Intrinsically Reliable and Lightweight Physical Obfuscated Keys

TL;DR

This paper introduces two new physical obfuscated key designs that are inherently reliable and lightweight, using XOR circuitry and material variability, eliminating the need for additional error correction or privacy amplification.

Contribution

The paper presents intrinsically reliable POK designs leveraging lithographic and phase change memory variability, simplifying the security architecture.

Findings

Demonstrated through experiments and simulations

Achieve reliability without additional error correction

Use XOR circuitry for privacy amplification

Abstract

Physical Obfuscated Keys (POKs) allow tamper-resistant storage of random keys based on physical disorder. The output bits of current POK designs need to be first corrected due to measurement noise and next de-correlated since the original output bits may not be i.i.d. (independent and identically distributed) and also public helper information for error correction necessarily correlates the corrected output bits.For this reason, current designs include an interface for error correction and/or output reinforcement, and privacy amplification for compressing the corrected output to a uniform random bit string. We propose two intrinsically reliable POK designs with only XOR circuitry for privacy amplification (without need for reliability enhancement) by exploiting variability of lithographic process and variability of granularity in phase change memory (PCM) materials. The two designs are demonstrated through experiments and simulations.