A Technique Using PUFs for Protecting Circuit Layout Designs against Reverse Engineering

Abstract

Recently, considerable interests have been focused on Physically Unclonable Functions (PUFs) as an anti-counterfeiting technology for Integrated Circuits (ICs). PUFs are used for more secure authentication mechanisms than conventional ones, and enable us to distinguish genuine from counterfeit ICs. However, sophisticated reverse-engineering approaches, which diminish intellectual property (IP), have still been a big problem for IC designs except PUFs. The IC designs include various circuits such as audio-video-processing circuit, communication circuit, etc., which are based on their manufactures’ trade secrets. Hence the counterfeit production and information leakage through the reverse engineering of such valuable circuits are major threats to IC manufactures. In this paper, we use PUFs not for authentication but for protection of IP of IC designs. We propose a new method of the IP protection, by using HCI-SA (Hot Carrier Injection-Sense Amplifier) PUFs proposed in 2013. The HCI-SA PUF, one of the memory-based PUFs, has two great properties: one is that its response has a perfect reliability, and another is that the value of response can be fully controlled by manufactures. We design various logic gates (e.g. NAND, XOR) by using the HCI-SA PUFs, which is completely identical and impossible to be distinguished from the IC layout information. These PUF-based logic gates make ICs more resistant to a reverse-engineering attack.