Making Obfuscated PUFs Secure Against Power Side-Channel Based Modeling Attacks
Trevor Kroeger1,a, Wei Cheng2, Sylvain Guilley3,2,a, Jean-Luc Danger2,3,b and Naghmeh Karimi1,b
1CSEE Department University of Maryland Baltimore County Baltimore, MD 21250
aTrevor.Kroegerlastname@umbc.edu
bNaghmeh.Karimi@umbc.edu
2LTCI, Télécom Paris Institut Polytechnique de Paris 91 120 Palaiseau (Paris), France
Wei.Cheng@telecom-paris.fr
3Think Ahead Business Line Secure-IC S.A.S. 35 510 Cesson-Sévigné, France
aSylvain.Guilley@secure-ic.com
bJean-Luc.Danger@secure-ic.com
ABSTRACT
To enhance the security of digital circuits, there is often a desire to dynamically generate, rather than statically store, random values used for identification and authentication purposes. Physically Unclonable Functions (PUFs) provide the means to realize this feature in an efficient and reliable way by utilizing commonly overlooked process variations that unintentionally occur during the manufacturing of integrated circuits (ICs) due to the imperfection of fabrication process. When given a challenge, PUFs produce a unique response. However, PUFs have been found to be vulnerable to modeling attacks where by using a set of collected challenge response pairs (CRPs) and training a machine learning model, the response can be predicted for unseen challenges. To combat this vulnerability, researchers have proposed techniques such as Challenge Obfuscation. However, as shown in this paper, this technique can be compromised via modeling the PUF’s power side-channel. We first show the vulnerability of a state-of-the-art Challenge Obfuscated PUF (CO-PUF) against power analysis attacks by presenting our attack results on the targeted CO-PUF. Then we propose two countermeasures, as well as their hybrid version, that when applied to the CO-PUFs make them resilient against power side-channel based modeling attacks. We also provide some insights on the proper design metrics required to be taken when implementing these mitigations. Our simulation results show the high success of our attack in compromising the original Challenge Obfuscated PUFs (success rate > 98%) as well as the significant improvement on resilience of the obfuscated PUFs against power side-channel based modeling when equipped with our countermeasures.
