| 5675734 |
System for transmitting desired digital video or audio signals |
| Oct-7-1997 |
A method for transferring desired digital video or digital audio signals. The method comprises the steps of forming a connection through telecommunications lines between a first memory of a first party... |
| 5675652 |
Computer readable device implementing a software-efficient pseudorandom function encryption |
| Oct-7-1997 |
A software-efficient pseudorandom function maps an index and an encryption key to a pseudorandom bit string useful for constructing a stream cipher. The method begins by preprocessing the encryption key... |
| 5671283 |
Secure communication system with cross linked cryptographic codes |
| Sep-23-1997 |
A cryptographic communications system includes a method and apparatus for sending and receiving a plurality of encrypted signal packets in a system for metering the use of encrypted information. Plural... |
| 5666421 |
Mail processing system including data center verification for mailpieces |
| Sep-9-1997 |
A system for controlling the validity of printing of indicias on mailpieces from a potentially large number of users of postage meters includes apparatus disposed in each said postage meter for generating... |
| 5655021 |
Method for checking data sequences |
| Aug-5-1997 |
The invention relates to a method for checking data sequences, comprising a protection step and a verification step, with a control sequence being formed in the protection step on the basis of an identification... |
| 5652796 |
Data encryption control system |
| Jul-29-1997 |
The data encryption system includes a first stage and a second stage data encryption engine in combination with a micro control system. The data encryption system is responsive to control signals from... |
| 5638448 |
Network with secure communications sessions |
| Jun-10-1997 |
A system which uses three way password authentication, and s.sup.3 DES to encrypt different portions of a logon packet with different keys based on the nature of the communications link. Nodes attached... |
| 5625642 |
Spread-response precoding system having signature sequences longer than the inter-symbol time interval |
| Apr-29-1997 |
Method and apparatus for preparing a message stream of symbols for wireless transmission by pre-coding it through convolution with a characteristic "signature" of predetermined symbols identifying a particular... |
| 5594797 |
Variable security level encryption |
| Jan-14-1997 |
A method and apparatus for digital cellular telephone encryption includes a switch when a choice between compatibility security and a higher security is required. Plaintext is converted into ciphertext... |
| 5572193 |
Method for authentication and protection of subscribers in telecommunications systems |
| Nov-5-1996 |
A method and apparatus for authentication between a subscriber unit and a communication unit is provided. The authentication process includes: maintaining an historic non-arbitrary value in the subscriber... |
| 5555256 |
Channel identifier generation |
| Sep-10-1996 |
A method and arrangement are disclosed for generating a cell-channel identifier ("master VCN") for cells received through at least one input port of an apparatus intended to carry out predetermined functions... |
| 5546464 |
Method of and apparatus for selective resynchronization in a digital cellular communications system |
| Aug-13-1996 |
In a ciphered digital cellular communications system a method and apparatus are presented for selective resynchronization of the cipher upon initial channel acquisition or handoff. Where synchronization... |
| 5528230 |
Remote control transmitter/receiver system |
| Jun-18-1996 |
A remote control transmitter/receiver system in which a transmitter transmits a signal incorporating a secret code and a command function. The receiver receives the signal from the transmitter, discriminates... |
| 5502575 |
Imaging apparatus having a counterfeiting prevention function |
| Mar-26-1996 |
An imaging apparatus comprising a counterfeiting prevention arrangement and reliably preventing counterfeit reproduction of currency, negotiable certificates, and other registered documents is provided... |
| 5500898 |
Scramble communication system multiplexing/demultiplexing scramble generation polynomial |
| Mar-19-1996 |
A scramble communication system comprises a station and a plurality of terminals connected to the station. The respective terminals are previously provided with specific scramble generation polynomials... |
| 5488658 |
Video signal scrambling and descrambling apparatus |
| Jan-30-1996 |
A common circuit is used for scrambling and descrambling video signals. A memory stores key data. During scrambling the output of the memory is transmitted to a read address counter through an address... |
| 5483598 |
Message encryption using a hash function |
| Jan-9-1996 |
An encryption system employing a one-time key-pad uses a shared secret number and a one-way hash function with which both the originator and recipient of a message generate successive segments of a key-pad... |
| 5455864 |
Encrypted paging message transmission |
| Oct-3-1995 |
A method and apparatus for paging message encryption and decryption is shown and described. Paging messages may be encrypted at their source or by the paging system and delivered by radio signal in secure... |
| 5448641 |
Postal rating system with verifiable integrity |
| Sep-5-1995 |
A data center provides a rate table to a user. The rate table is communicated to the mailer along with a hash code that is based on information from the rating table. The hash code provides a unique number... |
| 5438621 |
DC-free line code and bit and frame synchronization for arbitrary data transmission |
| Aug-1-1995 |
A method of encoding data for transmission over a communication link. A cumulative polarity of previously-transmitted frames is maintained. A frame is prepared for transmission by combining a data word... |
| 5420866 |
Methods for providing conditional access information to decoders in a packet-based multiplexed communications system |
| May-30-1995 |
In a packet-based multiplexed communications system, a method of providing different sets of conditional access information to a remote location comprises the steps of: (a) for each different set of conditional... |
| 5381481 |
Method and apparatus for uniquely encrypting a plurality of services at a transmission site |
| Jan-10-1995 |
Methods and apparatus are described for uniquely encrypting a plurality services at a transmission site and for decrypting selected services at a reception site while reducing the amount of encryption... |
| 5365589 |
Method and apparatus for encryption, decryption and authentication using dynamical systems |
| Nov-15-1994 |
A method and apparatus provide encryption, decryption and authentication of messages using dynamical systems. The method and apparatus preferably operate on an information stream which may comprise message... |
| 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... |
| 5357571 |
Method for point-to-point communications within secure communication systems |
| Oct-18-1994 |
In a secure communication system, a secure point-to-point communication may be accomplished in the following manner. A first communications unit receives a request from an operator for a point-to-point... |
| 5355415 |
Parallel distributed sample scrambling system |
| Oct-11-1994 |
A parallel distributed sample scrambling and descrambling system for fixed-sized packet transmission comprising a parallel scrambler and a parallel descrambler. The scrambler includes; a parallel shift... |
| 5355409 |
Scramble codec and a television receiver incorporating the same |
| Oct-11-1994 |
A scramble codec comprises a latch means for holding an ID number for securing television or other communication data, a pair of memories which can be alternately loaded with input communication data signals... |
| 5353351 |
Secure teleconferencing |
| Oct-4-1994 |
Secure teleconferencing between three or more parties is achieved by receiving encrypted information streams from each of the parties to the conference. The encrypted information streams are received in... |
| 5341426 |
Cryptographic key management apparatus and method |
| Aug-23-1994 |
A method for establishing a secure communications link between first and second terminals includes a step of exchanging a first message. The first message contains information describing encryption devices... |
| 5325433 |
Encryption communication system |
| Jun-28-1994 |
An encryption communication system including: a communication center having at least a key information generating unit for generating key generating information used for encryption communication; and a... |
| 5319705 |
Method and system for multimedia access control enablement |
| Jun-7-1994 |
A method and system are disclosed for securely distributing a plurality of software files from a software distribution processor to a user processor, while selectively enabling the user processor to only... |
| 5301247 |
Method for ensuring secure communications |
| Apr-5-1994 |
A method for initiating secure communications between two stations. In this method, a first portion of a session data encryption key (DEK1) is randomly generated by an EDU in one of the stations. The DEK1... |
| 5301234 |
Radiotelephone installation for prepayment operation with security protection |
| Apr-5-1994 |
In the course of the intercommunication between the base station and the autonomous telephone set, the first means of authentication initially generates a keyword dependent on the call charge for the current... |
| 5283831 |
Method of synchronizing the pseudo-random binary sequence in a descrambler |
| Feb-1-1994 |
In a data communication system a signal is coded with n-bit codewords, wherein n is an integer. The codewords are converted to a serial bit-stream and scrambled using a PRBS (Pseudo-Random Binary Sequence)... |
| 5283806 |
Method of sequencing signal processing in the communication mode of a digital cellular radio system |
| Feb-1-1994 |
In a method of sequencing signal processing in the communication mode of a digital cellular radio system for conveying digitized speech communications between a terminal and a base station by means of... |
| 5278906 |
System for encoding data presented with a first coding device and for decoding encoded data with a second coding device, and coding device for use in the system |
| Jan-11-1994 |
In a system for de-/encoding data using (de)coding devices at either end of a transmission channel, the data sometimes comprise additional synchronisation information which is used to reduce the effect... |
| 5272755 |
Public key cryptosystem with an elliptic curve |
| Dec-21-1993 |
The present invention provides a public key cryptosystem with an elliptic curve which comprises the steps of informing public data, selecting first and second privacy keys at the end of first and second... |
| 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... |
| 5253296 |
System for resisting interception of information |
| Oct-12-1993 |
A time segment scrambling information encoding and decoding system wherein a multiplicity of scrambling algorithms are stored in a memory such as a ROM for use during transmission via a chosen medium and... |
| 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... |
| 5241597 |
Method for recovering from encryption key variable loss |
| Aug-31-1993 |
A method for recovering from encryption key variable loss, either inadvertent or the result of tampering. A predetermined key encryption key is encrypted with itself at the time when keys are first loaded,... |
| 5241595 |
Communication control section for facsimile equipment having a secure communication function |
| Aug-31-1993 |
A facsimile equipment including a memory for storing a cipher key data, ten number keys for inputting the cipher key data, a DTMF signal receiving circuit for converting a DTMF signal received through... |
| 5239294 |
Method and apparatus for authenication and protection of subscribers in telecommunication systems |
| Aug-24-1993 |
Radio frequency based cellular telecommuication systems often require a subscriber (10) to maintain a proprietary identifier (19) or serial number (18) which is transmitted to a fixed network communication... |
| 5237612 |
Cellular verification and validation system |
| Aug-17-1993 |
A system for the validation and verification of base stations and mobile stations within a cellular radio communications network. The system includes a fixed key and a changeable key which are applied... |
| 5237593 |
Sequence synchronisation |
| Aug-17-1993 |
A first (receiver), for example, pseudo random binary sequence (PRBS) generator (6) is synchronized with a second identical PRBS generator (2) at a tramsitter by adding a PRBS (u(x)) to a data stream (w(x)).... |
| 5233653 |
Apparatus and method for enciphered facsimile transmission and reception |
| Aug-3-1993 |
An enciphered facsimile apparatus in which encoded image data is fetched one block at a time, and chained encipherment is executed in a reverse direction, respectively. Upon completion of encipherment,... |
| 5230019 |
Key signal conversion device for CATV system |
| Jul-20-1993 |
A key signal conversion device for use in a CATV television system in which more than one different scrambling process is performed, the conversion device receiving one of a scrambled high-frequency signal... |
| 5224166 |
System for seamless processing of encrypted and non-encrypted data and instructions |
| Jun-29-1993 |
A data processing system includes an internal cache memory in a secure physical region that is not accessible to a user of the system. An external memory is positioned outside of the secure physical region... |
| 5222137 |
Dynamic encryption key selection for encrypted radio transmissions |
| Jun-22-1993 |
A radio (100) transmits and receives encrypted signals having unencrypted key identifiers, allowing other radios having the corresponding key identifiers and encryption keys to communicate with radio (100).... |
