Obfuscating the Interconnects: Low-Cost and Resilient Full-Chip Layout
Camouflaging
release_ohfqked5snbk3ejjm6pdq5geua
by
Satwik Patnaik, Mohammed Ashraf, Ozgur Sinanoglu, Johann Knechtel
2020
Abstract
Layout camouflaging can protect the intellectual property of modern circuits.
Most prior art, however, incurs excessive layout overheads and necessitates
customization of active-device manufacturing processes, i.e., the
front-end-of-line (FEOL). As a result, camouflaging has typically been applied
selectively, which can ultimately undermine its resilience. Here, we propose a
low-cost and generic scheme---full-chip camouflaging can be finally realized
without reservations. Our scheme is based on obfuscating the interconnects,
i.e., the back-end-of-line (BEOL), through design-time handling for real and
dummy wires and vias. To that end, we implement custom, BEOL-centric
obfuscation cells, and develop a CAD flow using industrial tools. Our scheme
can be applied to any design and technology node without FEOL-level
modifications. Considering its BEOL-centric nature, we advocate applying our
scheme in conjunction with split manufacturing, to furthermore protect against
untrusted fabs. We evaluate our scheme for various designs at the physical,
DRC-clean layout level. Our scheme incurs a significantly lower cost than most
of the prior art. Notably, for fully camouflaged layouts, we observe average
power, performance, and area overheads of 24.96%, 19.06%, and 32.55%,
respectively. We conduct a thorough security study addressing the threats
(attacks) related to untrustworthy FEOL fabs (proximity attacks) and malicious
end-users (SAT-based attacks). An empirical key finding is that only
large-scale camouflaging schemes like ours are practically secure against
powerful SAT-based attacks. Another key finding is that our scheme hinders both
placement- and routing-centric proximity attacks; correct connections are
reduced by 7.47X, and complexity is increased by 24.15X, respectively, for such
attacks.
In text/plain
format
Archived Files and Locations
application/pdf 5.4 MB
file_vldafoct2vdfpekqgjvxp674mq
|
arxiv.org (repository) web.archive.org (webarchive) |
2003.10830v1
access all versions, variants, and formats of this works (eg, pre-prints)