Abstract: Modifying signals so that the signals are differentiated for spectral efficiency, including: modifying the signals wherein a first signal is correlated between first and second transmissions and a second signal is uncorrelated between the first and second transmissions; transmitting the first and second signals with time delays from a plurality of antennas; and receiving and finding a set of weights corresponding to the plurality of antennas, wherein correlation between two transmissions is maximized.

Abstract: Apparatus and method for provisioning an access key used for a controlled access broadcast service is disclosed. In one aspect, a method for secure processing in a device that securely stores a secret key comprises receiving a plurality of challenges from a network, generating a plurality of ciphering keys based on the secret key and the plurality of challenges, and generating an access key based on the plurality of ciphering keys.

Abstract: Security keys are typically needed to communicate with various network communication protocols of a mixed communication network. Herein, a protocol-specific key for a particular network communication protocol is generated based upon a result of a hash operation that includes a network key associated with the mixed communication network and information corresponding to the particular network communication protocol. Interoperability of multiple devices in the mixed communication network is made possible when the multiple devices generate (i.e. derive) protocol-specific keys using the same network key and common information corresponding to particular network communication protocols.

Abstract: The REX cryptosystem presented herein is a variant of the NTRU cryptosystem. In the REX cryptosystem, a primary ring RXOR and two secondary rings RXOR,q and RXOR,p are used to reduce the number of operations required to compute the keys, to perform the encryption process, and to perform the decryption process. The REX cryptosystem may also be implemented using Walsh-Hadamard transformations to significantly increase speed.

Abstract: A system and method for encrypting all channels of a wireless spread spectrum communication at the chip level. The PN sequence is encrypted with one or more encryption sequences and then used to spread the signal.

Abstract: Systems and methods for systems and methods for reliably broadcasting content to a plurality of users and facilitating distribution of portions of the broadcast content that either were not received by particular users, or were received with errors. In one embodiment, a wireless communication system is configured to broadcast content from a content source to a plurality of user devices. The content source is configured to provide the content to a base station. The base station parses the content into a plurality of segments and associates sequential identifiers with each of the segments. The content is then broadcast to each of the user devices. An identifier of an alternative data source is also provided to the user devices. When a mobile station receives the segments, it examines the segment identifiers to identify missing segments. The segments are then retrieved from the alternative data source identified by the base station.

Abstract: Systems and methods for systems and methods for reliably broadcasting content to a plurality of users and facilitating distribution of portions of the broadcast content that either were not received by particular users, or were received with errors. In one embodiment, a wireless communication system is configured to broadcast content from a content source to a plurality of user devices. The content source is configured to provide the content to a base station. The base station parses the content into a plurality of segments and associates sequential identifiers with each of the segments. The content is then broadcast to each of the user devices. An identifier of an alternative data source is also provided to the user devices. When a mobile station receives the segments, it examines the segment identifiers to identify missing segments. The segments are then retrieved from the alternative data source identified by the base station.

Abstract: A method and apparatus for optimizing registration and paging in a group communication system uses mobility of the participating mobile stations to minimize the number of registrations performed by the participating mobile stations as well as the area of paging the participating mobile stations. When the participating mobile stations have a low mobility status, the base station reduces the area of paging the mobile stations so that the paging channel load is reduced.

Abstract: The REX cryptosystem presented herein is a variant of the NTRU cryptosystem. In the REX cryptosystem, a primary ring RXOR and two secondary rings RXOR,q and RXOR,p are used to reduce the number of operations required to compute the keys, to perform the encryption process, and to perform the decryption process. The REX cryptosystem may also be implemented using Walsh-Hadamard transformations to significantly increase speed.

Abstract: A method, apparatus and system provide for efficient use of communication resources for providing broadcast services in a communication system. A receiver receives a first broadcast controller identification from a first base station, and a second broadcast controller identification from a second base station. A controller coupled to the receiver determines whether the first and second broadcast controller identifications are associated with use of a common set of broadcast parameters. A transmitter transmits a request for transmission of a new set of broadcast parameters when the first and second broadcast controller identifications are not associated with use of the common set of broadcast parameters. After receiving the new set of broadcast parameters, the receiver uses the new set of broadcast parameters for receiving broadcast services.

Abstract: A method and apparatus for confirming the identity of a mobile station in a communication network. A mobile station transmits a security value to obtain access to the network. The system authenticates the mobile station prior to granting it access to the network. The system performs an additional procedure before granting access to the system if the security value sent by the mobile station matches a previously transmitted security value. Using this invention, the system prevents attempts of replay attacks by intruders.

Abstract: This disclosure describes a key update scheme for use in a mobile IP network. The update scheme may be implemented to facilitate key updates between a mobile device and a server computer that authenticates the mobile device. The techniques described herein can facilitate key updates in a manner that accounts for potential message loss during the update routine, mobile device failure during the update routine, or other problems typically encountered in a mobile network settings. In this manner, the techniques can provide a robust scheme for key updates and may improve network security.

Abstract: A cryptosync design comprising (1) a channel identifier indicative of a particular channel via which a data packet is sent, (2) an extended time stamp indicative of a time value associated with the data packet, and (3) a counter indicative of a packet count associated with the data packet. The lengths of the extended time stamp and counter fields and the time unit for the extended time stamp are parameters that may be configured for each channel. At the sender, the extended time stamp for the cryptosync may be obtained from the System Time maintained by the sender. The counter value for the cryptosync may be provided by a counter that is maintained for the channel by the sender. The sender may include a time stamp and/or the counter value, if they are needed to derive the cryptosync at the receiver, in a header of the data packet.

Abstract: For reestablishing crypto-sync synchronization between a mobile station and a base station in a communication system (100), after establishing an initial crypto-sync synchronization through a registration and acceptance order process (701), the base station may detect loss of the initial crypto-sync synchronization. As a result, the mobile station may receive a base station reject order message (704). In response, the mobile station transmits a security mode request message (705) to the base station. The security mode request message (705) includes a full form of crypto-sync data for reestablishing crypto-sync synchronization between the mobile station and the base station without going through another round of the registration and acceptance order process (701).

Abstract: An apparatus and method for authentication having a processor and at least one activator coupled to the processor is claimed. A signature generator is coupled to the processor and capable of generating a secure identifier. An emitter coupled to the signal generator capable of emitting the secure identifier. A receiver receives the emitted secure identifier and verifies that the secure identifier was appropriately transmitted. The public key corresponding to the key identifier transmitted is accessed to determine the validity of the secure identifier using the accessed key and that the time indicated in the received secure identifier is verified to be within acceptable time tolerances.

Abstract: In a disclosed embodiment, a visitor location register first initializes an assignment table to store N entries. Next, the visitor location register waits until a TMSI assignment is needed. Then, a counter is maintained in memory and is incremented. The value of the counter is then hashed to produce an assignment table index. Beginning at the assignment table index, the assignment table is searched for an available entry. The counter is then encrypted to produce a TMSI. The IMSI corresponding to the TMSI assignment is then stored in the assignment table.

Abstract: A system and method for encrypting all channels of a wireless spread spectrum communication at the chip level. The PN sequence is encrypted with one or more encryption sequences and then used to spread the signal.

Abstract: Techniques for efficient storage and retrieval of Preferred Roaming Lists are disclosed. In one aspect, PRL entries are stored in two tables. One table contains records that are common to two or more PRL entries. Another table stores any information that is unique to a PRL entry, as well as an indicator of which common record is associated with it. The common record is concatenated with the unique information to generate the uncompressed PRL entry. Various other aspects of the invention are also presented. These aspects have the benefit of reducing the memory requirements for storing a PRL. In addition, time required to download the compressed PRL is reduced.

Abstract: In a communication system (100), a method and apparatus provides for message integrity regardless of the operating version of an authentication center (198) or an interface (197) between the authentication center (198) and a mobile switching center (199). The method and apparatus include generating a cellular message encryption algorithm (CMEA) key, and generating a CMEA-key-derived integrity key (CIK) based on the CMEA key for message integrity between a mobile station and a base station. The mobile station transmits a registration message to the base station, and determines an operating version of the authentication center (198) in communication with the base station based on whether the mobile station receives a registration accepted order or some elements of an authentication vector from the base station. The CIK is generated based on the CMEA key, if the mobile station receives a valid registration accepted order from the base station.

Abstract: Method and apparatus for secure transmissions. Each user is provided a registration key. A long-time updated broadcast key is encrypted using the registration key and provided periodically to a user. A short-time updated key is encrypted using the broadcast key and provided periodically to a user. Broadcasts are then encrypted using the short-time key, wherein the user decrypts the broadcast message using the short-time key. One embodiment provides link layer content encryption. Another embodiment provides end-to-end encryption.