An apparatus for accessing an encrypted memory portion of a memory is provided. The apparatus includes a plurality of signature generators, wherein each signature generator of the plurality of signature generators is configured to generate a signature of a plurality of signatures depending on an instruction of a plurality of instructions, wherein each of the plurality of instructions is a processor instruction for controlling a processor. Moreover, the apparatus includes a key modifier for generating a processed key depending on a standard key and on the plurality of signatures. Furthermore, the apparatus includes a controller for accessing the encrypted memory portion of the memory, wherein the memory access controller is configured to employ the processed key to access the encrypted memory portion of the memory.