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
-
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
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
1356546
Cyphering System Oct 26, 1920380/47
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 1491358G
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
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
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
1556964Electric
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
1584660Ciphering 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
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 1724163400/365; 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 1777425Electric 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
1938028Electrical
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
2206590
Portable Transmissin System, Webb Jr., Jul 2, 1940 - simple speech
inverter 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
2401402
Secret Communication System 380/28 - June 4, 1946 (RCA) - voice by
using a record (or photographic image) as a key 2402182
Rotor, L. Rosen Jan 18, 1946 L. Rosen 380/26; 380/33;
380/58 - contact pressure is relieved during rotation to minimize
wear 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 2406031Telegraph
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 2802047Electric 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 4275265Complete 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
2851794Cryptographic Coding
and Decoding Apparatus, B. C. W. Hagelin Sep 15, 1968 380/57 -
Crypto AG CD-55 first of the pocket
machines
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
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 -
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
3965296Signaling
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
3965296Signaling
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 - 4154006Coding and decoding
machine Wood; Chester C, May 15, 1979 380/57 ;
341/2 -
Searcing for more patents related to
4154006 4143978
Electro-mechanical cipher machine, Bern
Anderson, Donald
W. Seiler, Navy,
1979-03-13, - 6175625Control
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
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, 1982380/30;
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)
6175625Control
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
7088826Method 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. DE61472Espacenet
- "
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, -
