Arm Limited Arm Limited Fraunhofer SIT Vulnerabilities with Internet of Things (IoT) devices have raised the need for a solid and secure firmware update mechanism that is also suitable for constrained devices. Ensuring that devices function and remain secure over their service life requires such an update mechanism to fix vulnerabilities, to update configuration settings, as well as adding new functionality One component of such a firmware update is a concise and machine- processable meta-data document, or manifest, that describes the firmware image(s) and offers appropriate protection. This document describes the information that must be present in the manifest.