Adaptive Security: Certificate and Key Rotation for Firmware Integrity

This paper provides an overview of several device architectures that allow for key rotation. Key rotation is important due to the frequency of lost signing keys, but it is difficult for Industrial Internet of Things (IIOT) devices due to limited resources during a secure boot process and the constraints of the firmware utilities that come from the chip vendors. The intent of this paper is to provide a practitioner’s perspective on this challenge and the tradeoff in hopes of inviting comments from chip vendors and the broader community.