Patent ID: 7647366
Filing Date: 2010-01-12
Classification: G06F

Abstract:
1. An apparatus for generating a random number, comprising: a noise source configured to generate a noise signal; an analog-to-digital converter, coupled to the noise source, and configured to sample the noise signal to obtain a digital noise signal sample; hardware provider logic configured to generate at least three noise signal threshold values, the at least three noise signal threshold values being selected such that a first probability of the digital noise signal sample being between the first and second noise signal threshold values, and a second probability of the digital noise signal sample being between the second and third noise signal threshold values are different from each other by less than a predetermined differential value or are identical; and hardware output stage, coupled to the analog-to-digital converter and to the provider logic, and configured to generate the random number having at least two digits which depend on the digital noise signal sample, wherein, if the digital noise signal sample is between the first and second noise signal threshold values, a first digit of the random number obtains a first state, and a second digit of the random number, representing a range between the second noise signal threshold value and the third noise signal threshold value, obtains a second state which differs from the first state, wherein the noise signal has a probability-density function which has been predetermined, wherein the probability of a noise signal sample being smaller than or equaling a noise signal threshold value is given by the following equation: wherein p(y) is the probability-density function of the noise signal, wherein y is a noise signal threshold value, and wherein the hardware provider logic is configured to specify the noise signal threshold values in accordance with the following equation: wherein i is a control variable, wherein F