As embedded computers become ubiquitous, mobile and more integrated in connectivity, user dependence on integrated circuits (ICs) increases massively for handling security sensitive tasks as well as processing sensitive information. During this process, hardware authentication is important to prevent unauthorized users or devices from gaining access to secret information. An effective method for hardware authentication is by using physical unclonable function (PUF), which is a hardware design that leverages intrinsic unique physical characteristics of an IC, such as propagation delay, for security authentication in real time. However, PUF is vulnerable to modeling attacks, as one can design an algorithm to imitate PUF functionality at the software level given a sufficient set of challenge-response pairs (CRPs).
To address the problem, we employ hardware isolation primitives (e.g., ARM TrustZone) to protect PUF. The key idea is to physically isolate the system resources that handle security-sensitive information from the regular ones. This technique can be implemented by isolating and strictly controlling any connection between the secure and normal resources. We design and implement a ring oscillator (RO)-based PUF with hardware isolation protection using ARM TrustZone. Our PUF design heavily limits the number of CRPs a potential attacker has access to. Therefore, the modeling attack cannot be performed accurately enough to guess the response of the PUF to a challenge.
Furthermore, we develop and demonstrate a brand new application for the designed PUF, namely multimedia authentication, which is an integral part of multimedia signal processing in many real-time and security sensitive applications. We show that the PUF-based hardware security approach is capable of accomplishing the authentication for both the hardware device and the multimedia stream while introducing minimum overhead.
Finally, we evaluate the hardware-isolated PUF design using a prototype implementation on a Xilinx system on chip (SoC). Particularly, we conduct functional evaluation (i.e., randomness, uniqueness, and correctness), security analysis against modeling attacks, as well as performance and overhead evaluation (i.e., response time and resource usages). Our experimental results on the real hardware demonstrate the high security and low overhead of the PUF in real time authentication.
Advisor: Sheng We
