Patents
Sitemap › H04 - Electric communication technique › H04K - Secret communication; Jamming of communication › H04K 1 - Secret communication
Patents for H04K 1 - Secret communication (16,771)
01/1980
01/15/1980US4184117 Communication security method and system
01/08/1980US4182933 Secure communication system with remote key setting
12/1979
12/18/1979US4179658 Secret-signalling system utilizing noise communication
12/18/1979US4179657 Anti-jamming communication system
12/18/1979US4179586 System of encoded speech transmission and reception
11/1979
11/27/1979US4176316 Secure single sideband communication system using modulated noise subcarrier
10/1979
10/30/1979US4172968 Electrical system
10/30/1979US4172963 Checker and automatic synchronizer for coding equipment
10/16/1979US4171513 Secure communications system
10/09/1979US4170757 Method of and apparatus for transmitting clandestine radio signals
10/03/1979EP0004340A2 Pseudorandom generation of orthogonal matrixes for scrambling purposes
10/02/1979US4169993 Intercept receiver for double-side-band, noise-like signals
09/1979
09/11/1979US4167700 Digital voice protection system and method
08/1979
08/07/1979US4163872 Secret pulse signaling system
07/1979
07/03/1979US4160123 Methods of and apparatus for the encoded transmission of information
06/1979
06/27/1979EP0002580A1 A process for the verification of cryptographic operational keys used in data communication networks
06/26/1979US4159399 Security communication system using polarity inversion
05/1979
05/22/1979US4156205 Binary frequency synthesizer
05/01/1979US4152650 Continuously-synchronized tracking receiver for a priori defined swept carriers
05/01/1979US4152545 Pulse position modulation secret communication system
04/1979
04/10/1979US4149035 Method and apparatus for enciphering and deciphering audio information
03/1979
03/20/1979US4145717 Subscription TV audio carrier recovery system
03/20/1979US4145716 Descrambling device in CATV system
01/1979
01/16/1979CA1046669A1 Spread spectrum communication techniques for a code division message multiplexing system
01/09/1979US4133977 Voice scrambler using syllabic masking
11/1978
11/21/1978US4126761 Method of and means for processing an audio frequency signal to conceal intelligility
11/14/1978US4125744 Communication system
09/1978
09/05/1978US4112368 Constant amplitude carrier communications system
07/1978
07/25/1978US4102521 System for signal coding
07/11/1978US4100374 Uniform permutation privacy system
07/04/1978US4099027 Speech scrambler
04/1978
04/25/1978US4086435 Method of and means for scrambling and descrambling speech at audio frequencies
02/1978
02/28/1978US4077005 Secure position identity and time reporting system
01/1978
01/24/1978US4070693 Secure television transmission system
01/10/1978US4068094 Method and apparatus for the scrambled transmission of spoken information via a telephony channel
01/03/1978US4066964 Communication system
12/1977
12/20/1977US4064536 Video scrambler and descrambler apparatus
12/20/1977US4064505 Signal transmission circuit comprising a coder and a decoder
11/1977
11/22/1977US4059726 Process and apparatus for speech privacy improvement through incoherent masking noise sound generation in open-plan office spaces and the like
11/15/1977US4058677 Sound scrambling equipment
10/1977
10/18/1977US4054751 Masking noise generator
10/04/1977US4052565 Walsh function signal scrambler
05/1977
05/10/1977US4023103 Synchronizer for frequency hopping receiver
04/1977
04/26/1977US4020285 Voice security method and system
03/1977
03/22/1977US4013837 Voice security method and system
03/08/1977US4011408 Audio transmission protection apparatus
01/1977
01/25/1977US4005428 Secure remote control communication systems
01/11/1977US4002825 System for encoding and decoding amplitude modulated signals
12/1976
12/21/1976US3999005 Secure transmission of AM or FM signals
11/1976
11/30/1976US3995115 Speech privacy system
11/09/1976US3991273 Speech component coded multiplex carrier wave transmission
11/09/1976US3991271 Voice security method and system
11/09/1976US3991268 PCM communication system with pulse deletion
10/1976
10/12/1976US3985958 Secret telephony
09/1976
09/28/1976US3983327 Electrical signaling
09/07/1976US3979558 Signaling system
08/1976
08/31/1976US3978288 Method and apparatus for the secret transmission of speech signals
08/24/1976US3976839 Telephone privacy system
07/1976
07/20/1976US3970791 Voice controlled disappearing audio delay line
07/20/1976US3970790 Method and device for the coded transmission of messages
06/1976
06/29/1976US3967067 Secret telephony
06/22/1976US3965296 Signaling system
05/1976
05/25/1976US3959592 Method and apparatus for transmitting and receiving electrical speech signals transmitted in ciphered or coded form
05/18/1976US3958214 Encoded echo-ranging signal generator
04/1976
04/27/1976US3953678 Speech component key signaling system with code combinations
04/27/1976US3953677 Key signaling system with multiple pulse generators
03/1976
03/16/1976US3944745 Secret signaling system with means for preventing key disclosure
03/16/1976US3944744 Matrix coding secret signalling system
02/1976
02/10/1976US3937888 Signal transmission with secrecy
02/03/1976US3936749 Matched filter communication systems
02/03/1976US3936748 Secret communication system employing magnetic control of signal modulation on microwave or other electromagnetic carrier wave
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