Paper 2026/2696
Ratio-Based Ring Oscillator PUF Statistical Model
Abstract
A ratio-based ring oscillator physical unclonable function (ROPUF) provides high reliability and is capable of extracting multiple bits from a single ring oscillator pair. However, the derivation of the response bits from such PUFs and the assessment of their randomness have relied only on empirical statistical tests. This paper introduces a novel, mathematically derived closed-form statistical model that characterizes the counter value distribution of the ratio-based ROPUF and formally describes the behavior of this PUF design. We empirically validate the model's assumptions using a large-scale real-world ring oscillator measurement dataset of 218 Xilinx Artix-7 FPGAs. We demonstrate that this statistical framework enables theoretical quantification of response entropy of the ratio-based ROPUF. Furthermore, the model unlocks the use of advanced bit derivation methods, such as Equiprobable Quantization and Two-Metric Helper Data schemes. These were previously inapplicable to this PUF architecture, and we empirically show on the real-world dataset that they achieve better combinations of PUF reliability, randomness, and bit yield than the original counter-based derivation.
Note: The DOI to the published manuscript at CASCADE 2027 will be updated when available.
Metadata
- Available format(s)
-
PDF
- Category
- Implementation
- Publication info
- Published elsewhere. Minor revision. CASCADE 2027, LNCS, Springer
- Keywords
- physical unclonable functionring oscillatorFPGAstatistical modelbit derivation
- Contact author(s)
- staniond @ fit cvut cz
- History
- 2026-11-04: approved
- 2026-10-30: received
- See all versions
- Short URL
- https://ia.cr/2026/2696
- License
-
CC BY
BibTeX
@misc{cryptoeprint:2026/2696,
author = {Ondřej Staníček and Jiří Buček and Róbert Lórencz},
title = {Ratio-Based Ring Oscillator {PUF} Statistical Model},
howpublished = {Cryptology {ePrint} Archive, Paper 2026/2696},
year = {2026},
url = {https://eprint.iacr.org/2026/2696}
}
