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 no modern interoperable approach allowing secure updates to firmware in IoT devices. In June of 2016 the Internet Architecture Board organized a workshop on 'Internet of Things (IoT) Software Update (IOTSU)', and RFC 8240 documents various requirements and challenges that are specific to IoT devices. A firmware update solution consists of several components, including: * A mechanism to transport firmware images to compatible 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. This group will focus on defining a firmware update solution (taking into account past learnings from RFC 4108 and other firmware update solutions) that will be usable on Class 1 (as defined in RFC 7228) devices, i.e., 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 new transport or discovery mechanisms, but may describe how to use existing mechanisms within the architecture. In particular this group aims to publish several documents, namely: * An IoT firmware update architecture that includes a description of the involved entities, security threats, and assumptions. * One or more manifest format specifications. To support specification of manifest format(s), this group will first develop the information model for the contents of a manifest. Once there is general agreement on the contents, the group will pick a small number of serialization formats such as CBOR and/or ASN.1 (and their associated cryptographic mechanisms) to encode the manifest. A small number of formats is preferred to reduce the complexity of a firmware management solution, where each IoT device would typically only support one format, but the same tool or service might support all such formats. To support a wide range of deployment scenarios, the formats are expected to be expressive enough to allow the use of different firmware sources and permission models. This group does not aim to create a standard for a generic application software update mechanism, but instead this group will focus on firmware development practices in the embedded industry. Software update solutions that target updating software other than the firmware binaries (e.g., applications) are also out of scope. This group will aim to maintain a close relationship with silicon vendors and OEMs that develop IoT operating systems.