A memory device comprises a first plurality of addressable memory locations associated with a first data storage window and a second plurality of addressable memory locations associated with a second data storage window. The memory device includes a controller that receives requests from a host device to identify the first data storage window and the second data storage window. The controller receives requests to assign a first window index value to the first data storage window and to assign a second window index value to the second data storage window. The controller receives memory commands from the host device that indicate the first window index value and at least one address. The controller accesses, based at least on the first window index value, a location associated with the at least one address within the first plurality of addressable memory locations.

A method for replacing the operating software of a limited-resource portable data carrier at a terminal includes controlling the operation of the data carrier and executing at least one function provided by the data carrier. The terminal includes new operating software, a bootstrap loader for loading new operating software, and a terminal certificate providing authorization for transmitting a loading key. In authentication of the terminal, the terminal certificate is transmitted to the data carrier and verified there and a loading key is transmitted to the data carrier. The operation control of the data carrier changes over to the bootstrap loader which deletes the present operating software of the data carrier and transmits the new operating software using the loading key from the terminal. The new operating software is then verified and activated by the bootstrap loader which transfers the control of the data carrier to the new operating software.

Disclosed herein are various techniques for preventing or at least partially securing parameterse.g., Type parametersof 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.

According to one embodiment, a memory device includes a nonvolatile semiconductor memory having physical storage areas that includes a user area externally accessible and are divided into management units and a control unit. The control unit receives a control command having a first argument to designate a sequential write area and a read command or a write command, assigns a management unit represented by an address of the read command or the write command as the sequential write area, and changes memory access control by judging whether an address of a memory access command to access the user area indicates access in the sequential write area whose size is equivalent to the management unit.