In a wireless communication system, a method and system for implementing
the GEA3 encryption algorithm for GPRS compliant handsets are provided.
An intermediate value may be generated based on initialized input
variables, a cipher key and a key modifier. A first processing block of
output bits may be generated by a keystream generator from the
intermediate value, the cipher key, and an indication of the processing
block of output bits being processed. Additional processing blocks of
output bits may also be generated by the keystream generator based on an
immediately previous processing block of output bits, the intermediate
value, the cipher key, and an indication of the processing block of
output bits being processed. A restart signal may indicate that
subsequent processing blocks of output bits may be generated by the
keystream generator by utilizing the same cipher key and the generated
intermediate value.