TERO-Based Detection of Hardware Trojans on FPGA Implementation of the AES Algorithm

A Transient Effect Ring Oscillator (TERO) is a special case of a Ring Oscillator (RO) design that exhibits increased sensitivity to intrinsic noise. It can serve as a basis for implementing a True Random Number Generator (TRNG) or a Physically Uncloneable Function (PUF). Also, as a digital sensor for detecting insertion of malicious hardware logic (Trojans) in digital circuits. Here, we explore the application of TERO for detecting hardware Trojans injected in FPGA implementations of the AES cryptographic algorithm. Experiments and comparisons are reported in terms of the frequency as a function of the TERO length. Our findings indicate that TERO-based digital sensors can be used to efficiently detect the presence of the Trojan.