Method for personalizing a secure element that is fixedly installed in a mobile terminal, the personalization comprising equipping the secure element with an operating system able to be executed in the secure element, the method comprising the following steps: (a) providing the secure element and, before the secure element is fixedly installed in the mobile terminal, providing a private SE key of an asymmetric SE key pair in the secure element, and providing the public SE key of the same asymmetric SE key pair in a hardware security module arranged outside the secure element; (b) after providing the private SE key to the secure element and the public SE key to the hardware security module, providing the secure element to a manufacturer of the mobile terminal and fixedly installing the secure element in a mobile terminal; (c) in the hardware security module, generating or providing an asymmetric HSM key pair comprising a public HSM key and a private HSM key; (d) in the hardware security module, based on the private HSM key and the public SE key, deriving a secret shared with the secure element, which secret is in the form of at least one symmetric key; (e) in the hardware security module, providing an operating system packet including at least one operating system - or at least part of an operating system - and encrypting at least the operating system packet using a transport key that is formed by the shared secret or part thereof, or that is derived from the shared secret, in order to generate an encrypted operating system packet; (f) in the hardware security module, generating a memory image (BLOB) suitable and configured for programming the secure element, the memory image including at least the encrypted operating system packet and the public HSM key; (g) operating a data connection between the hardware security module and the secure element and transmitting the memory image (BLOB) from the hardware security module to the secure element fixedly installed in the mobile terminal; (h) in the secure element, extracting the public HSM key from the memory image (BLOB) and, based on the private SE key and the public HSM key, deriving the shared secret and the transport key and decrypting the encrypted operating system packet using the transport key; (i) in the secure element, providing, generating or deriving a symmetric NVM encryption key individual to the secure element and different from the transport key, and encrypting the decrypted operating system packet using the NVM encryption key; (j) using the secure element to store the operating system packet that is decrypted and encrypted again with the individual symmetric NVM encryption key in an NVM memory of the mobile terminal that is arranged outside the secure element, wherein, as a result of the operating system packet being stored in the NVM memory, the secure element is provided with an operating system able to be executed in the secure element. (a) providing the secure element and, before the secure element is fixedly installed in the mobile terminal, providing a private SE key of an asymmetric SE key pair in the secure element, and providing the public SE key of the same asymmetric SE key pair in a hardware security module arranged outside the secure element; (b) after providing the private SE key to the secure element and the public SE key to the hardware security module, providing the secure element to a manufacturer of the mobile terminal and fixedly installing the secure element in a mobile terminal; (c) in the hardware security module, generating or providing an asymmetric HSM key pair comprising a public HSM key and a private HSM key; (d) in the hardware security module, based on the private HSM key and the public SE key, deriving a secret shared with the secure element, which secret is in the form of at least one symmetric key; (e) in the hardware security module, providing an operating system packet including at least one operating system - or at least part of an operating system - and encrypting at least the operating system packet using a transport key that is formed by the shared secret or part thereof, or that is derived from the shared secret, in order to generate an encrypted operating system packet; (f) in the hardware security module, generating a memory image (BLOB) suitable and configured for programming the secure element, the memory image including at least the encrypted operating system packet and the public HSM key; (g) operating a data connection between the hardware security module and the secure element and transmitting the memory image (BLOB) from the hardware security module to the secure element fixedly installed in the mobile terminal; (h) in the secure element, extracting the public HSM key from the memory image (BLOB) and, based on the private SE key and the public HSM key, deriving the shared secret and the transport key and decrypting the encrypted operating system packet using the transport key; (i) in the secure element, providing, generating or deriving a symmetric NVM encryption key individual to the secure element and different from the transport key, and encrypting the decrypted operating system packet using the NVM encryption key; (j) using the secure element to store the operating system packet that is decrypted and encrypted again with the individual symmetric NVM encryption key in an NVM memory of the mobile terminal that is arranged outside the secure element, wherein, as a result of the operating system packet being stored in the NVM memory, the secure element is provided with an operating system able to be executed in the secure element.