| 5369706 |
Resynchronizing transmitters to receivers for secure vehicle entry using cryptography or rolling code |
| Nov-29-1994 |
Secret Information is stored in the transmitter and receiver of the keyless entry system. The information includes a resynchronization authorization code. When resynchronization is requested by the user... |
| 5365225 |
Transmitter-receiver system with (re-)initialization |
| Nov-15-1994 |
A transmitter-receiver system (FIGS. 1 and 2), which checks the authorization to use an object (O), contains a transmitter (S), which has a transmitting element (SE) as well as one or more transmitter... |
| 5363448 |
Pseudorandom number generation and cryptographic authentication |
| Nov-8-1994 |
An automobile door lock receiver module (30) and a plurality of keychain fob transmitter units (16) contain identification numbers, secret initial values, and secret feedback masks so as to authenticate... |
| 5351300 |
Method of modifying pseudo-random sequences and device for scrambling or descrambling information components |
| Sep-27-1994 |
For dynamically modifying pseudo-random sequences of a pseudo-random sequence generator which is re-initialized at each start of the packet of information components, the information component itself is... |
| 5345508 |
Method and apparatus for variable-overhead cached encryption |
| Sep-6-1994 |
A digital encryption structure allows the varying of the computational overhead by selectively reusing, according to the desired level of security, a pseudorandom encoding sequence at the transmitter end... |
| 5341423 |
Masked data transmission system |
| Aug-23-1994 |
A method and apparatus for masking the presence and content of data transmissions includes a mobile transmitter which encodes the data by means of a pseudorandom spreading (PRS) code having a chip rate,... |
| 5321753 |
Secure communication of static information by electronic means |
| Jun-14-1994 |
A method and apparatus (10) for the secure transmission of static data (16) from a tag (11) to a remote reader (12). Each time the static data (16) is to be transmitted to the reader (12), the 10 bits... |
| 5310999 |
Secure toll collection system for moving vehicles |
| May-10-1994 |
A secure toll payment system is realized by transmitting a changeable encryption code from roadside equipment at a toll plaza to a moving vehicle. Thereafter, the moving vehicle uses it to encrypt payment... |
| 5245658 |
Domain-based encryption |
| Sep-14-1993 |
A domain-based encryption system which uses identical domains known only to the parties involved in the communication. An encrypted message is sent between communicating parties which consists of a stream... |
| 5241598 |
Rolling key resynchronization in cellular verification and validation system |
| Aug-31-1993 |
A system for the resynchronization of a rolling key used as an input among a plurality of inputs to an authentication algorithm executed in a mobile station and in a radio network providing service to... |
| 5204903 |
Secure communication equipment and secure transmission system |
| Apr-20-1993 |
In a secure transmission system in which first and second pieces of communication equipment are interconnected via a transmission line, the first communication equipment has a conversion part for encrypting... |
| 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... |
| 5191610 |
Remote operating system having secure communication of encoded messages and automatic re-synchronization |
| Mar-2-1993 |
A remote operating system for remote-controlled operation of a device provides secure communication of encoded messages between a transmitter (100) and receiver (150) of the system, and provides automatic... |
| 5177790 |
Method for generating a random number in a data processing system/and system for implementing the method |
| Jan-5-1993 |
In a data processing system using portable objects (1) such as cards incorporating memory chips (11, 12, 13, 14, 15) and a processing circuit (10), where a first memory zone (11) is electrically erasable... |
| 5148485 |
Encrypton system for digital cellular communications |
| Sep-15-1992 |
A system for generating a pseudo-random bit sequence which may be used in enciphering digital data prior to transmission or storage of the data. The bit sequence is generated by expanding a plurality of... |
| 5144667 |
Method of secure remote access |
| Sep-1-1992 |
Access to a vehicle by a remote electronic key via a radio link is secured by an exchange of encrypted signals. A remote unit having a secret number is introduced to a base unit and a common key is agreed... |
| 5101430 |
Method and device for generating and for validating a digital message and application of such a device |
| Mar-31-1992 |
In this method, a number N is assigned to transmitted and receiving stations comprising synchronous clocks (2), the coded message being obtained by calculating a time Tie from the time elapsed since the... |
| 5060266 |
Continuous cipher synchronization for cellular communication system |
| Oct-22-1991 |
A system for the synchronization of encryption devices in a digital cellular communications system. Each of the encryption devices includes a multi-bit counter and generates a pseudo-random keystream which... |
| 5008937 |
Scrambled-communication system using adaptive transversal filters for descrambling received signals |
| Apr-16-1991 |
In a scrambled-communication system, a transmitting station generates a scrambling noise having a periodically-recurrent series of noise patterns and scrambles an information signal by simply summing the... |
| 4980913 |
Security system network |
| Dec-25-1990 |
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... |
| 4914696 |
Communications system with tandem scrambling devices |
| Apr-3-1990 |
An intermediate scrambling device for a radiotelephone system is disclosed by which it is possible to establish and maintain scrambled communications between an originating scrambler terminal and the most... |
| 4856063 |
No-overhead synchronization for cryptographic systems |
| Aug-8-1989 |
Synchronization information for synchronizing encrypting and decrypting key generators (12 and 16) in a secure communications link (10) is transmitted without exacting a bandwidth penalty. Pointer comparators... |
| 4757535 |
System for encrypted information transmission |
| Jul-12-1988 |
A system for encrypted information transmission is disclosed in which so-called recording interference is suppressed. Encryption is effected by means of a periodically recurring pseudo-noise sequence (key... |
| 4754482 |
Method and apparatus for synchronizing encrypting and decrypting systems |
| Jun-28-1988 |
A synchronization method and corresponding apparatus for transmitting or storing encrypted data breaks the data into blocks and appends to each block an error detection code which is calculated from the... |
| 4742545 |
Video picture signal scrambling system |
| May-3-1988 |
A video picture signal scrambling system for subscription braodcast or cablecast television systems which can scramble video signals without adversely effecting pictures received at a subscriber's terminal.... |
| 4731840 |
Method for encryption and transmission of digital keying data |
| Mar-15-1988 |
A method for the encryption, transmission, and subsequent decryption of digital keying data. The method utilizes the Data Encryption Standard and is implemented by means of a pair of apparatus, each of... |
| 4731839 |
Method for coding and de-coding audio and video information |
| Mar-15-1988 |
There is described a method for coding and de-coding in an information-transmission system, particularly for pay-television, which comprises for coding, converting the input analog signal into a digital... |
| 4727579 |
Scrambled television signals |
| Feb-23-1988 |
A television receiver for receiving scrambled television signals has an arrangement (3) which provides scrambled video components (V) and packet arranged sound/data components (D) some of which are also... |
| 4700387 |
Broadcast system for scrambled programming signals |
| Oct-13-1987 |
A pay program signal is scrambled in an exclusive OR circuiit by a scrambling signal (Ks) derived from a random number generator. The pay program signal is converted into a broadcasting signal by a converter.... |
| 4659875 |
Electronic system for the secret transmission of audio signals |
| Apr-21-1987 |
System for the secret transmission of audio signals having at one end a coding arrangement comprising an input low-pass filter which selects the secret audio signals to be transmitted, two parallel signal... |
| 4654480 |
Method and apparatus for synchronizing encrypting and decrypting systems |
| Mar-31-1987 |
A synchronization method and corresponding apparatus for transmitting or storing encrypted data breaks the data into blocks and appends to each block an error detection code which is calculated from the... |
| 4645871 |
Non-interfering in-band protocol-independent diagnostic scanning in a digital multipoint communication system |
| Feb-24-1987 |
In a system in which data between a master and remote location is encrypted by using the DES algorithm, the status of security devices at the remote location is monitored from a centralized security station.... |
| 4642424 |
Cryptographic transmission system |
| Feb-10-1987 |
In a cryptographic communication system, a first encryptor transmits to a first decryptor and a second encryptor, co-located with the first decryptor, transmits to a second decryptor, which is co-located... |
| 4639548 |
Digital communication system including an error correcting encoder/decoder and a scrambler/descrambler |
| Jan-27-1987 |
An error correction code data communication system scrambles and descrambles both non-coded data and coded data by using substantially the same code process at the opposite ends of a transmission path.... |
| 4628358 |
Television signal encryption system with protected audio |
| Dec-9-1986 |
An encrypted video distribution system includes a signal-originating head end for scrambling the audio portion of outgoing television program-bearing signals. In particular, the audio content of a television... |
| 4613901 |
Signal encryption and distribution system for controlling scrambling and selective remote descrambling of television signals |
| Sep-23-1986 |
A system and method for scrambling and selectively descrambling television signals that are transmitted to subscribers' descramblers in a subscription television system. A working key signal is generated... |
| 4598318 |
Video encryption system |
| Jul-1-1986 |
An encrypted video distribution system includes a signal-originating head end for scrambling outgoing television program-bearing signals. In particular, the video content of selected lines is inverted... |
| 4577059 |
Decoding process and apparatus |
| Mar-18-1986 |
A decoding system containing a synchronizing and entry detector rendering possible the phase-in of messages delayed, for example, by interference. In order to be able to decode parts of the message received... |
| 4509093 |
Electronic locking device having key and lock parts interacting via electrical pulses |
| Apr-2-1985 |
Disclosed is an electronic locking device including electrically interacting key part and lock part each including electronic data processor with an inner code which is particular for a pair of key and... |
| 4484027 |
Security system for SSTV encryption |
| Nov-20-1984 |
In a secure communications system, a key number which is changed periodically, e.g. monthly, and a random number from a random number generator are combined and used as a seed to reset a PN sequence generator,... |
| 4389671 |
Digitally-controlled analog encrypton |
| Jun-21-1983 |
An apparatus for scrambling a television signal in which horizontal lines of the transmitted television picture are selectively inverted in accordance with the state of a pseudorandom noise generator.... |
| 4341925 |
Random digital encryption secure communication system |
| Jul-27-1982 |
A new and improved secure communication system is provided. A product code, formed from two pseudorandom sequences of digital bits, is used to encipher or scramble data prior to transmission. The two pseudorandom... |
| 4322576 |
Message format for secure communication over data links |
| Mar-30-1982 |
Communication over data links using binary synchronous protocol that is to be made secure according to the Federal data encryption standard (DES) is enhanced by utilizing an encrypted message format wherein... |
| 4310720 |
Computer accessing system |
| Jan-12-1982 |
A communications link between a computer and a remote user is effected by a portable access unit which generates a nonrecurring access code which is a function of a password and a pseudorandomly generated... |
| 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... |
| 4195196 |
Variant key matrix cipher system |
| Mar-25-1980 |
This is a cipher system for enciphering a stream of binary data by means of a product cipher. A clear message represented in a binary data format is transformed into a cipher message by operating on each... |
| 4169212 |
Multi-mode digital enciphering system |
| Sep-25-1979 |
The specification discloses an electronic digital enciphering system which is selectively operable in a plurality of different modes. The system may be operated in an off-line mode for preparing enciphered... |
| 4145569 |
Method and apparatus for synchronizing the ciphering and deciphering of binary-coded messages |
| Mar-20-1979 |
1. A method of ciphering and deciphering binary coded messages represented by coded series of pulses comprising setting a first pulse generator to an initial condition as defined by a secret basic code... |
| 4079195 |
Method and apparatus for the synchronization of a deciphering device functioning as a receiver with an enciphering device functioning as transmitter |
| Mar-14-1978 |
A method of, and apparatus for, the synchronization of a deciphering device operating as a receiver with an enciphering device operating as a transmitter, wherein at the transmitter end between information... |
| 4071693 |
Method and apparatus for synchronizing a receiver end-key generator with a transmitter end-key generator |
| Jan-31-1978 |
A method of, and apparatus for, synchronizing a receiver end-Key Generator with a transmitter end-Key Generator wherein both Key Generators are coupled with a respective counter such that each counter... |
