| 4688251 |
Wave packet communication subsystem for determining the sync pulses and correlating the data pulses of a wave packet |
| Aug-18-1987 |
A subsystem of a wave packet communication system uses the same sets of receivers and correlators to detect both the sync pulses and the messages carried by different wave packets. The system does this... |
| 4195202 |
Voice privacy system with amplitude masking |
| Mar-25-1980 |
A voice privacy system enhances the privacy of a transmission by disguising the amplitude characteristics and cadence content of transmitted voice signals. Encoding apparatus first divides a voice signal... |
| 3970791 |
Voice controlled disappearing audio delay line |
| Jul-20-1976 |
A delay line which disappears under voice control is comprised of a pluray of shift registers delays the incoming voice signal to permit transmission of the voice scrambler preamble. The delay is removed... |
| 4575754 |
Video scrambler system |
| Mar-11-1986 |
A video signal is scrambled by partitioning the signal into blocks of segments, reversing the sequence of segments in each block, randomly delaying the reversed segments and reversing the sequence of the... |
| 4937867 |
Variable time inversion algorithm controlled system for multi-level speech security |
| Jun-26-1990 |
A method for scrambling speech such as in a mobile land based communication system is disclosed. Essentially, variable length time samples of digitized speech are stored and time inversion scrambled. The... |
| 6810087 |
Ultra-wideband communications system |
| Oct-26-2004 |
An ultra-wideband (UWB) communications system combines the techniques of a transmitted reference (TR) and a multiple access scheme called delay hopping (DH). Combining these two techniques using UWB signaling... |
| 4223182 |
Transmission of signals with privacy |
| Sep-16-1980 |
In a speech transmission system, a first privacy apparatus for making reversible alterations in speech message waves for rendering unauthorized reception of the message difficult, a second privacy apparatus... |
| 4221931 |
Time division multiplied speech scrambler |
| Sep-9-1980 |
A privacy communication system in which increased security is provided in the scrambling of speech signals. Input speech is separated into a high frequency band and a low frequency band, and each band... |
| 4168395 |
Start/stop teleprinter scrambler |
| Sep-18-1979 |
1. A start/stop cryptographic telegraphy terminal-equipment comprising electronic means for generating clock pulses, means responsive to the clock pulses for generating timing pulses occurring at a substantially... |
| 4099027 |
Speech scrambler |
| Jul-4-1978 |
A speech scrambler for rendering unintelligible a communications signal for transmission over nonsecure communications channels includes a time delay modulator and a coding signal generator in a scrambling... |
| 3937888 |
Signal transmission with secrecy |
| Feb-10-1976 |
1. In a privacy system in which the signals are divided into fragments on a time basis and the different fragments are delayed in transmission by different amounts to afford privacy, a timing means having... |
| 4064505 |
Signal transmission circuit comprising a coder and a decoder |
| Dec-20-1977 |
A coder and a decoder having delay elements of the same delay time arranged one after the other in which the signal transmission ratio code of the signal paths from the input of the circuit to the output... |
| 4392021 |
Secure facsimile transmission system using time-delay modulation |
| Jul-5-1983 |
Method and apparatus for secure transmission of analog signals, particularly facsimile signals. The analog signal is first converted to a frequency-modulated signal, if not already one, and is then converted... |
| 5805635 |
Secure communication system |
| Sep-8-1998 |
A secure communication system comprising: a first cyclical pseudo-random noise generator comprising determinable vable starting point means and an output; transmitting means for transmitting said pseudo-random... |
| 4730340 |
Programmable time invariant coherent spread symbol correlator |
| Mar-8-1988 |
An hybrid array correlator is configured of a cascaded array of individually identical correlator cells, through which a preselectable reference symbol sequence, identifiable with a symbol to be acquired,... |
| 4742546 |
Privacy communication method and privacy communication apparatus employing the same |
| May-3-1988 |
A privacy communication system in which signals transmitted from a transmitter are subjected to time base compression and expansion while the received signal is subjected to time base expansion and compression... |
| 4160123 |
Methods of and apparatus for the encoded transmission of information |
| Jul-3-1979 |
Method and apparatus for encoding transmitted data and decoding the data at a receiving facility. The data is divided into elements of equal length. Each element is assigned an age number having a value... |
| 4211891 |
Method for setting code text generators in ciphering devices |
| Jul-8-1980 |
In a procedure in which data is ciphered at a transmitter by being linked with key data generated by a code text generator and is deciphered at a receiver by appropriate linkage of the ciphered data with... |
| 4188506 |
Method and installation for masked speech transmission over a telephone channel |
| Feb-12-1980 |
A method and an installation for masked or scrambled speech transmission utilize a time-scrambling unit for dividing the speech band into at least two sub-bands, for delaying the one sub-band with respect... |
| 3970790 |
Method and device for the coded transmission of messages |
| Jul-20-1976 |
Method and apparatus are disclosed whereby messages are encoded by message element exchangers which utilize a delay device for transposing selected pairs of message elements so that the first element of... |
| 4068094 |
Method and apparatus for the scrambled transmission of spoken information via a telephony channel |
| Jan-10-1978 |
A method of scrambling and unscrambling speech transmissions by first dividing the speech frequencies into two frequency bands and reversing their order by modulating the speech information, the width... |
| 5249199 |
Method and apparatus for reducing spurious noise levels in an audio system |
| Sep-28-1993 |
An audio system (600) typically includes an audio signal processor (610), a controller (607) for controlling data signals, and a peripheral data source (613). The audio signal processor (610) exchanges... |
| 5818934 |
Method and apparatus for providing a cryptographically secure interface between the decryption engine and the system decoder of a digital television receiver |
| Oct-6-1998 |
A method for providing a secure interface between a decryption engine and a system decoder of a digital receiver, e.g., an MPEG-2 digital television receiver. The system decoder receives an encrypted bitstream... |
| 6389138 |
Method and apparatus for generating a complex scrambling code sequence |
| May-14-2002 |
A complex spreading and/or scrambling code sequence generation system uses a first complex code sequence having at least two components and a second complex code sequence having at least two components.... |
| 5058157 |
Method and apparatus for encrypting and decrypting time domain signals |
| Oct-15-1991 |
A technique for encrypting and decrypting information signals normally arranged as a succession of lines of active information, with each line having a line timing reference, such as color video information... |
| 4916736 |
Method and apparatus for encrypting and decrypting time domain signals |
| Apr-10-1990 |
Time sequential information signals, such as color video signals having a line timing reference and an active video portion, are encrypted by time shifting the active video signal portion towards and away... |
| 4247942 |
Jam resistant communication system |
| Jan-27-1981 |
1. In a communication system, a first delay line having multiple spaced taps, means for supplying successive input pulses to said delay line, whereby in response to each input pulse variously delayed pulses... |
| 6970843 |
Financial management system |
| Nov-29-2005 |
A financial transaction network includes a customer network serviced by a host processor. The financial transaction network provides customers with a plurality of diverse and interchangeable financial... |
| 4953211 |
Encryption apparatus |
| Aug-28-1990 |
Encryption apparatus mainly intended for encrypting speech signals samples a signal to be encrypted at two differing rates, and reads the sampled signal into storage means at one of said rates and reads... |
| 6970561 |
Encryption and decryption with endurance to cryptanalysis |
| Nov-29-2005 |
An encrypting apparatus includes an encrypting operation section, a determining section and a control section. The encrypting operation section carries out an encrypting operation to a plaintext using... |
| 3988538 |
Digital data scrambler and descrambler |
| Oct-26-1976 |
A digital data scrambler and descrambler for m parallel synchronized digital data streams, where m is an integer greater than one, is disclosed. The scrambler and descrambler each include m linear sequential... |
| 4324002 |
Delay-modulated random energy intelligence communication system |
| Apr-6-1982 |
1. An intelligence communication system comprising a transmitter and a receiver; said transmitter comprising non-periodic energy means for generating a carrier, means for effecting a change in the time... |
| 4125744 |
Communication system |
| Nov-14-1978 |
In a pulse code modulation system, a source of key signals comprising a source of random pulses, multisection delay device, means for applying said pulses to said multisection delay device, apparatus for... |
| 4184117 |
Communication security method and system |
| Jan-15-1980 |
6. A communication security system including a transmitting system having a lurality of sources of carrier frequencies, a source of prescheduled noise, a suppressed carrier modulator and transmitter responsive... |
| 4037159 |
Chirp communication system |
| Jul-19-1977 |
A communication system that is difficult to jam has a transmitter transmitting successive chirp signals, which start at different initial frequencies and all have the same frequency - time slope. At the... |
| 5029340 |
CATV terminal unit having an improved descrambling operation |
| Jul-2-1991 |
A CATV terminal unit descrambling operation is disclosed wherein unrecovered video pulse portions, existing because a scrambling compression period is longer than a descrambling expansion period, are eliminated.... |
| 4363130 |
Binary digital communication system |
| Dec-7-1982 |
1. A binary digital communication system comprising a transmitter and receiver: said transmitter comprising means for alternately radiating in response to the digits of a binary message two signals of... |
| 5235616 |
Bidirectional data transmission system |
| Aug-10-1993 |
A bidirectional data transmission system using the technique known as spectrum spreading by direct sequence comprises a first transmitter-receiver assembly consisting of a first transmitter section which... |
| 4011408 |
Audio transmission protection apparatus |
| Mar-8-1977 |
In delay module means, an input signal is divided into a number of subsignals, each separated from the others by a selected time delay. In a primary module the subsignals are selectively weighted and combined... |
| 4649549 |
Apparatus for synchronizing linear PN sequences |
| Mar-10-1987 |
A system and method are disclosed for synchronizning the linear PN sequences contained in a received spread spectrum signal, characterized by the provision of a resident PN generator that is responsive... |
| 4179657 |
Anti-jamming communication system |
| Dec-18-1979 |
1. A system of communications to an intended destination in a manner to elude detection by unauthorized sources, and to prevent jamming, which comprises multi-channel transmitting means, each of said channel... |
| 4302628 |
Analog signal encrypting and decrypting system |
| Nov-24-1981 |
An encrypting and decrypting system employing analog signals in which delay lines are employed in both the encrypter and decrypter so that the initial analog signal which is received may be switched by... |
