Apr 7 (Wed): "On Design and Machine Learning Resiliency of Memristor- and eFlash-Memory-Based Strong Physical Unclonable Functions," Shabnam Larimian, ECE PhD Defense
The emergence of the Internet of Things (IoT) has enabled an unprecedented expansion of interconnected networks and devices over which the huge amount of personal and/or sensitive data is carried. As a result, privacy and security issues are among the most significant challenges in designing IoT devices. These challenges can hardly be addressed using conventional cryptographic approaches because they rely on storing secret keys in memories, which not only are vulnerable to physical and side-channel attacks but also consume huge area and vast amounts of power.
Hardware-based security approaches such as physical unclonable functions (PUFs) have attracted considerable attention as replacements for conventional methods. PUFs are well suited to a wide spectrum of security applications including key generation and authentication because they generate secure keys on the fly (rather than explicitly storing any security-critical information). This is achieved by utilizing electronic devices that entail inherent sources of randomness, which in turn help create unique keys for different physical entities.
Recently, a variety of emerging nano-scale non-volatile memories are being explored for use in the design of PUFs including memristors and embedded flash (eFlash) memories. The highly non-linear current-voltage characteristics and the inherent process variations of these memory devices make them promising candidates for designing PUFs. Additionally, the ultra-low power consumption and low computation time of these devices enable their use in applications with stringent requirements on energy-efficiency and throughput.
This dissertation presents memristor- and eFlash-memory-based PUF designs that show promising security characteristics such as near-to-ideal uniformity, diffuseness, robustness, and reliability. Additionally, it verifies the high output randomness of these designs by passing the test suits of the National Institute of Standards and Technology. This dissertation further tests the designed PUFs for robustness by applying machine learning attacks, which are currently the most effective form of attack against strong PUFs.
Furthermore, this dissertation investigates several unexplored aspects of PUFs such as finding the secure PUF characteristics, the impact of the capacity of machine learning models on robustness, and the impact of environmental change and thermal noise on reliability. Additionally, this dissertation proposes a balancing heuristic that can significantly improve PUF security against machine learning attacks when the PUF devices are nonuniform or there is a stuck-at-fault device. Finally, the thesis presents methodologies to prevent possible information leakage through tuning circuits and power supply.
Shabnam Larimian is a Ph.D. candidate in Professor Strukov’s group. She is interested in the applications of machine learning.
Hosted by: Professor Dmitri B. Strukov
Submitted by: Shabnam Larimian