Oscillator Pause Sampling for Unbiased Random Number Generation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing random number generators often produce biased or predictable random numbers, lacking true randomness and unpredictability, which compromises security systems' integrity.
Innovation Solution
A random number generator design incorporating an oscillator, signal generator, duty rectifier, and sampler, utilizing oscillation signal pauses and synchronization to generate unbiased random numbers through jitter accumulation and synchronized sampling.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a traditional random number generator uses thermal noise or shot noise to generate random numbers, then the generation speed may be improved, but the randomness quality deteriorates due to bias and predictability
Solution Approach 1:
The patent uses a ring oscillator whose oscillation period dynamically varies due to jitter accumulation from thermal noise, rather than using static noise sampling. This dynamic oscillation period creates unpredictable pause times that enhance randomness quality while maintaining generation speed
Solution Approach 2:
The patent changes the parameter being measured from direct noise voltage (which has bias) to time interval (pause time) between oscillation cycles. This parameter transformation converts biased noise into unbiased random numbers by measuring the temporal characteristics of oscillator pauses
2Productivity
If the oscillator runs continuously to generate random numbers, then the productivity is improved, but the randomness quality worsens due to periodicity and bias
Solution Approach 1:
The patent introduces periodic pause signals that temporarily stop the oscillator at regular intervals. These controlled pauses prevent continuous oscillation periodicity while allowing jitter accumulation during active periods, creating unpredictable pause durations that enhance randomness
Solution Approach 2:
The patent allows jitter to accumulate in the oscillator before triggering a pause and subsequent random number generation. This preliminary jitter accumulation phase ensures that when the oscillator pauses, the accumulated phase uncertainty translates into unpredictable pause times
3Device complexity
If the sampling is performed without synchronization to the oscillation signal, then the device complexity is reduced, but the manufacturing precision worsens due to duty cycle variations and previous value dependencies
Solution Approach 1:
The patent introduces a synchronizer circuit that acts as an intermediary between the oscillator and sampler. This synchronizer aligns the sampling clock with the oscillation signal edges, ensuring that sampling occurs at consistent points in the oscillation cycle and eliminating duty cycle variations
Solution Approach 2:
The synchronizer uses feedback from the oscillation signal itself to generate the sampling clock, ensuring that the sampling timing is always synchronized with the actual oscillation edges rather than using a fixed external clock. This feedback mechanism adapts to jitter variations while maintaining synchronization
Data Source
AI summary
A random number generator, including: an oscillator configured to generate a first oscillation signal; a signal generator configured to generate a first clock signal based on the first oscillation signal and a pause signal, and to generate a second clock signal based on the pause signal; a duty rectifier configured to generate a second oscillation signal based on the first clock signal, wherein a pulse width of the second oscillation signal is greater than a pulse width of the first clock signal; and a sampler configured to sample the second oscillation signal based on the second clock signal