Analysis of eSIM/iSIM for Critical Communications

The Next Generation Critical Communication (NGCC) systems will rely on mobile technologies and its services. The 4G/5G subscriber credentials have traditionally been hosted on a Subscriber Identity Module (SIM), which consists of a smartcard with a SIM application. These days one also have the option to use an embedded-SIM (eSIM) or an integrated-SIM (iSIM). The eSIM consists of a non-removable processing unit (eSIM HW) and a downloadable eSIM application. The iSIM is similar to eSIM, but the iSIM will run on a Tamper-Resistant Element (TRE) on the main chipset. The use of eSIM/iSIM makes particular sense for IoT use-cases, for instance for sensor and drones, but will be used for all types of subscribers. The change in the SIM distribution model and hosting have an impact on security. This paper investigates eSIM/iSIM security aspects and issues for the NGCC context.