Firmware Integrity Protection: A Survey

Over the last years, firmware integrity protection has significantly been addressed in various contexts such as internet of things, vehicles, wireless sensor networks and other systems. However, due to variety of studied systems, the proposed approaches often make divergent and sometimes even conflicting security assumptions. In this regard, we propose in this article a complete survey of the most relevant approaches addressing the firmware integrity protection regardless the considered system or field of application. We first organize the approaches in three main categories, depending on the protection type: 1. secure update, 2. attestation, and 3. secure boot. We then propose two new taxonomies, the first one concerns secure update mechanisms and the second one considers secure boot. Moreover, we extend the scope of an existing taxonomy for attestation mechanisms by studying new approaches and discussing limitations. Finally, we identify open research challenges and then give suggestions and guidelines on how to address them.