True Random Number Generator Using Parasitic Capacitors

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Solution Overview

Problem

Current true random number generators for mobile and embedded devices rely on pseudo-random number generators for security, which are inadequate, and true random number generation methods require additional hardware, increasing cost and power consumption, making them impractical for cost-sensitive applications like IoT devices.

Innovation Solution

A true random number generator utilizing parasitic capacitors on chip pins and PCB wires, which vary with environmental conditions and noise, to generate truly random numbers without additional hardware, using a sampling circuit and random number generating circuit to sample and process voltage variations.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a true random number generator uses additional peripheral hardware circuits to generate true random numbers, then the reliability and security are improved, but the hardware cost, circuit area, and power consumption increase

Engineering Contradiction:

Improvetrue random number generation reliabilityVSAvoidhardware circuit complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The invention uses the device's own existing capacitors (parasitic capacitors) to generate random numbers, eliminating the need for separate dedicated hardware circuits. The capacitors that are already present in the device serve dual purposes: their original function and now also as the random number generation source, achieving self-service and reducing hardware complexity

Inventive Principle:

Principle #25Self-service

Solution Approach 2:

The existing capacitors in the device are made to serve multiple functions: their original function plus the additional function of generating random numbers. This multi-functionality approach eliminates the need for dedicated TRNG hardware, reducing overall device complexity while maintaining true random number generation capability

Inventive Principle:

Principle #6Universality (Multi-functionality)

2Reliability

If a true random number generator uses additional peripheral hardware circuits, then the security is improved, but the power consumption increases

Engineering Contradiction:

ImprovesecurityVSAvoidpower consumption

Core Design Contradiction:

ReliabilityVSUse of energy by moving object

Solution Approach 1:

The device utilizes its existing capacitors for random number generation, avoiding the need for separate powered hardware circuits. This self-service approach reduces the additional power consumption that would otherwise be required to operate dedicated TRNG hardware while maintaining security through true random number generation

Inventive Principle:

Principle #25Self-service

3Ease of manufacture

If a true random number generator uses parasitic capacitors on chip pins and PCB wires, then the hardware cost is reduced, but the measurement precision of random number generation may be affected

Engineering Contradiction:

Improvehardware costVSAvoidrandom number generation precision

Core Design Contradiction:

Ease of manufactureVSMeasurement precision

Solution Approach 1:

The invention converts the previously harmful or negligible parasitic capacitors into a beneficial resource for random number generation. These parasitic capacitors, which were formerly considered unwanted electrical effects, are now utilized as the core component for generating true random numbers, reducing hardware cost while achieving the desired measurement precision through proper sampling and processing

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

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 approach allows for reliable and efficient true random number generation with reduced hardware costs and power consumption, making it suitable for cost-sensitive applications like IoT devices without the need for additional peripheral circuits.

Implementation Method 1

utilizing parasitic capacitors on chip pins and PCB wires, which vary with environmental conditions and noise

Methodology Applied

Scientific EffectCapacitance: Capacitance

Implementation Method 2

The sampling circuit is configured to sample N voltage(s) of N capacitor(s) according to a clock signal and thereby generate N sample value(s)

Methodology Applied

Scientific EffectParasitic Capacitance: Parasitic Capacitance

Data Source

PatentUS11416219B2True random number generator and method for generating true random number

Publication Date: 2022.08.16 REALTEK SEMICON CORP

AI summary

Disclosed is a true random number generator and a method for generating a true random number. The true random number generator includes a sampling circuit and a random number generating circuit. The sampling circuit is configured to sample N voltage(s) of N capacitors according to a clock signal and thereby generate N sample value(s), in which the N is a positive integer. The random number generating circuit is configured to generate a random number according to at least a part of the N sample value(s).