Martina Zeinzinger

Martina Zeinzinger, Josef Langer, Florian Eibensteiner et al.

An SRAM Physical Unclonable Function (PUF) can distinguish SRAM modules by analyzing the inherent randomness of their start-up behavior. However, the effectiveness of this technique varies depending on the design and fabrication of the SRAM module. This study compares two similar microcontrollers, both equipped with on-chip SRAM, to determine which device produces a better SRAM PUF. Both microcontrollers are programmed with an identical SRAM PUF authentication routine and tested under varying ambient temperatures (ranging from 10 °C to 50 °C) to evaluate the impact of temperature on SRAM PUF performance. One embedded SRAM works significantly better than the other, even though the two models are closely related. The presented results can be used early in the design process to compare arbitrary on-chip SRAM models and see which is best suited for implementing an SRAM PUF.

Bernhard Fischer, Daniel Dorfmeister, Flavio Ferrarotti et al.

Embedded software used in industrial systems frequently relies on data that ensures the correct and efficient operation of these systems. Thus, companies invest considerable resources in fine-tuning this data, making it their valuable intellectual property (IP). We present a novel protection mechanism for this IP that combines hardware fingerprints with Boolean logic. Unlike usual copy-protection approaches, unauthorised copies of the software still run on cloned devices but suboptimally. According to our security evaluation, only a complex dynamic analysis of the protected software running on the genuine target device can reveal the secret data. This makes the protection offered by our method more difficult to bypass. Notably, our approach does not require additional hardware, relying only on relatively simple updates to the software. We evaluate our protection mechanism by binding the parameters of a PID controller to a microcontroller unit (MCU) by using a physically unclonable function (PUF) based on its SRAM.