Title
Reversing stealthy dopant-level circuits
Abstract
A successful detection of the stealthy dopant-level circuit (trojan), proposed by Becker et al. at CHES 2013 (LNCS 8086:197–214, 2013), is reported. Contrary to an assumption made by Becker et al. dopant types in active region are visible with either scanning electron microscopy (SEM) or focused ion beam (FIB) imaging. The successful measurement is explained by a technique called the passive voltage contrast (Rosenkranz J Mater Sci Mater Electron 22(10):1523–1535, 2011) which is used to analyze failures in large-scale integration (LSI). The experiments are conducted by measuring a dedicated chip. The chip uses the diffusion programmable device (Shiozaki et al. Diffusion programmable device: a device to prevent reverse engineering, IACR Cryptology ePrint Archive 2014/109 2014): an anti-reverse engineering technique by the same principle as the stealthy dopant-level trojan. The chip is delayered down to the contact layer, and images are taken with (1) an optical microscope, (2) SEM, and (3) FIB. As a result, the four possible dopant–well combinations, namely (i) p+/n-well, (ii) p+/p-well, (iii) n+/n-well and (iv) n+/p-well are distinguishable in the SEM images. Partial but sufficient detection is also achieved with FIB. Although the stealthy dopant-level circuits are visible, they potentially make a detection harder. That is because the contact layer should be measured. We show that imaging the contact layer is at most 16 times more expensive than that of a metal layer in terms of the number of images.
Year
DOI
Venue
2015
10.1007/s13389-015-0102-5
J. Cryptographic Engineering
Keywords
Field
DocType
Stealthy dopant-level trojan, Chip reverse engineering, LSI failure analysis, Passive voltage contrast
Optical microscope,Dopant,Computer security,Scanning electron microscope,Chip,Focused ion beam,Trojan,Electronic circuit,Materials science,Optoelectronics,Electron
Journal
Volume
Issue
ISSN
5
2
2190-8516
Citations 
PageRank 
References 
7
0.52
4
Authors
7
Name
Order
Citations
PageRank
Takeshi Sugawara1146.77
Daisuke Suzuki230621.80
Ryoichi Fujii370.52
Shigeaki Tawa470.52
Ryohei Hori571.54
Mitsuru Shiozaki6157.44
Takeshi Fujino7168.98