SEALSQ Provisioning in IoT is a device identity provisioning service that enables secure identity, encryption, and authentication for IoT devices through PKI infrastructure. The service provides unique identities from IoT PKI to encrypt communications and authenticate devices with IoT platforms, applications, and other devices. The solution supports two primary provisioning approaches: factory floor provisioning and cloud-based field provisioning. Factory floor provisioning binds device identities during the manufacturing process, taking advantage of secure hardware and removing supply chain bottlenecks. Cloud-based field provisioning enables scalable deployment for millions of devices by providing minimal identity at manufacturing time and completing the identity when the device is first installed in the field. The platform includes zero-touch provisioning capabilities that enable automatic and secure device onboarding to IoT cloud platforms using X.509 authentication technology. This is achieved through enrollment of local certificates (LDevID) that attest device ownership and enable automatic provisioning and authentication to the cloud. SEALSQ operates a WebTrust certified PKI infrastructure that covers people, processes, infrastructure, and the solution itself. The service supports flexible CA hierarchy configurations and provides lifecycle operations including certificate enrollment, issuance, renewal, and revocation. The platform includes a secure web portal for configuration and tracking, REST APIs for integration with business applications, and a lightweight C-Agent for device-side operations. The service has provisioned device identities in 1.5 billion devices worldwide and supports various trust configurations involving multiple CA levels.