PROCESSOR METHOD TRANSMITTER AND TERMINAL FOR USE IN COMMUNICATIONS

摘要

A processor for producing an encryption keystream to encrypt information to be communicated from a first location to a second location includes a keystream generator operable to generate a keystream; and a divider operable to divide the keystream into blocks including encryption portions and synchronisation portions; wherein each of the blocks is sub-divided into a plurality of equally sized sub-blocks and comprises a plurality of separate encryption portions each in a respective one of the sub-blocks and a single synchronisation portion in one of the sub-blocks. Also described are an encryption processor using the processor and methods using the processor and the encryption processor. A transmitter using the encryption processor and a telecommunications terminal and method using the terminal are also described.