Disclosed herein are various techniques for preventing or at least partially securing parameters—e.g., Type parameters—of electronic Subscriber Identity Modules (eSIMs) stored within an embedded Universal Integrated Circuit Card (eUICC) from being inappropriately modified by mobile network operators (MNOs). One embodiment sets forth a technique that involves modifying file access properties of the Type parameters of eSIMs to make the Type parameters readable, but not updatable by the MNOs. Another embodiment sets forth a technique that involves implementing eSIM logical containers that separate the Type parameters from the eSIM data within the eUICC, such that the Type parameters are inaccessible to the MNOs. Yet another embodiment sets forth a technique that involves implementing an Operating System (OS)-based registry that is inaccessible to the MNOs and manages Type parameters for the eSIMs that are stored by the eUICC.