RANDOM KEY STREAM GENERATING APPARATUS USED IN CIPHER SYSTEM AND METHOD

摘要

PURPOSE: A random key stream generating apparatus used in cipher system and method is provided to generate a random key stream, used in a cipher system or a spread spectrum communication system, in a high speed. CONSTITUTION: A parallel shifting linear feedback shift register(PS-LFSR)(110) consists of n store stages for storing n-bit binary data and is divided into k sub-store parts. The sub-store parts store m-bit parallel binary data from previous sub-store parts at the same time and output the stored m-bit parallel binary data according to a system clock. A buffer(120) consists of m store stages so as to simultaneously store and output m-bit parallel binary data from the last sub-store part of the PS-LFSR. M feedback connections(130) receive outputs of the sub-store parts and the buffer corresponding to predetermined original polynomials, perform calculations according to the original polynomials, and output calculation results as respective bits of a ky stream.