Secure and Lightweight Strong PUF Challenge Obfuscation with Keyed Non-linear FSR

TL;DR

This paper introduces a secure, lightweight challenge obfuscation method for strong PUFs using non-linear feedback shift registers, enhancing resistance to learning and side-channel attacks with minimal cost increase.

Contribution

It presents a novel challenge obfuscation architecture for strong PUFs based on NLFSRs, providing security against learning and power analysis attacks with low overhead.

Findings

Security against learning attacks demonstrated via avalanche criterion and neural networks.

Testchip implementation in 65 nm CMOS shows minimal cost increase.

Obfuscation effectively resists power analysis with clock randomization and masking.

Abstract

We propose a secure and lightweight key based challenge obfuscation for strong PUFs. Our architecture is designed to be resilient against learning attacks. Our obfuscation mechanism uses non-linear feedback shift registers (NLFSRs). Responses are directly provided to the user, without error correction or extra post-processing steps. We also discuss the cost of protecting our architecture against power analysis attacks with clock randomization, and Boolean masking. Security against learning attacks is assessed using avalanche criterion, and deep-neural network attacks. We designed a testchip in 65 nm CMOS. When compared to the baseline arbiter PUF implementation, the cost increase of our proposed architecture is 1.27x, and 2.2x when using clock randomization, and Boolean masking, respectively.