Robust Design-for-Security Architecture for Enabling Trust in IC Manufacturing and Test

Due to the prohibitive costs of semiconductor manufacturing, most system-on-chip design companies outsource their production to offshore foundries. As most of these devices are manufactured in environments of limited trust that often lack appropriate oversight, a number of different threats have emerged. These include unauthorized overproduction of the integrated circuits (ICs), sale of out-of-specification/ rejected ICs discarded by manufacturing tests, piracy of intellectual property, and reverse engineering of the designs. Over the years, researchers have proposed different metering and obfuscation techniques to enable trust in outsourced IC manufacturing, where the design is obfuscated by modifying the underlying functionality and only activated by using a secure obfuscation key. However, Boolean satisfiability-based algorithms have been shown to efficiently break key-based obfuscation methods, and thus circumvent the primary objectives of metering and obfuscation. In this paper, we present a novel secure cell design for implementing the design-for-security infrastructure to prevent leaking the key to an adversary under any circumstances. Importantly, our design does not limit the testability of the chip during the normal manufacturing flow in any way, including postsilicon validation and debug. Our proposed design is resistant to various known attacks at the cost of a very little (< 1%) area overhead.