GENERATING A NONDETERMINISTIC TO A CHALLENGE According to a first aspect of the present invention, there is provided adevice for generating a nondeterministic responseto a challenge, the device comprising:a plurality of structures, each structure exhibiting quantum mechanical confinement, and each structure being arranged to provide a unique response when challenged with an electrical measurement, the unique response being linked to the atomic makeup of the structure that defines the quantum mechanical confinement; the device being arranged to facilitate a challenge of a structure of the plurality, by facilitating an electrical measurement of an output of the structure;the nondeterministic response being derivable from the electrical measurement.