Abstract: A method for either or both initializing and personalizing a portable data carrier having an electronic circuit, a data transmission device and a switching device. The method is characterized in that either or both before the initialization and personalization is carried out a bridging of the switching device is formed and after either or both the initialization and personalization has been carried out the bridging is eliminated.

Abstract: The invention relates to a method for personalizing a security element (SE) of a mobile end device (EG), in particular in the form of a smart card chip of a communication end device. The invention comprises the pre-personalizing of the security element (SE) within the framework of its production process and the final personalizing of the security element (SE) upon the first-time use of the end device (EG) by a user (N), wherein a communication link is established between the end device (EG) and a trust center (TC) of a communication network operator. Within the framework of the pre-personalization of the security element (SE), a master key (MK) unique to the security element (SE) is ascertained and transmitted to the trust center (TC). Within the frame-work of the final personalization of the security element (SE), personal data of the user are transmitted upon the first-time use of the end device (EG) to the trust center (TC) and linked there with the master key (MK) to form a modified master key (MK).

Abstract: The invention relates to a method for initializing and/or personalizing a portable data carrier (1) having an electronic circuit (3), a data transmission device (4) and a switching device (5). The method according to the invention is characterized in that before the initialization and/or personalization is carried out a bridging of the switching device (5) is formed and after the initialization and/or personalization has been carried out the bridging is eliminated.