Paper 2021/1363
On Entropy and Bit Patterns of Ring Oscillator Jitter
Markku-Juhani O. Saarinen
Abstract
Thermal jitter (phase noise) from a free-running ring oscillator is a common, easily implementable physical randomness source in True Random Number Generators (TRNGs). We show how to evaluate entropy, autocorrelation, and bit pattern distributions of ring oscillator noise sources, even with low jitter levels or some bias. Entropy justification is required in NIST 800-90B and AIS-31 testing and for applications such as the RISC-V entropy source extension. Our numerical evaluation algorithms outperform Monte Carlo simulations in speed and accuracy. We also propose a new lower bound estimation formula for the entropy of ring oscillator sources which applies more generally than previous ones.
Note: There is supplementary code available at: https://github.com/mjosaarinen/bitpat
Metadata
- Available format(s)
-
PDF
- Category
- Implementation
- Publication info
- Published elsewhere. Minor revision. IEEE AsianHOST 2021
- Keywords
- Ring OscillatorEntropy SourceRandom NumbersStochastic ModelAIS-31NIST SP 800-90B
- Contact author(s)
- mjos @ mjos fi
- History
- 2021-11-04: last of 5 revisions
- 2021-10-12: received
- See all versions
- Short URL
- https://ia.cr/2021/1363
- License
-
CC BY
BibTeX
@misc{cryptoeprint:2021/1363,
author = {Markku-Juhani O. Saarinen},
title = {On Entropy and Bit Patterns of Ring Oscillator Jitter},
howpublished = {Cryptology {ePrint} Archive, Paper 2021/1363},
year = {2021},
url = {https://eprint.iacr.org/2021/1363}
}
