Abstract:
The following describes an apparatus for and method of providing a secure method of downloading a program into a processor (101) from a device (103) external to the processor (101). The program may be encrypted (207) prior to its entry into the external device (103). The program may also have authentication information added (203 and 207) to it. Authentication information may be provided on an unencrypted and/or an encrypted program. The processor (101) decrypts (307) and/or successfully authenticates (311) the program before allowing the program to be executed by the processor (101).
Abstract:
A cryptographic apparatus for encrypting and decrypting digital words includes a mechanism that permits a cipher algorithm to be electronically stored after the manufacture of the apparatus. The storing mechanism includes at least one electrically erasable, programmable gate array containing a portion of the cipher algorithm and at least one random access memory device coupled to the array for storing digital data generated by the algorithm. A mechanism which is coupled to the gate array and memory device controls the execution of the algorithm for each digital word thereby decrypting encrypted digital words and encrypting non-encrypted digital words.
Abstract:
A detector (200) locates a shift register sequence (408) within a digital data stream by correlating the data stream with a sequence (356) generated locally from a portion of the data stream. Error correction circuitry (100) estimates errors that may have corrupted the sequence during transmission across a noisy channel (416) and corrects them to the extent possible. The data stream and local sequence are correlated during an interval that is shifted either ahead (336) or behind (336') the portion of the error-corrected data stream (304) used to initialize the local sequence generator (302), thereby avoiding the region during which short-term correlation between the data stream and local sequence would otherwise cause false indications of detection when only noise or random data is being received.
Abstract:
Roaming encryption key rekeying apparatus and method comprising a first system key management facility that communicates to a communication unit roaming information is disclosed. The roaming information is encrypted using a first encryption scheme that is decipherable by the communication unit. Further, the first system key management facility communicates to a second system key management facility the roaming information. In this communication, the roaming information is encrypted as a function of a second encryption scheme that is decipherable by the second system key management facility.
Abstract:
A method for managing a packet in a communication system between two or more endpoints, a sender and one or more recipients, comprises receiving a first packet comprising a source identifier that uniquely identifies a sender of the first packet and a current source time assigned to the first packet by the sender, determining a received time for the first packet, retrieving a cached source time assigned by the sender to a second packet that was received prior to receiving the first packet, and determining whether to discard or process the first packet based on the current source time, the received time, and the cached source time. The current source time, the received time, and the cached time, in addition to predetermined parameters such as a maximum age and an anti-replay window allows a recipient to determine whether to process or discard a packet.
Abstract:
Disclosed is a method for encrypted communications. A first IPsec endpoint selects a security association (SA) from a security association database (SAD) by using a selector and then extracts an indexing parameter from SA. The indexing parameter is used to determine an active key location from a key storage database (KSD). Data packets are then encrypted using a key from the active key location. The first IPsec endpoint also forms a security parameter index (SPI) in a header of the data packet by using a keyID from the active key location and transmits the encrypted data packet with the header indicating the SPI to a second IPsec endpoint.
Abstract:
Se describe un método para comunicaciones encriptadas. Un primer punto terminal de IPsec selecciona una asociación de seguridad (SA - security association) a partir de una base de datos de asociación de seguridad (SAD - security association database) utilizando un selector y después extrae un parámetro de indexación de la SA. El parámetro de indexación se utiliza para determinar una ubicación de clave activa proveniente de una base de datos de almacenamiento de claves (KSD - key storage database). Los paquetes de datos se encriptan después utilizando una clave proveniente de la ubicación de claves activas. El primer punto terminal de IPsec forma también un índice de parámetro de seguridad (SPI - security parameter index) en una cabecera del paquete de datos utilizando una keyID (ID de clave) proveniente de la ubicación de claves activas y transmite el paquete de datos encriptados con la cabecera indicándole el SPI a un segundo punto terminal de IPsec.
Abstract:
Disclosed is a method for encrypted communications. A first IPsec endpoin t selects a security association (SA) from a security association database ( SAD) by using a selector and then extracts an indexing parameter from SA. Th e indexing parameter is used to determine an active key location from a key storage database (KSD). Data packets are then encrypted using a key from the active key location. The first IPsec endpoint also forms a security paramet er index (SPI) in a header of the data packet by using a keyID from the acti ve key location and transmits the encrypted data packet with the header indi cating the SPI to a second IPsec endpoint.
Abstract:
The following describes an apparatus for and method of providing a secure method of downloading a program into a processor (101) from a device (103) external to the processor (101). The program may be encrypted (207) prior to its entry into the external device (103). The program may also have authentication information added (203 and 207) to it. Authentication information may be provided on an unencrypted and/or an encrypted program. T he processor (101) decrypts (307) and/or successfully authenticates (311) the program before allowing the program to be executed by the processor (101).