Exploiting Weak PUFs from Data Converter Non-Linearity - E.g. A multibit CT ∆Σ Modulator

Thumbnail Image

Files

AH_TCAS1.pdf (490.91 KB)

Date

2019-08-14

Authors

Journal Title

Journal ISSN

Volume Title

Publication Type

Wissenschaftlicher Artikel

DOI

http://dx.doi.org/10.18725/OPARU-17955

Published in

IEEE Transactions on Circuits and Systems I: Regular Papers, 2016

Abstract

This paper presents a novel approach of deriving Physical Unclonable Functions (PUF) from correction circuits measuring and digitizing non-linearities of data converters. The often digitally available correction data can then be used to generate a fingerprint of the chip. The general concept is presented and then specifically evaluated on an existing Delta-Sigma (∆Σ) modulator whose outermost feedback DAC mismatches are greatly influencing the overall performance and thus need correction. The applied mixed-signal correction scheme reveals the intrinsic mismatches which are firstly used to linearize the ∆Σ modulator, but which can also be further analyzed. The intra-Hamming distance is initially determined to values less than 6% at nominal conditions and could be further reduced to less than 2% by applying different encodings. Regarding the distinctness of devices, the inter-Hamming distance is highly stable under all circumstances with a value very close to 50%. Though the influence of varying environmental conditions on the stability of repeated PUF readouts is negligible, inevitable deviations in the correction coefficients increase the intra-Hamming distance with respect to nominal conditions. As a result, 80 highly stable identification bits are obtained from the exemplarily used ∆Σ modulator.

Description

Faculties

Fakultät für Ingenieurwissenschaften, Informatik und Psychologie

Institutions

Institut für Mikroelektronik

Citation

DFG Project uulm

Keywords

Physical Unclonable Function, DAC linearization, delta sigma modulation, Sigma-Delta-Wandler, Digital-Analog-Umsetzer, Systems engineering, Signal processing, Modulators (Electronics), Digital-to-analog converters, DDC 530 / Physics, DDC 620 / Engineering & allied operations