| 5222136 |
Encrypted communication system |
| Jun-22-1993 |
A system for exchanging encrypted data between selected devices at stations comprising a network. The system includes an encrypted communications device (ECOM) (12) that selectively encrypts data from... |
| 5220606 |
Cryptographic system and method |
| Jun-15-1993 |
I present a cryptographic communications system and method. The system includes a communications channel that is coupled to an encryption device and to a decryption device. A sender's plaintext message... |
| 5214698 |
Method and apparatus for validating entry of cryptographic keys |
| May-25-1993 |
A cryptographic facility implements a multiple key part import procedure. The installation manager can verify that a key part has been correctly entered and has not been compromised. The security requirement... |
| 5208858 |
Method for allocating useful data to a specific originator |
| May-4-1993 |
The hash result of useful data is transmitted to a multiply-protected central server in which it is transformed into a signature on the basis of a crypto operations system combination with a private key... |
| 5195136 |
Method and apparatus for data encryption or decryption |
| Mar-16-1993 |
A cryptographic apparatus comprises a linear feedback shift register for providing a pseudo-random code, coupled to a ciphering device, which is in turn coupled to an adder. The ciphering device encrypts... |
| 5195133 |
Apparatus and method for producing a digitized transaction record including an encrypted signature |
| Mar-16-1993 |
A method and system for generating a completed payment document ready for signature in image form. The document is signed by a customer and a copy of the signature is captured in digital form. Thereafter... |
| 5164986 |
Formation of rekey messages in a communication system |
| Nov-17-1992 |
Formation and sending of rekeying messages (305, 415, 515, and 605) in an encrypted communication system with over-the-channel rekeying of communication units is performed by a KMC, key management controller... |
| 5161244 |
Cryptographic system based on information difference |
| Nov-3-1992 |
The cryptographic system is comprised of two stations A and B in which a respective string S.sub.A and S.sub.B of digits is stored. In station A an error-control information string C is generated from... |
| 5161189 |
Encryption and decryption of chained messages |
| Nov-3-1992 |
A single sync field (501) and multiple messages or message segments (503, 507, 511, and 515) are chained (407) together and encrypted (407) as a whole. When this encrypted chained message is received,... |
| 5159633 |
Multimedia network system |
| Oct-27-1992 |
There is disclosed a multimedia network system for transmitting real-time communication type information such as a television video signal and storage type information such as a computer file using at... |
| 5151938 |
Security enhancement in a data processor through use of dynamic parameter authentication |
| Sep-29-1992 |
A descrambler for descrambling scrambled information signals through use of a predetermined decryption key. The processing means are adapted for processing data in accordance with a number of different... |
| 5150412 |
Security module for radio telephone |
| Sep-22-1992 |
A security module for a radio telephone prevents a KEY code stored in a non-volatile memory from being read out for illicit use. The security module deletes the KEY code stored in the memory when accessed... |
| 5144664 |
Apparatus and method for upgrading terminals to maintain a secure communication network |
| Sep-1-1992 |
A secure communication network serves a plurality of terminals grouped into different security categories. Each terminal includes a replaceable security element containing a security algorithm specific... |
| 5142579 |
Public key cryptographic system and method |
| Aug-25-1992 |
A public key cryptographic system and method includes an insecure communications channel connecting at least two communicating complexes, a sender and a receiver. The sender possesses an encoding device... |
| 5134656 |
Pre-payment television system using a memory card associated with a decoder |
| Jul-28-1992 |
According to the invention, on the emitter side, a number generator (10) delivers a random code (XAL) which is sent to the input of a master card (11) which ciphers such code according to a predetermined... |
| 5125028 |
Television signal scrambling method and apparatus |
| Jun-23-1992 |
A television scrambling system of the GSS type includes a false key signal to defeat pirate decoders. The false key is placed approximately one half a horizontal line period following the last horizontal... |
| 5103478 |
Secure management of keys using control vectors with multi-path checking |
| Apr-7-1992 |
A requested cryptographic function is validated for performance in conjunction with a cryptographic key, by inputting a first portion of an associated control vector into a first control vector checker,... |
| 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... |
| 5091941 |
Secure voice data transmission system |
| Feb-25-1992 |
In the secure radio transmission system of the present invention the sign bit for each byte of audio digital data is scrambled to generate a scrambled sign bit. By altering the sign bit, the resultant... |
| 5086468 |
Text modifier |
| Feb-4-1992 |
A method is disclosed and apparatus is described whereby plain text is modified before it is input to a binary key generator (encryptor). According to the invention, a plain text bit may be modified by... |
| 5081679 |
Resynchronization of encryption systems upon handoff |
| Jan-14-1992 |
A system for the synchronization of encryption and decryption in a duplex cellular radio system in which an encrypted call may be switched from one cell to another. At the instant of handoff, a rapid first... |
| 5073935 |
Method for secure communication |
| Dec-17-1991 |
A method for the secure communication of messages. A first party is provided with a set of numbers that have the property that when encrypted using an RSA encryption key the resulting set of encrypted... |
| 5068895 |
Encryption and decryption methods using bit-length preservation decryptor |
| Nov-26-1991 |
An encrypting method for producing a code which cannot be deciphered by an eavesdropper. The encrypting method does not require the bit length of input information to be increased when the information... |
| 5048087 |
Key management for encrypted packet based networks |
| Sep-10-1991 |
In a packet based communication network 10, a key management center 20 is used to distribute cryptographic keys for either a switched virtual circuit or a permanent virtual circuit. The disclosed methods... |
| 5016275 |
Buffered encryption/decryption |
| May-14-1991 |
Encryption and decryption mechanisms at transmitters and receivers, respectively, have applied thereto encryption or decryption keys and initializing values. These mechanisms generate cryptographic bit... |
| 5014314 |
Method for developing and transmitting usage context information in an RF communication system |
| May-7-1991 |
In an RF communication system, a method for developing and communicating usage context information. When an inbound communication (110) is received from a communication unit (107), a repeater (101) at... |
| 5008938 |
Encryption apparatus |
| Apr-16-1991 |
An encryption circuit that operates with substantially zero delay. Using programmable keys and polynomials, the encryption algorithm can be constantly changed to thwart any unintended receiving parties... |
| 5003596 |
Method of cryptographically transforming electronic digital data from one form to another |
| Mar-26-1991 |
A cryptographic system creates a key table from a single key such that the relationship between the keys in the key table cannot be determined even if the system implementation is known. The system uses... |
| 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... |
| 4984270 |
Method and system for transmission of financial data |
| Jan-8-1991 |
An improved system for transmission financial data includes, in preferred embodiments, an encryption key stored on a bank card and used to encrypt preselected data prior to transmission. Encrypted data... |
| 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... |
| 4969190 |
Encrypting system of data |
| Nov-6-1990 |
A data encrypting system according to the CBC system involves a limitation in a range of a numerical value which expresses data (smaller than a predetermined integer N). The encrypting system has an encrypting... |
| 4944006 |
Secure data packet transmission system and method |
| Jul-24-1990 |
A bit packet communication system includes a head-end having a software implemented 16 bit shift register with a plurality of feed-forward taps and a different plurality of feedback taps for simultaneously... |
| 4926478 |
Method and apparatus for continuously acknowledged link encrypting |
| May-15-1990 |
An authentication system in which communication between two locations is provided by a continuous full duplex bidirectional communications highway, which highway is a secure link between the two locations.... |
| 4924513 |
Apparatus and method for secure transmission of data over an unsecure transmission channel |
| May-8-1990 |
Apparatus and methods, readily adapted to interface with a standard data transmission network having an unsecure transmission channel, e.g., "Ethernet," for the provision of secure transmission of data... |
| 4897876 |
Method of and an arrangement for digital signal encryption |
| Jan-30-1990 |
An improved arrangement for digital signal encrytion using a cipher algorithm in which a multi-bit key signal is used to produce a first keystream signal of coding bytes which are used in an exclusive-OR... |
| 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... |
| 4890324 |
Enciphering/deciphering method and arrangement for performing the method |
| Dec-26-1989 |
A key stream is generated, and successive keys and instruction words are derived from it. A character is enciphered with a derived key by an enciphering operation determined by the instruction word. A... |
| 4881263 |
Apparatus and method for secure transmission of data over an unsecure transmission channel |
| Nov-14-1989 |
Apparatus and methods, readily adapted to interface with a standard data transmission network having an unsecure transmission channel, e.g., "Ethernet," for the provision of secure transmission of data... |
| 4876718 |
Secure data packet transmission system and method |
| Oct-24-1989 |
A bit packet communication system includes a head-end having a software implemented 16 bit shaft register with a plurality of feed-forward taps and a different plurality of feed-back taps for simultaneously... |
| 4870612 |
Operator console with paired modules including means for ciphering and deciphering messages therebetween based on a mutually known, exclusive internal security code |
| Sep-26-1989 |
An operator console for data communication is divided into two separate units which can be connected electrically together, namely a keyboard (10) having a logical unit (21), with a memory (211) and a... |
| 4852166 |
Analogue scrambling system with dynamic band permutation |
| Jul-25-1989 |
An analogue scrambling system with dynamic band permutation in which the speech signal is filtered (1), sampled (2) at the rate f.sub.e, digitized (3), transformed by means of an analysis filter bank (4)... |
| 4817144 |
Secure TV scrambling system using framing code switching |
| Mar-28-1989 |
A television signal scrambling system scrambles by suppressing horizontal syncs and changing the phase of the video carrier during the horizontal intervals. Data is transmitted by using two different widths... |
| 4815130 |
Stream cipher system with feedback |
| Mar-21-1989 |
A cipher system in which a key is initially inserted into a shift register and the serial output of the shift register is added to the plain text message and the sum is fed back into the serial input of... |
| 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... |
| 4803726 |
Bit synchronization method for a digital radio telephone system |
| Feb-7-1989 |
A method and means for maintaining continuous bit synchronization of data transmitted from a remote unit through a base unit to a landline unit is disclosed. An input data stream at a first bit rate, such... |
| 4783799 |
Electronic communications and control system |
| Nov-8-1988 |
A fully distributed, disposable, self-organizing, independently powered communications system is described capable of providing a radio-communications channel in environments that may prove dangerous or... |
| 4771458 |
Secure data packet transmission system and method |
| Sep-13-1988 |
A bit packet communication system includes a head end having a software implemented 16 bit shift register with a plurality of feed-forward taps and a different plurality of feedback taps for simultaneously... |
| 4763357 |
Method and apparatus for providing secure electronic communications |
| Aug-9-1988 |
A method and apparatus for providing secure electronic communications over a communications medium between first and second locations is disclosed. A data device for generating and/or receiving data is... |
| 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... |
