Method for updating a firmware component and device of measurement and control technology

A device of measurement and control technology comprising:

• a device electronics having at least one microcontroller, the microcontroller including an embedded firmware having a first firmware component and a second firmware component, the first firmware component including
• one or more algorithms for the provision of functionalities of the device,
• an algorithm for the reception of a first firmware image, which includes a data area and a signature field, wherein the data area used for the updating of the first firmware component includes data containing a firmware program code, and wherein the signature field contains a first authentication datum produced according to a first encryption method,
• an authentication algorithm for the authentication of the first firmware image based upon the first authentication datum according to the first encryption method,
• an algorithm for the generation of a second authentication datum from the firmware program code according to a second encryption method differing from the first encryption method, and
• an algorithm for the storage of the second authentication datum in a persistent memory of the microcontroller,
• the second firmware component including
• an algorithm for the reception of a second firmware image that includes the firmware program code used for updating the first firmware component,
• an algorithm for the erasure of the first firmware component and for the storage of the firmware program code included in the second firmware image as a new first firmware component,
• an algorithm for reading the second authentication datum from the persistent memory,
• an authentication algorithm according to the second encryption method for the authentication of the second firmware image based upon the second authentication datum and the firmware program code included in the second firmware image, and
• an algorithm for enabling the new first firmware component,
• wherein the first encryption method is an asymmetric encryption method and the second encryption method is a symmetric encryption method,
• wherein the first firmware component further includes a key generator, the key generator including a random number generator and an algorithm for the storage of a key generated via the key generator for the second encryption method in a persistent memory of the microcontroller, and
• wherein the authentication algorithm according to the second encryption method is embodied to create a check sum from the generated key and the firmware program code included in the second firmware image and to compare the check sum to the second authentication datum.