Vulnerabilities in Internet of Things (IoT) devices have raised the need for a secure firmware update mechanism that is also suitable for constrained devices. Security experts, researchers, and regulators recommend that all IoT devices be equipped with such a mechanism. While there are many proprietary firmware update mechanisms in use today, there is a lack of a modern interoperable approach of securely updating the software in IoT devices. A firmware update solution consists of several components, including: * A mechanism to transport firmware images to IoT devices. * A manifest that provides meta-data about the firmware image (such as a firmware package identifier, the hardware the package needs to run, and dependencies on other firmware packages), as well as cryptographic information for protecting the firmware image in an end-to-end fashion. * The firmware image itself. RFC 4108 provides a manifest format that uses the Cryptographic Message Syntax (CMS) to protect firmware packages. More than ten years have passed since the publication of RFC 4108, and greater experience with IoT deployments has led to additional functionality, requiring the work done with RFC 4108 to be revisited. This group will focus on defining a firmware update solution for Class 1 devices, as defined in RFC 7228, that is -- IoT devices with ~10 KiB RAM and ~100 KiB flash. The solution may apply to more capable devices as well. This group will not define any transport mechanisms. In June of 2016 the Internet Architecture Board organized a workshop on 'Internet of Things (IoT) Software Update (IOTSU)', which took place at Trinity College in Dublin, Ireland. The main goal of the workshop was to foster a discussion on requirements, challenges, and solutions for bringing software and firmware updates to IoT devices. This workshop also made clear that there are challenges with misaligned incentives and complex value chains. It is nevertheless seen as important to create standard building blocks that help interested parties implement and deploy a solid firmware update mechanism. In particular this group aims to publish three documents, namely: * An IoT firmware update architecture that includes a description of the involved entities, security threats, and assumptions. * The manifest format. * A revision to RFC 4108 that reflects the current best practices. This group does not aim to create a standard for a generic software update mechanism for use by rich operating systems, like Linux, but instead this group will focus on software development practices in the embedded industry. "Software update solutions that target updating software other than the firmware binary (e.g. updating scripts) are also out of scope. This group will aim to maintain a close relationship with silicon vendors and OEMs that develop IoT operating systems.