Estimating the Circuit De-obfuscation Runtime based on Graph Deep Learning
Zhiqian Chen1,a, Gaurav Kolhe2,c, Setareh Rafatirad4,e, Chang-Tien Lu1,b, Sai Manoj P D3, Houman Homayoun2,d and Liang Zhao4,f
1Department of Computer Science, Virginia Tech, Blacksburg, VA, USA
aczq@vt.edu
bctlu@vt.edu
2Department of Electrical and Computer Engineering, University of California, Davis, CA, USA
cgskolhe@ucdavis.edu
dhhomayoun@ucdavis.edu
3Department of Electrical and Computer Engineering, George Mason University, VA, USA
spudukot@gmu.edu
4Department of Information Science and Technology, George Mason University, VA, USA
esrafatir@gmu.edu
flzhao9@gmu.edu
ABSTRACT
Circuit obfuscation has been proposed to protect digital integrated circuits (ICs) from different security threats such as reverse engineering by introducing ambiguity in the circuit, i.e., the addition of the logic gates whose functionality cannot be determined easily by the attacker. In order to conquer such defenses, techniques such as Boolean satisfiability-checking (SAT)-based attacks were introduced. SAT-attack can potentially decrypt the obfuscated circuits. However, the deobfuscation runtime could have a large span ranging from few milliseconds to a few years or more, depending on the number and location of obfuscated gates, the topology of the obfuscated circuit and obfuscation technique used. To ensure the security of the deployed obfuscation mechanism, it is essential to accurately pre-estimate the deobfuscation time. Thereby one can optimize the deployed defense in order to maximize the deobfuscation runtime. However, estimating the deobfuscation runtime is a challenging task due to 1) the complexity and heterogeneity of the graphstructured circuit, 2) the unknown and sophisticated mechanisms of the attackers for deobfuscation, 3) efficiency and scalability requirement in practice. To address the challenges mentioned above, this work proposes the first machine-learning framework that predicts the deobfuscation runtime based on graph deep learning. Specifically, we design a new model, ICNet with new input and convolution layers to characterize the circuit’s topology, which is then integrated by composite deep fully-connected layers to obtain the deobfuscation runtime. The proposed ICNet is an end-to-end framework that can automatically extract the determinant features required for deobfuscation runtime prediction. Extensive experiments on standard benchmarks demonstrate its effectiveness and efficiency beyond many competitive baselines.
