METHOD FOR POST-PROCESSING AN OUTPUT OF A RANDOM SOURCE OF A RANDOM GENERATOR

• US 20150019602A1
• Filed: 07/07/2014
• Published: 01/15/2015
• Est. Priority Date: 07/09/2013
• Status: Active Grant

• Current Assignee: Robert Bosch GmbH
• Original Assignee: Robert Bosch GmbH
• Inventors: LEWIS, Matthew, BOEHL, Eberhard
• Granted Patent: US 9,720,650 B2
• Time in Patent Office: Days
• US Class Current: 708/203
• CPC Class Codes: G06F 7/588 Random number generators, i.e. based on natural stochastic processes
• CPC Class Codes: H03M 5/145 Conversion to or from block codes or representations thereof
• CPC Class Codes: H03M 7/14 Conversion to or from non-weighted codes
• CPC Class Codes: H03M 7/30 Compression speech analysis-synthesis for redundancy reduction G10L19/00; for image communication H04N; Expansion; Suppression of unnecessary data, e.g. redundancy reduction
• CPC Class Codes: H03M 7/6011 Encoder aspects

Abstract

A method and as assemblage for post-processing an output of a random source of a random generator are presented. In the method, an output signal of the random source is compressed, thereby yielding a sequence of compressed signal values that are checked in terms of their distribution.

Claims

1. A method for post-processing an output of a random source of a random generator, the random source outputting a digital output signal having a bit width of at least one bit, comprising:

compressing the output signal; and

performing a blockwise linear logical combination of n successive bits of the output signal in a context of the compression, wherein n is a compression factor, with a result that a compressed output signal is generated that encompasses a sequence of compressed signal values, the sequence of compressed signal values being checked by a distribution test in terms of a distribution of the sequence.

2. The method as recited in claim 1, in which the distribution test is carried out by taking a difference between values of separate counters.

3. The method as recited in claim 1, wherein the compression factor n is influenced as a function of the result of the distribution test.

4. The method as recited in claim 1, wherein the random source includes a ring oscillator that encompasses a ring-shaped interconnection of an odd number of inverting elements, the ring oscillator being sampled with a sampling clock at at least one sampling point.

5. The method as recited in claim 4, wherein a frequency of the sampling clock is influenced as a function of the result of the distribution test.

6. The method as recited in claim 4, wherein a frequency of the ring oscillator is influenced as a function of the result of the distribution test.

7. The method as recited in claim 6, wherein a frequency of the ring oscillator is influenced by selecting a number of inverting elements.

8. The method as recited in claim 6, wherein a frequency of the ring oscillator is influenced by modifying operating conditions.

9. The method as recited in claim 1, wherein the output signal of the random source includes a plurality of bits, and wherein at least two of the bits are combined by way of a linear operation into one bit that is correspondingly compressed by blockwise XORing of n successive bits, yielding a compressed bit sequence, and the compressed bit sequence is tested with regard to its distribution.

10. The method as recited in claim 1, wherein the output signal of the random source includes at least k bits, each of said k bits being equipped with a circuit for processing the output signal, the corresponding compressed k bits constituting an assignment having 2^k possible values, and an occurrence of all the 2^k possible values being counted in separate counters, and a frequency of occurrence of all the assignments are mutually compared.

11. An assemblage for post-processing an output of a random source of a random generator that outputs a digital output signal having a bit width of at least one bit, the assemblage comprising:

a circuit for compressing the output signal, a blockwise linear logical combination of n successive bits of the output signal being performed in a context of the compression, n being a compression factor, with a result that a compressed output signal is generated which encompasses a sequence of compressed signal values; and

a device with which the sequence of compressed signal values is checked in terms of a distribution of the sequence.