Embedded Subscriber Identity Module eSIM

The embedded subscriber identity module (eSIM) is a ‘‘small trusted hardware component, which may be soldered into [..] devices [...], to run the secure network access application(s) [...] and enable the secure changing of subscription identity and other subscription data’’ (GSMA 2011, p. 4). The eSIM performs the same task as a traditional SIM, which is the identification and authentication of users seeking access to a mobile radio network. However, with the eSIM, a user’s identification module is no longer personalized for a single application at the time of the card’s manufacturing. Instead, the eSIM relies on a late personalization process, which is carried out remotely over the air when the access seeker calls up eSIM functions for the first time and subsequently (Oberender 2015). Thus, eSIMs enable users to (1) switch between multiple contracts and/or providers on a single appliance without having to exchange a hardware component and (2) employ multiple appliances with one contract without the need to manage the integration of various SIM cards functioning independently. There are three categories of eSIM use cases, namely (1) machine-to-machine (M2M), (2) machine-to-person (M2P), and (3) hybrid M2M plus M2P telecommunication. The M2M category comprises all applications which establish connections and exchange data automatically without any mandatory interaction with humans. Examples for M2M uses are car connections to a back-end system for vehicle tracking, remote machine maintenance, and connected house alarm systems. In contrast, in the M2P segment, radio network-based services involve deliberate human user interactions with an eSIM device, which enables its owner both to communicate with another person and to process information made available by technical systems (e.g., an Internet server). Smartphones are part of this segment as well as tablets, connected TV set-top boxes, health trackers, watches, or other electronic consumer equipment. In hybrid M2M plus M2P applications, a module in a technical system, whose primary purpose is not to enable interpersonal communication, connects automatically with other machines but at the same time allows humans to interact with the system either to directly retrieve information or to use telecommunication services. An example for a hybrid M2M plus M2P use case are cars, which connect automatically to back-end systems in an emergency event and additionally enable passengers to manually access telecommunication services. eSIMs have several design advantages over traditional SIM cards. The eSIM consumes less space as well as energy, and works in harsh conditions (e.g., extreme temperatures, pressure, humidity) (Vesselkov et al. 2015). This makes it possible to manufacture smaller, more lightweight, and robust connected technical systems. Furthermore, use cases that require more than one identification Accepted after one revision by Prof. Dr. Weinhardt.