transfer mode, Sep 4, 1984
4563546 Method for preventing "compromising radiation" Jan 7, 1986
4654860 Spacecraft telemetry regenerator, Mar 31, 1987
4800590 Computer key and computer lock system, Jan 24, 1989
5046006 Mutual missile control system, Sep 3, 1991
4465901 Crypto microprocessor that executes enciphered programs Aug 14, 1984 - 178/220.8; 178/220.9; 200/610.8; 364/200
A microprocessor for executing computer programs which are stored in cipher to prevent software piracy.
5458041 Air defense destruction missile weapon system Oct 17, 1995
5481610 Digital radio transceiver with encrypted key storage Jan 2, 1996 Ericsson Inc.
5513261 Key management scheme for use with electronic cards Apr 30, 1996
5654698 Missile telemetry data interface circuit Aug 5, 1997 - PCM data stream -> TTL mixed with sync
PIC 16F84
H1414 Nonvolatile memory system for storing a key word and sensing the presence of an External Loader Device and Encryption Circuit, Gary S. Borgen (Navy),
Feb 12 1991, 380/4; 380/9; 380/21; 380/49; 380/50; 395/425 - for use in missile
6859537 Non-volatile memory for use with an encryption device Feb 22, 2005 - mentions KOI-18
same as 6968061
6968061 Method which uses a non-volatile memory to store a crypto key and a check word for an encryption device Nov 22, 2005
A method using a Non-Volatile Memory circuit which operates as an interface between a key loader and an encryption device in a missile's telemetry system. The method includes a step for storing a crypto key and an associated check word and a backup crypto key and check word in the EEPROM of a microcontroller, and a step for indicating the status of a load of the crypto key in the microcontroller as well as a step for indicating the status of an erase of the crypto key from the microcontroller. The method also includes a step for turning off the missile's transmitter when a key load occurs to prevents transmission of the crypto key and its corresponding check word. The method further includes a step for erasing the crypto key and its associated check word from an EEPROM within the microcontroller upon a missile launch.
mentiones KOI-18
Might be a description of the PPS-SM used in early GPS receivers like the Trimpack and PLGR
7088826 Method for providing a crypto key and checkword to an encryption device
same as 6968061
called by:
7321910 Microprocessor apparatus and method for performing block cipher cryptographic functions Jan 22, 2008
7212638 Wireless cryptographic fill system and method, Michael Thomas Kurdziel, John Michael Trinidad (Harris), May 1, 2007, 380/273; 380/270
Prior Art includes the AN/CYZ-10 (Crypto Machines web page).
calls:
4281216 Key management for encryption/decryption systems Jul 28, 1981 Motorola FIPSP46 60+ patent pages of software flow diagrams.
5960085 Security badge for automated access control and secure data gathering Sep 28, 1999 (not the same but similar RFID lock)

Enigma Related German (DE) Patents

Ralph Simpson purchased a package of German patents related to enigma.  I used that as a starting point to search for more Crypto patents.  The numbering matches Ralph's.

1. DE5650A - no pdf, no figures, but there is English text
2. DE14877 Ernst George, Espacenet - "
3. DE61472 Espacenet - "
4. DE68167 - "
5. DE89897 - "
6. DE107347 - "
        US641481 Cipher apparatus, Giovanni Battista Nob Valvasori, 1900-01-16
7. DE184674 - "
        AT33211 Cryptographic apparatus, 1908-06-10
        FR380052A/en Device for encrypted correspondence, 1907-11-28
        GB190716588A Apparatus for Correspondence in Clipher, Carl Haas, Heinrich Studt, 1907-12-19,
        US875070 Apparatus for correspondence in cipher, Carl Haas, Heinrich Studt, 1907-12-31, 380/58 - with pdf version -  M94  https://prc68.com/I/M94.shtml#Patents
        CA109529A/en Apparatus for writing in cipher, Carl Haas, Heinrich Studt, 1907-12-31 - no pdf, no figures, no text
        CH40479A/en Apparatus for correspondence in cipher, Carl Haas, Heinrich Studt, 1908-07-16 - no pdf, no figures, no text
8. DE214964C/en - no pdf, no figures, but there is English text
9. DE365840C/en
        hGB187312 Improvements in or relating to cyphering machines, 1922-10-16 - no pdf, no figures, but there is English text
        CH96888A/en Encryption device, Henkels Albert, 1922-11-16 - no pdf, no figures, but there is English text
        US1515680 Coding and decoding machine, Henkels Albert, 1924-11-18, 380/57 - with pdf version  https://prc68.com/I/Cryptopat.shtml#1515680
10. DE383003C/en - no pdf, no figures, but there is English text
        GB154962 Improvement in code machines, 1920-12-06, - no pdf, no figures, but there is English text - Powers holds many patents related to census taking
        CA203729A/en Code machine, 1920-09-07 - no pdf, no figures, but there is English text
        ES79281A1/en A procedure, with its corresponding apparatus, for automatic cryptography, 1921-12-01 - no pdf, no figures,no text
11. DE393297C/en - no pdf, no figures, but there is English text
        FR492681A/en - no pdf, no figures,no text
        GB125032 - no pdf, no figures, but there is English text
        hIT1154761B/en
        DK31138C/en - no pdf, no figures,no text
        CH97076A/en - no pdf, no figures, but there is English text
12. DE400795C/en - no pdf, no figures, but there is English text
        DE416219C/en Encryption machine, Securitas, 1925-07-08,
        hUS1533252 Coding and decoding machine, Koch Hugo Alexander, Securitas, 1925-04-14, 380/51; 400/176 -
13. DE407804C/en -
no pdf, no figures, but there is English text
        DE429122C/en Cipher machine with a plurality of cipher rollers which cause the characters to be interchanged -no pdf, no figures, but there is English text
        US1777425 Electric cipher-writing machine, Bernstein Paul, Chiffriermaschinen, 1930-10-07, - improved rotor machine
14. DE409301C/en -
no pdf, no figures, but there is English text - see 12. for more Securitas patents
15. DE412582C/en - no pdf, no figures, but there is English text, for more Chiffriermaschinen see 13.
16. DE414547C/en -
        FR684136A/en - Telegraph apparatus for secret telegraphy, Richard Michel, Richard Dreyse, 1930-06-21 - no pdf, no text
17. DE416833C/en -
no pdf, no figures, but there is English text
18. hDE425147C/en -
no pdf, no figures, but there is English text
19. DE429242C/en -
no pdf, no figures, but there is English text
20. DE452194C/en - Electric device for encryption and decryption, Willi Korn, Chiffriermaschinen, 1928-11-14
        9 more crypto patents, one US
        1938028 Electrical coding and de-coding device, Korn Willi, Chiffriermaschinen, 1933-12-05,
380/26 - has the feel of the M-209?
12. DE400795C/en
- no pdf, no figures, but there is English text
13. DE407804C/en, Electric key cipher, Paul Bernstein, Chiffriermaschinen, 1925-08-22, -
no pdf, no figures, but there is English text
        1777425 Electric cipher-writing machine (see above)
14. DE409301C/en -
no pdf, no figures, but there is English text
15. DE412582C/en -
no pdf, no figures, but there is English text
16. DE414547C/en -
no pdf, no figures, but there is English text
17. hDE416833C/en
- no pdf, no figures, but there is English text
18. DE425147C/en -
no pdf, no figures, but there is English text
19. DE429242C/en -
no pdf, no figures, but there is English text
20. hDE452194C/en - Electric device for encryption and decryption, Willie Korn, Chiffriermaschinen, 1928-11-14, See:
1938028
21. DE454392C/en - no pdf, no figures, but there is English text
22. DE519925C/en Encryption device, 1931-03-05 - no pdf, no figures, but there is English text
23. DE534947C/en Electric encryption and decryption device, Willie Korn, Chiffriermaschinen, 1931-10-06 - - no pdf, no figures, but there is English text
24. DE577075C/en Encryption device, Erich Kuhles, 1933-05-23, - no pdf, no figures, but there is English text
25. DE586199C/en Device for encryption and decryption, 1933-10-17,
- no pdf, no figures, but there is English text
26. DE607638C/en Encryption device, Willie Korn, Chiffriermaschinen, 1935-01-04,
no pdf, no figures, but there is English text
27. DE618826C/en Device for encrypting and decrypting messages, August Cremer, 1935-09-16,
no figures, but there is English text
28. DE629972C/en Encryption machine, Dr Ernst Braeier, 1936-05-16,
29. DE667562C/en Encryption machine with adjusting device to be operated by adjusting members, 1938-11-14, -

Spy Satellite

5345238 Satellite signature suppression shield, Morton T. Eldridge, Karl H. McKechnie, Richard M. Hefley, Teledyne Inc, 1994-09-06 - looks like ice cream cone pointing to the Earth.
Anatomy of a Spy Satellite, USA-53 (NASA: KH 11-10) and USA-144 (NASA: KH 12-4) "Misty" (Wiki) YouTube: Amateur Optical and Radio Based Satellite Tracking, Aug 4, 2018 (poor sound)

APX-6 IFF Transponder

Louis Alan Hazeltine (Wiki) - Hazeltine Corporation (Wiki) - Neutrodyne (Wiki) -  Radio & Television, AGC,
Photo:

File:Hazeltine AN-APX-6 Identify Friend or Foe (IFF) transponder, introduced 1950 - National Electronics Museum - DSC00301.JPG -

General Patents
2480872 Beam tube receiver input, James R Moore,
Sec of War, App: 1942-11-28, TOP SECRET, Pub: 1949-09-06, - T/R switching
2498561 Adjustable band-pass selector,
Harry J Lipkin, Sec of War, App: 1945-09-06, TOP SECRET, Pub: 1950-02-21, - wide IF BW for accurate pulse timing, narrow IF BW for sensitivity
2597352 Decoding device, Jr Edward F Macnichol, Sec of War, App: 1944-10-10, TOP SECRET, Pub: 1952-05-20, - depends on the time between a start pulse and a data pulse. 12.5 uS mentioned a number of times.
2606282 Pulse transponder,
Harry J Lipkin, Sec of War, App: 1945-07-09, TOP SECRET, Pub: 1952-08-05, -  "...generally known as beacons. When used for navigation and as . transponders when used for identification pur poses."
2567851 Pulse-blocking circuit, Harry J Lipkin, Sec of War, App: 1945-08-01, TOP SECRET, Pub: 1951-09-11, - tube multivibrtor (flip-flop),
2679043 Beacon receiver, Harry J Lipkin, Grambsch Russel, Sec of War, App: 1946-05-21, TOP SECRET, Pub: 1954-05-18, - concerned with AGC & responding only to the main RADAR lobe.
2679580 Wide band receiver-transmitter, Ware Harold, Sec of War, App: 1945-01-24, Pub: 1954-05-25, - acorn tube, Interrogator Responder Transmitter/ Interrogator Responder Receiver.

Hazeltine
2188970 Electric timing system, John C Wilson, Hazeltine Corp, 1940-02-06, - using lumped delay lines for working with TV pulses. involves pulse to pulse timing.
2327248 Wave-signal translating channel, Nelson P Case, Hazeltine Corp, App: 1942-05-08, W.W.II, Pub: 1943-08-17, - IFF?
2398694 Carrier-wave generating system, Nelson P Case, Hazeltine Corp, - generating correct frequency for given channel, IFF?
2403889 Telemetering system, Toro Michael J Di, Hazeltine Research, App:, TOP SECRET, Pub: 1943-08-24, - maybe to encode the altimeter onto an IFF type system?
2413440 Electronic switch, John F Farrington, Hazeltine Research, App: 1942-05-15, W.W.II, Pub: 1946-12-31, - IFF?
2413451 Ultra high frequency tuning unit, Johnson John Kelly, Hazeltine Research, App:1942-10-03, W.W.II, Pub: 1946-12-31, - TV or IFF?
2413607 Time-delay network, Toro Michael J Di, Hazeltine Research, 1946-12-31, - TV or IFF?
2415359 Wave-signal translating system, Bernard D Loughlin, Hazeltine Research, Priority: 1943-12-31, TOP SECRET, Pub: 1947-02-04, - "This invention relates, in general, to wave-signal translating systems and is particularly directed to coding or secrecy aspects of transponder systems. As used throughout this specification and in the appended claims, the term “transponder system' is intended to describe a wave signal translating system which includes a receiving system and a transmitting system so arranged that a predetermined answer or reply signal is transmitted in response to a received interrogating signal, the reply and interrogating signals preferably comprising radiant-energy wave signals."
2421136 Gain control system for pulse modulation receivers, Harold A Wheeler, Hazeltine Research, App: 1945-06-01, W.W.II, Pub: 1947-05-27, - "...for use in a radio-locating and direction-finding system of the type utilizing pulse-modulated signals ..." "For example, the coded signal may include a pair of pulse components, individually having a rectangular wave form and fixed duration but a time separation that is variable in a code sequence. "
2426454 Electronic switch, Johnson John Kelly, Hazeltine Research, App: 1942-05-27, W.W.II, Pub: 1947-08-26, - IFF? pulse train with variable widths
2426454 Electronic switch, Johnson John Kelly, Hazeltine Research, App: 1942-05-27, W.W.II, Pub: 1947-08-26, - IFF? pulse train with variable widths
2454865 Time-delay network, Toro Michael J Di, Hazeltine Research, App: 1945-06-18, W.W.II, Pub: 1948-11-30, -
2457212 Time-delay network, Toro Michael J Di, Hazeltine Research, App: 1945-06-18, W.W.II, Pub: 1948-12-28, -
2483097 Position indicator for airborne traffic, Mcilwain Knox, Hazeltine Research, App: 1946-09-12, W.W.II, Pub: 1949-09-27, - bearing and altitude of aircraft
2522706 Multiple-reflecting time-delay system, Toro Michael J Di, Hazeltine Research, 1950-09-19, - television
2570805 Signal-translating system, Hazeltine Alan, Hazeltine Research, App: 1946-07-20, W.W.II, Pub: 1951-10-09. -
2589808 Transpondor system, Charles J Hirsch, Hazeltine Research, App: 1946-10-21, W.W.II, Pub: 1952-03-18, - 2 ground stations give position and direction of aircraft. -

Hirsch worked for T.A. Edison up until 1930, patent 1996378 Hum elimination (in AM radio) in his name 1931, then started at Hazeltine Research by 1944.
2462265 Frequency divider, App: 1944-08-16, W.W.II, Pub: 1949-02-22, - related to A-scope RADAR display
2572725 Path-indicating system for Mobile Craft, App: 1946-02-15, W.W.II, Pub: 1951-10-23, - for blind landing
2652194 Electrical Computer, 1953-09-15, - tubes, makes use of the frequency divider, not clear what it's for
2686910 Wave-signal transmitting system, 1954-08-17, - VOR (Wiki)
2640925 Electron discharge signal-sampling device, 1953-06-02, - DME (Wiki)
2754481 Electrostrictive time-delay signal translating device, 1956-07-10, - prior art barium titanate
2827564 Time-delay signal-repeater system, 1958-03-18, - MTI (Wiki)
2996707 Radar control system, 1961-08-15, - DME (Wiki)
2795656 Repeater system, 1957-06-11, - for bipolar signals down to DC, but what application?
3002090 Automatic-gain-control system, 1961-09-26, -
3015689 Color-television camera, 1962-01-02, -
3235806 Signal translating circuit, 1966-02-15, - based on Tunnel Diodes work done at and for RCA, not Hazeltine.
3387299 Lightweight iff detection system, John H Gutman, Huebscher Herbert, Hazeltine Research, 1968-06-04, - for use on the ground with SAM (Wiki).

Patents after the APX-6

2515178 Means for synchronizing detection and interrogation systems, Barchok Donald, Army, App: 1943-10-12, W.W.II, Pub: 1950-07-18, -
2796602 Aircraft identification and location system, Gerard C Hess, Norman H Taylor, Raymond M Wilmotte, PADEVCO Inc, App: 1947-08-08, Pub: 1957-06-18, - 32 patent citations.
3004253 IFF System, Teck A Wilson, Hughes Aircraft, 1961-10-10, -
3750163 IFF System, K Hecker, Navy, 1973-07-31, -
5892478 Adaptive azimuth processing for monopulse IFF interrogators, Leonard A. Moss, Hazeltine Corp,


QST Sep 1960: Communication on 1215 Mc. with the APX-6, printed page 30. - converting for use in ham band for AM voice.
QST Feb 1961: Practical Operating HInts for 1215 Mc. printed page 27. -

Related: APR-1 & APR-4 surveillance receivers.  The Agilent E4404B ESA-E 9kHz - 6.7 GHz Spectrum Analyzer is far far more capable, but is also decades newer.

Links

Brooke's Home, Patents, Crypto, Crypto Machines, Military Information, Electronics, Page

page created 16 June 2003.