Enhanced random number generator

摘要

In this invention is described a linear feedback shift register that is enhanced with XOR circuits and free running oscillators to maximize the random nature of the sequence of digital bit created at the output of the generator in response to a clock signal. XOR circuits are included in the feedback path of a LFSR to randomize digital signals being fed back from the output to the input. Additional XOR circuits are interposed between stages of the LFSR and each connected to a high frequency oscillator to randomize the digital signals flowing between stages of the LFSR. The frequency of the oscillators are set so as not to be duplicated, and not to be a factor or multiple of another oscillator connected to the enhanced LFSR. The frequency of the oscillators are higher than the frequency of the clock used to step the LFSR. The output of the LFSR is a highly randomized sequence of digital bits that can be used in integrated circuits for such purposes as Smart Cards.