Abstract: An authentication system is disclosed. The authentication system includes a content provider configured to distribute encrypted content, wherein the encrypted content is generated using a content key, and a client having a symmetric key and configured to store the encrypted content received from the content provider and issue a request to the content provider, wherein the request includes a cryptographic function configured to have the symmetric key and the encrypted content as input, wherein the content provider is further configured to verify the client via the request to ensure that the client has received the encrypted content.

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: Access to a variable rate multiple access system is controlled based upon a current loading. The current loading level is used to determine a transmission rate set point. The transmission rate set point may include a maximum transmission rate and a transmission probability. The transmission rate set point is passed to the remote unit which may access the system. A remote unit with data to send determines a desired transmission data rate. If the desire transmission data rate is equal to or greater than the maximum transmission data rate, the remote unit transmits at the maximum transmission data rate with a probability equal to the transmission probability.

Abstract: A method and apparatus for transmitting and receiving data provide for efficient use communication resources by encoding data in accordance with a first code to produce a block of data, determining transmission data rate of a time frame, selecting a portion of the block of data based on the determined transmission data rate, adding a location identifier data to the portion of data to produce a payload data, wherein the location identifier identifies a location of the portion of data within the block of data, and encoding the payload data in accordance with a second code to produce a packet of data for transmission over the time frame. A transmitter transmits the packet of data over the time frame at the determined data rate. A receiver receives the packet of data over the time frame, and processes the received data accordingly to reproduce the block of data.