Adjustable Ring Oscillator RNG for Faster Chaotic Randomness

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Solution Overview

Problem

Existing random number generators using ring oscillators and bistables suffer from low speed and randomness due to slow-moving phase random walk, and analog chaotic circuits are difficult to implement in digital programmable circuits.

Innovation Solution

A random number generator design incorporating adjustable speed ring oscillators and bistables, where the output of at least one bistable is connected to a control input of the adjustable speed ring oscillator, allowing for chaotic behavior and orthogonal data streams, enabling phase correction and random disturbance in the feedback loop.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If ring oscillators with bistables are used for random number generation, then truly random numbers can be generated, but the speed is low due to slow phase random walk

Engineering Contradiction:

Improverandomness qualityVSAvoidgeneration speed

Core Design Contradiction:

ReliabilityVSProductivity

Solution Approach 1:

The patent implements adjustable speed ring oscillators where the delay time can be dynamically modified. This allows the system to adapt the oscillation frequency and phase random walk speed, resolving the contradiction between maintaining high randomness quality and achieving faster generation speeds through dynamic parameter adjustment.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The patent changes the delay parameter of the ring oscillator to optimize performance. By adjusting the delay time in the delay line, the system can control the phase random walk speed, thereby improving the generation speed while preserving the randomness quality through parameter optimization.

Inventive Principle:

Principle #35Parameter changes

2Reliability

If analog chaotic circuits are used for random number generation, then continuous variables and chaotic behavior are obtained, but they cannot be implemented in digital programmable circuits

Engineering Contradiction:

Improvechaotic behavior qualityVSAvoiddigital implementation difficulty

Core Design Contradiction:

ReliabilityVSEase of manufacture

Solution Approach 1:

The patent replaces the mechanical/analog chaotic circuit with a digital implementation using ring oscillators and delay lines in a programmable logic device. The digital circuit replicates the chaotic behavior through feedback loops and delay elements, substituting analog components with digital equivalents that can be manufactured using standard digital technology processes.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent segments the chaotic system into discrete digital components: ring oscillators, delay lines, and feedback logic. This segmentation allows the chaotic behavior to be implemented using digital logic elements that can be programmed and manufactured digitally, while maintaining the essential chaotic dynamics through the segmented architecture.

Inventive Principle:

Principle #1Segmentation

3Productivity

If phase detector is used instead of metastability circuit, then speed improves, but randomness quality decreases due to slow phase random walk

Engineering Contradiction:

Improveoperation speedVSAvoidrandomness quality

Core Design Contradiction:

ProductivityVSReliability

Solution Approach 1:

The patent introduces an intermediary element - the adjustable delay line - between the phase detection mechanism and the feedback loop. This intermediary allows fine-tuning of the phase relationship and random walk characteristics, enabling the system to achieve both high speed operation and high randomness quality by mediating the interaction between speed and randomness.

Inventive Principle:

Principle #24Intermediary (Mediator)

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

This design achieves simultaneous generation of multiple independent random sequences with improved chaotic behavior and randomness, suitable for digital implementation while retaining analog properties, enhancing the speed and randomness of generated numbers.

Implementation Method 1

low speed resulting from rare occurrences of events that are able to initiate a metastable work of the metastability circuit, which results from slow-moving random walk in phase

Methodology Applied

Scientific EffectRandom walk in phase: Brownian Motion

Implementation Method 2

at least one of the ring oscillators is an adjustable speed ring oscillator... allowing for chaotic behavior and orthogonal data streams

Methodology Applied

Scientific EffectDelay time adjustment:

Implementation Method 3

outputs of the ring oscillators are connected to inputs of the metastability circuit... the output of at least one of the bistables is connected to a control input of the adjustable speed ring oscillator

Methodology Applied

Scientific EffectPhase detection:

Data Source

PatentUS11366640B2Random number generator with a bistable and ring oscillators

Publication Date: 2022.06.21 POLITECHNIKA WARSZAWSKA

AI summary

Random number generator (GL) comprising adjustable speed ring oscillators (GPRS, GPRS′), which have outputs (o-GPRS, o-GPRS′) connected to inputs (i1-UM, i2-UM) of a metastability circuit (UM) and inputs (i1-DF, i2-DF) of a phase detector (DF), which outputs (o-UM, o-DF) are connected to inputs (r-US′, i-US′) of a control circuit (US′), having output (o-US′) connected to control inputs (s-GPRS, s-GPRS′) of the adjustable speed ring oscillators (GPRS, GPRS′). The outputs (o-UM, o-DF) of the metastability circuit (UM) and the phase detector (DF) are being outputs (o-GL, o2-GL) of the random number generator (GL).