Ring oscillator based true random number generator and a method for generating a random number
AssigneeNXP B.V.
InventorBjörn Fay
Life of this patent
Estimating the term…
Abstract
A true random number generator circuit includes a ring oscillator and a plurality of sampling circuits. The ring oscillator includes a plurality of series-connected stages coupled together in a ring. An output of a last stage of the ring oscillator is coupled to an input of a first stage of the ring oscillator. A sampling circuit of the plurality of sampling circuits has an input coupled to a node located between two adjacent stages of the plurality of series-connected stages. Every node of the ring oscillator is coupled to a corresponding sampling circuit of the plurality of sampling circuits. In another embodiment, a method for generating a random number is provided.
Claims17
A random number generator circuit comprising:
- a first ring oscillator having a plurality of series-connected stages coupled together in a ring, wherein an output of a last stage of the first ring oscillator is coupled to an input of a first stage of the first ring oscillator;
- a plurality of sampling circuits, a sampling circuit of the plurality of sampling circuits having an input coupled to a node located between two adjacent stages of the plurality of series-connected stages, wherein every node of the first ring oscillator is coupled to a corresponding sampling circuit of the plurality of sampling circuits;
- a second ring oscillator having an output;
- and
- a counter having an input coupled to the output of the second ring oscillator, and an output, wherein the second ring oscillator and the counter are for providing a sampling pulse for controlling sampling of the first ring oscillator using the plurality of sampling circuits.
A true random number generator circuit comprising:
- a first ring oscillator having a plurality of series-connected stages coupled together in a ring, wherein an output of a last stage of the first ring oscillator is coupled to an input of a first stage of the first ring oscillator;
- a plurality of sampling circuits, a sampling circuit of the plurality of sampling circuits having an input coupled to a node located between two adjacent stages of the plurality of series-connected stages, wherein every node of the first ring oscillator is coupled to a corresponding sampling circuit of the plurality of sampling circuits;
- a synchronization circuit coupled to an output of each of the plurality of sampling circuits;
- a second ring oscillator having an output;
- and
- a counter having an input coupled to the output of the second ring oscillator, and an output, wherein the second ring oscillator and the counter for providing a sampling pulse for controlling sampling of the first ring oscillator using the plurality of sampling circuits.
A method for generating a random number comprising:
- providing a first ring oscillator having a plurality of series-connected stages coupled together in a ring, wherein an output of a last stage of the first ring oscillator is coupled to an input of a first stage of the ring oscillator;
- sampling, using a plurality of sampling circuits, output signals from the ring oscillator, wherein a sampling circuit of the plurality of sampling circuits having an input coupled to a node located between two adjacent stages of the plurality of series-connected stages, wherein every node of the first ring oscillator is coupled to a corresponding sampling circuit of the plurality of sampling circuits;
- providing a second ring oscillator having an output;
- and
- providing a counter having an input coupled to the output of the second ring oscillator, and an output, wherein the second ring oscillator and the counter for providing a sampling pulse for controlling sampling of the first ring oscillator using the plurality of sampling circuits.
Dependencies are inferred from the claim text.