Apparatus for Communicating a Signal According to a Communication Model and Network Node Comprising the Apparatus

The invention describes an apparatus (10) for communicating a signal according to a communication model (1 1 ) which is described by a plurality of layers (16; 16; 22; 24; 26;28), each layer (16; 16; 22; 24; 26; 28) describing a subset of a functionality of the communication model. The apparatus comprises a first hard-wired circuit (21; 23; 25; 27) which at least partially implements a functionality of a first layer (22; 24; 26; 28) of the plurality of layers (16; 16; 22; 24; 26; 28; 32) and a hard-wired encryption circuit (31 ) for encrypting or decrypting the signals to be communicated.