| 5276738 |
Software data protection mechanism |
| Jan-4-1994 |
A protection mechanism includes means for taking an input binary value and generating a unique key value as well as performing the reverse operation of taking a key value and generating an input binary... |
| 5272753 |
Scrambling apparatus |
| Dec-21-1993 |
A scrambling apparatus includes an IC card connector for receiving an IC card in which at least either scramble control information or unscramble control information is written in advance, a reading circuit... |
| 5257282 |
High speed code sequence generator |
| Oct-26-1993 |
A novel low speed code sequence generator having a set of parallel flip-flops is provided and comprises a vector generator in series between the outputs and the inputs of the set of parallel flip-flops... |
| 5245661 |
Distributed sample scrambling system |
| Sep-14-1993 |
A distributed sample scrambling system comprising scrambler and a descrambler. The scrambler includes a first shift register generator (SRG) 2 for generating scrambler SRG sequence, an exclusive OR gate... |
| 5245660 |
System for producing synchronized signals |
| Sep-14-1993 |
A system for producing two synchronized signals comprises a nonlinear dynamical primary system and a nonlinear dynamical secondary response subsystem. The primary system comprises a nonlinear dynamical... |
| 5235645 |
Scrambler/descrambler system for data transmission |
| Aug-10-1993 |
A scrambler system is provided for the detection and separation of synchronization signals from data signals, and for the scrambling of the data signals such that no long and repeatable series of one's... |
| 5231667 |
Scrambling/descrambling circuit |
| Jul-27-1993 |
A scrambling/descrambling circuit that may be manufactured as a CMOS arrangement in LSI format and free of constraints on the degree of the generating polynomial involved. Scrambled (or descrambled) "m"... |
| 5226082 |
Variable length decoder |
| Jul-6-1993 |
Apparatus for decoding a stream containing codes of a variable length code (VLC) takes advantage of the fact that a trie representation of the VLC can be pruned to leaves that each represent a complete... |
| 5224165 |
High speed word generator |
| Jun-29-1993 |
An improved high speed word generator (30) which includes a white noise generator (12) for providing first and second bits and exclusive or (XOR) means (32) for providing an output signal which is the... |
| 5222142 |
Sequence generator |
| Jun-22-1993 |
An improved sequence generator. The inventive generator (10) is adapted for use with a source (12) for providing successive bits of random data. The invention (10) includes a shift register (18) with a... |
| 5222100 |
Range based acquisition system |
| Jun-22-1993 |
A novel range based acquisition system includes a receiver for receiving PN encoded signals coupled to a novel range based variable dwell correlator which detects and acquires uniquely timed received transmitter... |
| 5204901 |
Public key cryptographic mechanism |
| Apr-20-1993 |
A public key cryptographic mechanism provides a measurable degree of minimum security, in an ensemble sense, for two Parties, A and B, to establish a commonly held private cryptographic keying variable... |
| 5202694 |
P-code generation |
| Apr-13-1993 |
Improved apparatus for generation of the P-code sequences used in global positioning by issuance and sensing of code sequences issued by a plurality of satellites. The improved apparatus generates the... |
| 5193115 |
Pseudo-random choice cipher and method |
| Mar-9-1993 |
A cipher system is disclosed in which each character of a plaintext alphabet has associated with it a randomly distributed collection of integers of a given length. This collection of integers is secretly... |
| 5132986 |
CSK communication system |
| Jul-21-1992 |
The present invention provides new arrangements for various components of a CSK communication system: modulator, correlators, demodulator, carrier detection circuit, and synchronization control circuit.... |
| 5123045 |
Comprehensive software protection system |
| Jun-16-1992 |
An efficient software protection scheme is presented in which a data processing system provides comprehensive software protection using hardware and software measures. Specifically, it provides protection... |
| 5077792 |
Franking system |
| Dec-31-1991 |
Credit in a credit register of a franking meter is reset by telephone communication with a resetting terminal. A request for a selected credit amount is transmitted from the meter apparatus to the terminal... |
| 5048052 |
Spread spectrum communication device |
| Sep-10-1991 |
The present invention is a spread spectrum communications system where the plural pseudonoise codes are switched such that one pseudonoise code represents binary "1" and another pseudonoise code represents... |
| 5031191 |
Spread spectrum signal demodulation circuit |
| Jul-9-1991 |
A spread spectrum signal demodulation circuit includes a multiplier which multiplies an input spread spectrum signal by a demodulation PN code, and a demodulation PN code generator generates the demodulation... |
| 5029210 |
Cooperative communication system |
| Jul-2-1991 |
A cooperating communications system in which at least two stations and a connecting communications link form a cooperative communicating loop. Each station contains a plurality of amplification stages,... |
| 5022049 |
Multiple access code acquisition system |
| Jun-4-1991 |
Apparatus for generating a complex composite code for fast acquisition by multiple access users is provided which comprises a composite code generator having an in-phase channel code generator and a quadrature... |
| 5007016 |
Fractal-type periodic temporal signal generator |
| Apr-9-1991 |
A signal generator generates a temporal signal with a periodic configuration defined by an arrangement of seed patterns resulting from a branching construction iteratively using laws for composing several... |
| 5001755 |
Security system network |
| Mar-19-1991 |
The present invention uniquely applies data communications network techniques to a security system. A series of slave transponders are coupled via a full duplex bus to a master node. The master node is... |
| 5001754 |
Encryption system and method |
| Mar-19-1991 |
A method for encrypting data is described which employs a key that includes a plurality of alphanumeric characters and a memory array adapted to operate on NxM pixel display. The method includes the steps... |
| 5001723 |
Sinusoidal M-ary orthogonal keyed decoding |
| Mar-19-1991 |
A spread spectrum communications system is described for recovering data from a signal having a first carrier frequency modulated by one of at least four phase modulations, each phase modulation orthogonal... |
| 4991209 |
Random local message encryption |
| Feb-5-1991 |
Data transmission to an aircraft is secured by encrypting the data between a remote data source and the aircraft. The encryption is initiated when a random number is coupled to the remote location where... |
| 4979832 |
Dynamic substitution combiner and extractor |
| Dec-25-1990 |
A first data source and a second data source are combined into a complex intermediate form or result; the first data source can be extracted from the intermediate form using the second data source. The... |
| 4972480 |
Holographic communications device and method |
| Nov-20-1990 |
A holographic device and method encrypts a time dependent data signal, s(t), by a complex time dependent phase shifting signal. This produces a new signal whose modulus is equal the absolute value of the... |
| 4972475 |
Authenticating pseudo-random code and apparatus |
| Nov-20-1990 |
A matrix code generating method generates a first predetermined code in binary form. A second step permutes the first determined code according to a non-linear feedback method described as pseudo-random.... |
| 4972474 |
Integer encryptor |
| Nov-20-1990 |
A integer encryptor and decryptor, with the integer encryptor comprising a pseudorandom source, a discrete-time source, guard-band means, and adding means. The pseudorandom source generates a random-data... |
| 4968981 |
GPS receiver apparatus |
| Nov-6-1990 |
A GPS receiver apparatus retrieves a maximum correlation point between a PN code involved in a satellite signal and a generated PN code with use of n detecting means each concurrently processing the retrieval... |
| 4965827 |
Authenticator |
| Oct-23-1990 |
An authenticator for digital data is derived by generating a numerical array, using a secret key to controllably shift the relative positions of the elements of the array, and applying the scrambled array... |
| 4944009 |
Pseudo-random sequence generator |
| Jul-24-1990 |
A seed random sequence is extended in successive nodes of a tree structure of a random sequence generator. At each node, an input sequence is expanded to an output sequence substantially greater than the... |
| 4944007 |
Public key diversification method |
| Jul-24-1990 |
A method is disclosed whereby individual members of a group of members or entities may be provided, under the control of a trusted member, referred to as the parent, with respective individual secret keys... |
| 4905278 |
Scrambling of analogue electrical signals |
| Feb-27-1990 |
In a system in which an audio signal is scrambled by being divided into blocks each comprising a plurality of segments, and the segments are re-ordered within the blocks to provide the scrambled signal,... |
| 4905176 |
Random number generator circuit |
| Feb-27-1990 |
A very large scale integrated (VLSI) compatible, random number generator which is highly invulnerable to cryptographic attack. The invulnerability to cryptographic attack is based upon a low frequency... |
| 4893339 |
Secure communication system |
| Jan-9-1990 |
Disclosed is a synchronous secure communication system wherein an information signal is encrypted in an encryption means. The encrypted signal is compressed to allow the insertion of a synchronization... |
| 4876716 |
Key distribution method |
| Oct-24-1989 |
A key distribution method and system for distributing a key over an insecure communication channel between first and second systems. Both first and second systems generate respective random numbers, calculate... |
| 4870682 |
Television scrambling system |
| Sep-26-1989 |
A signal scrambling system is provided in which the scrambler includes a transition limiter which limits the size of changes in the amplitude of the input clear signal, a device for generating a pseudo... |
| 4850019 |
Data randomization equipment |
| Jul-18-1989 |
Input data is split by a splitting part into a plurality of block data having an equal data length to be processed through respective channels. Each channel data is subjected in a function operation part... |
| 4845749 |
Secure teleconferencing system |
| Jul-4-1989 |
A secure audio teleconferencing system is disclosed. The secure teleconferencing system comprises a centralized facility or bridge to which a plurality of participants is connected. The role of the bridge... |
| 4829589 |
Anti-tapping system |
| May-9-1989 |
The system relates to a system for preventing unauthorized viewing of CATV etc. wherein each terminal is provided with a terminal own address generator and an auxiliary address generator. The center station... |
| 4817148 |
Signal scrambling transmission system |
| Mar-28-1989 |
There is disclosed a signal scrambling transmission system in which the data is scrambled at the transmit end by logically combining the data with a pseudo random sequence generated by a ROM prior to transmission.... |
| 4809295 |
Code lengthening system |
| Feb-28-1989 |
Apparatus and a method of generating very very long pseudonoise (PN) spread spectrum codes is provided where the code is so long that it need never repeat itself during actual use. The transmitter is adapted... |
| 4807290 |
Self-synchronizing scrambler |
| Feb-21-1989 |
A self-synchronizing scrambler for high bit rates comprises a plurality of scrambler stages operating in parallel and which respectively represent the series connection of a first modulo-2 adder and a... |
| 4799259 |
Monolithic random digital noise generator |
| Jan-17-1989 |
A random digital signal generator circuit responsive to a clock signal from a block signal source for outputting a sequential series of logic signals. The circuit comprises a clocked flip-flop that provides... |
| 4797672 |
Voice network security system |
| Jan-10-1989 |
A voice network security system is disclosed which provides improved security aspects in transmitting voice messages between remote locations for use in a business environment. The security aspects of... |
| 4791669 |
Encryption/decryption system |
| Dec-13-1988 |
An encryption/decryption system for a communication channel increases the number of values for the encryption key variable without increasing the length of a cipher feedback register. This is done by providing... |
| 4771463 |
Digital scrambling without error multiplication |
| Sep-13-1988 |
The present invention describes a circuit which allows a data stream to be scrambled by continuously running uninterrupted Pseudo Random sequence without multiplying errors. This is accomplished by allowing... |
| 4755969 |
Pseudo random sequence generation |
| Jul-5-1988 |
Circuits for generating sequences of pseudo random binary digits wherein the circuit can be easily programmed to change the sequence. The sequences are obtained by modulo-2 addition of digits retrieved... |
