1. An apparatus for generating a digital value, the apparatus comprising: a generating unit to generate a plurality of digital values, the generating unit comprising a plurality of physically unclonable functions (PUFs), wherein a portion of the PUFs is implemented by applying at least one parameter causing a semiconductor process variation; and a processing unit to process the digital values and to provide a first digital value, wherein at least one of the PUFs comprises a via formed between conductive layers in a semiconductor, and wherein the parameter comprises a size of the via selected from a range between a minimum value and a maximum value of the size of the via corresponding to whether the via causes a short between the conductive layers.