APPARATUS AND METHOD FOR INTEGRATING 8-ROUND ENCRYPTION ALGORITHM IN ONE SINGLE-ROUND ENCRYPTION BLOCK IN MOBILE COMMUNICATION SYSTEMS

摘要

PURPOSE: An apparatus and a method for single-round encryption in a mobile communication system are provided to reduce the number of elements used for encryption by integrating 8-round encryption algorithm in one single-round encryption block. CONSTITUTION: An encryption apparatus divides 2n-input bit streams to two sub bit streams and outputs a 2n-output bit stream. A first encryption portion receives the first sub bit stream and performs encryption using a first encryption code to output a first encryption bit stream having length n. The first encryption portion alternatively receives the second sub bit stream and performs encryption using the first encryption code to output a third encryption bit stream having length n. A second encryption portion receives the first encryption bit stream and performs encryption using a second or third encryption code to output a fourth encryption bit stream having length n. The second encryption portion alternatively receives the first sub bit stream and performs encryption using the second or third encryption code to output a second encryption bit stream having length n. A plurality of first registers synchronize a calculation delay of the second encryption portion with the second sub bit stream.