Active test and alteration of sample times for a ring based random number generator

Patent metadata

Field	Value
Publication number	US-9785409-B1
Application number	US-201414186668-A
Country	US
Kind code	B1
Filing date	Feb 21, 2014
Priority date	Sep 18, 2007
Publication date	Oct 10, 2017
Grant date	Oct 10, 2017

Abstract

An apparatus can include at least one test circuit configured to determine if bits sampled at a sample frequency from at least one bit generator are random, and a circuit configured to adjust the sample frequency if the at least one test circuit determines that the sampled bits are not random. The apparatus can be a random number generator. A method may include sampling bits at a first sample frequency, and sampling bits at a second sample frequency if the sampled bits associated with the first sample frequency are not random.

First claim

What is claimed is:

1. An apparatus comprising:
first circuitry to determine if bits sampled at a sample frequency are random; and
second circuitry to adjust the sample frequency if the first circuitry determines that the sampled bits are not random.

2. The apparatus of claim 1 wherein the apparatus is a random number generator.

3. The apparatus of claim 1 further comprising at least one generator to generate the sampled bits.

4. The apparatus of claim 3 wherein the at least one generator includes one of a drifting oscillator and a ring oscillator.

5. The apparatus of claim 1 wherein the first circuitry includes at least one counter.

6. The apparatus of claim 1 further comprising a whitener coupled to receive the sampled bits.

7. The apparatus of claim 1 wherein the sampled bits are output to, and in parallel with, the first circuitry.

8. A method comprising:
sampling bits at a first sample frequency; and
sampling bits at a second sample frequency if the sampled bits associated with the first sample frequency are not random.

9. The method of claim 8 further comprising testing the sampled bits associated with the first sample frequency for randomness.

10. The method of claim 9 wherein the testing includes counting logical states of the sampled bits and generating an error when the counted logical states reaches a predetermined value.

11. The method of claim 8 wherein the bits are produced by ring oscillators.

12. The method of claim 8 further comprising whitening the sampled bits to produce a random number output.

13. The method of claim 12 wherein the whitening uses a hash algorithm on the sampled bits.

14. A random number generator comprising:
at least one bit generator;
at least one test circuit configured to determine if bits sampled at a sample frequency from at least one bit generator are random; and
a circuit configured to adjust the sample frequency if the at least one test circuit determines that the sampled bits are not random.

15. The random number generator of claim 14 further comprising:
additional bit generators; and
additional test circuits, each bit generator is associated with a test circuit.

16. The random number generator of claim 14 , wherein the sample frequency can be adjusted based on a number of bit generators that are producing constant values.

17. The random number generator of claim 14 further comprising a whitener coupled to receive the sampled bits.

18. The random number generator of claim 17 wherein the whitener outputs a true random number when at least four of the bit generators are generating random sampled bits.

19. The random number generator of claim 15 wherein the each bit generator operates at a different frequency.

20. The random number generator of claim 14 wherein the at least one bit generator includes one of a drifting oscillator and a ring oscillator.

Assignees

• Seagate Technology Llc

Inventors

• Matthews Jr Donald Preston
• Hars Laszlo

Classifications

• G06F7/588 Primary

  Random number generators, i.e. based on natural stochastic processes · CPC title

• G06F7/58 Primary

  Random or pseudo-random number generators · CPC title