This document discusses the role of eSIM in new IoT security services. It begins by providing background on eSIM and SIM technology. It then outlines several ways eSIM can enhance IoT security, including: 1) Enabling zero-touch authentication of IoT devices in third-party services by leveraging the proven authentication of SIMs in cellular networks. 2) Hardening data encryption using the eSIM as a root of trust by generating encryption keys within the secure element of the eSIM. 3) Potential future roles like integrating the eSIM with threat detection to trigger authorization actions, and increasing the robustness of remote attestation through eSIM cryptographic abilities. The document argues