| 5740251 |
Data processing apparatus |
| Apr-14-1998 |
A block processing section divides message data into a plurality of blocks, so as to obtain a plurality of data blocks. A plurality of data encryption processing sections are provided in correspondence... |
| 5719939 |
System and method of verifying the legitimacy of a product against forgery |
| Feb-17-1998 |
A product, such as a credit card, passport, or bank note, is secured against forgery or fraud by the provision of a unique pattern of overlying individual fibers which are embedded in a transparent base... |
| 5715315 |
CATV systems |
| Feb-3-1998 |
A CATV system including a CATV network, multiplicity of subscriber units, apparatus for transmitting over said CATV network encrypted information individually addressed to a subscriber unit and apparatus... |
| 5682425 |
Information signal transmission system |
| Oct-28-1997 |
The information signal transmission system of the present invention is so designed as to convert the analog information signal into digital information data and to transmit these digital data after enciphering... |
| 5680452 |
Distributed cryptographic object method |
| Oct-21-1997 |
A system for increasing the security of a computer system, while giving an individual user a large amount of flexibility and power. To give users the most power and flexibility, a standard object that... |
| 5642421 |
Encryption of low data content ATM cells |
| Jun-24-1997 |
The security provided by encryption of ATM cells is enhanced by testing each cell for low data content level. If a cell has a low data content, its contents are nevertheless compressed and the resulting... |
| 5621794 |
Moving-picture encipherment method and system, and enciphered moving-picture decipherment method and system |
| Apr-15-1997 |
Moving-picture data in a frame is encoded without depending on another frame of moving-picture data, and moving-picture data in a frame is encoded depending on another frame of moving-picture data. Whether... |
| 5606612 |
Method and apparatus for television signal scrambling using a line expansion technique |
| Feb-25-1997 |
A method and apparatus for scrambling an original analog video signal samples predetermined portions of the original video signal at a first rate and stores the sampled portions of the original video signal... |
| 5596640 |
Digital image forming apparatus with data conversion |
| Jan-21-1997 |
An image forming apparatus including an operating board for indicating operating modes, a document reading member and an outputting member for outputting data. An image compressing member compresses image... |
| 5592555 |
Wireless communications privacy method and system |
| Jan-7-1997 |
A method and system for privately communicating signals over a wireless communications network include the steps of and circuitry and instructions for processing communication signals in a first signal... |
| 5590195 |
Information dissemination using various transmission modes |
| Dec-31-1996 |
A system and method of information dissemination that permits the user to listen to the specific content of information when and where he or she wants to. A radio or television receiver system receives... |
| 5583938 |
Image signal scrambling apparatus and descrambling apparatus |
| Dec-10-1996 |
An object of the invention is to provide an image scrambling apparatus and an image descrambling apparatus capable of making a communication of secrecy by scrambling a digital image signal as well as variable-length-encoding... |
| 5524134 |
Telecommunications security module |
| Jun-4-1996 |
A security module for use in a cellular telephone provides for low power consumption. The security module includes a vocoder processor for manipulating signals from the telephone's microphone and to the... |
| 5524051 |
Method and system for audio information dissemination using various modes of transmission |
| Jun-4-1996 |
A system and method of information dissemination that permits the user to listen to the specific content of information when and where he or she wants to. A radio or television receiver system receives... |
| 5504816 |
Method and apparatus for controlling access to digital signals |
| Apr-2-1996 |
A method and apparatus are provided for controlling access to digital signals sent via a first communication path and retransmitted over a second communication path. The digital signals, having been encrypted... |
| 5479512 |
Method and apparatus for performing concryption |
| Dec-26-1995 |
A method and apparatus for the integrated compression and encryption (concryption) of clear data and for the deconcryption of concrypted data to obtain the clear data for utilization. For concryption,... |
| 5426699 |
Method and apparatus for digitizing a scrambled analog video signal |
| Jun-20-1995 |
An on demand services feature for the provision of video, audio, and data services for a subscription system of the CTV type, or the like. The system comprises a headend coupled to a distribution network... |
| 5420923 |
Addressed messaging in a cable television system |
| May-30-1995 |
A method of transmitting addressed messages to subscribers comprises the steps of defining the group or individual subscriber to be addressed, creating the message, assigning the message to the individual... |
| 5410599 |
Voice and data encryption device |
| Apr-25-1995 |
A portable voice and data encryption device designed to be used with normal wideband telephone and cellular telephones, computers and facsimile machines to transmit voice and data in encrypted form. The... |
| 5398283 |
Encryption device |
| Mar-14-1995 |
A system for the encryption of documents is described. A document, which may contain not only text, but also handwriting, pictures, charts, or other graphic images, is converted into a bitmap. This bitmap... |
| 5347650 |
Device for transforming a digital data sequence into a condensed digital data block using tables and logic operators |
| Sep-13-1994 |
An electronic device for processing digital data has an input for receiving data to be processed and processor means suitable for transforming the input data in non-falsifiable manner into a result condensed... |
| 5321749 |
Encryption device |
| Jun-14-1994 |
A system for the encryption of documents is described. A document, which may contain not only text, but also handwriting, pictures, charts, or other graphic images, is converted into a bitmap. This bitmap... |
| 5307413 |
Method and apparatus for adding data compression and other services in a computer network |
| Apr-26-1994 |
A connection specific compression system is selectively implemented in connections having the greatest data redundancy and utilizes modularity in implementing data compression in a layered network communication... |
| 5285497 |
Methods and apparatus for scrambling and unscrambling compressed data streams |
| Feb-8-1994 |
Methods and apparatus for encoding compressed data streams efficiently, and methods and apparatus for decoding the encrypted data streams efficiently and inexpensively, are disclosed. In an encoder 10',... |
| 5235641 |
File encryption method and file cryptographic system |
| Aug-10-1993 |
In an information processing system having an upper rank apparatus and an external storage device which performs transmission and reception of data between the storage device and the upper rank apparatus,... |
| 5020104 |
Method of reducing the useful bandwidth of bandwidth-limited signals by coding and decoding the signals, and system to carry out the method |
| May-28-1991 |
The useful bandwidth of a bandwidth-limited input signal (s(t)) is reduced, to obtain a coded signal (q(t)) by forming a combined input and feedback signal, low-pass filtering the combined signal, and... |
| 4956808 |
Real time data transformation and transmission overlapping device |
| Sep-11-1990 |
A real time data transformation and transmission apparatus transforms data from a first data device and transfers the transformed data to a second data device which need not have a data transfer rate consistent... |
| 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... |
| 4817146 |
Cryptographic digital signal transceiver method and apparatus |
| Mar-28-1989 |
Hybrid subband coding and decoding (using different encloding/decoding algorithms in at least one subband channel) and subband time delay compensation at a point of maximum digital bandwidth compression... |
| 4817141 |
Confidential communication system |
| Mar-28-1989 |
The respective feature parameters extracted from a speech signal is converted into the corresponding line spectrum data in a first frequency band obtained by dividing the speech signal frequency band.... |
| 4788543 |
Apparatus and method for broadcasting priority rated messages on a radio communications channel of a multiple transceiver system |
| Nov-29-1988 |
Apparatus in a transceiver for broadcasting priority rated messages on a channel shared by a multiplicity of similar transceivers, converts an analog audio frequency message to compressed digitalized format... |
| 4752953 |
Digital audio scrambling system with pulse amplitude modulation |
| Jun-21-1988 |
In a system for scrambling an audio signal for transmission with a video signal having non-video information intervals, an analog audio signal is converted into a scrambled compressed digital audio signal;... |
| 4688246 |
CATV scrambling system with compressed digital audio in synchronizing signal intervals |
| Aug-18-1987 |
A CATV television system has the sync and color subcarrier reference information replaced in the horizontal blanking intervals with compressed digital audio data. The digital audio data is in the form... |
| 4683586 |
Scrambling system for an audio frequency signal |
| Jul-28-1987 |
A scrambling system for an audio frequency signal is disclosed which employs a timebase-compressing and/or expanding system to measure the compressed and/or expanded amount of a segment time length caused... |
| 4581746 |
Technique for insertion of digital data bursts into an adaptively encoded information bit stream |
| Apr-8-1986 |
The present invention relates to a transmitter and a receiver for use in a digital communication system which are capable of transmitting and receiving, respectively, a single duplex analog signal channel,... |
| 4550222 |
Process for interception-protected frequency band compressed transmission of speech signals |
| Oct-29-1985 |
In order to achieve a good masking, together with minimum bandwidth requirement of sample values of spectral channels which are to be transmitted in the timing of consecutive analysis intervals in a time... |
| 4433211 |
Privacy communication system employing time/frequency transformation |
| Feb-21-1984 |
A privacy communication system digitizes a voice signal and divides the signal into different frequency bands or time segments and shifts the bands or segments in frequency and/or time under control of... |
| 4206315 |
Digital signature system and apparatus |
| Jun-3-1980 |
A digital signature machine provides a simplified method of forming and verifying a signature that is appended to a digital message. A sender transmits a signature with the usual signature keys and with... |
