This paper presents a method to implement digital chaotic systems with finite precision via composing LFSR sequences. The period and correlation are studied under different order of LFSR. An application of information security is an example for this approach.
It is important to generate random number in cryptography. In this paper, we design Pseu-do-random Bit Generator (PRBG), based on Rijndael with a block length of 256 and a cipher key length of 256 by applying the OFB mode. The random nature and the security have been analyzed. The PRBG is also easy to be realized in application.