Abstract: According to a first aspect of the invention, there is provided a device for generating a unique response to 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 at least two structures of the plurality in electrical combination to generate the unique response, by facilitating an electrical measurement of an output of the at least two structures of the plurality in electrical combination; the unique response being derivable from the electrical measurement.

Abstract: According to a first aspect of the present invention, there is provided a method of determining a unique identifier for a security element, the method comprising: optically reading the security element, the security element comprising a number of emitters that are each capable of exhibiting a different emission response to excitation of the number of emitters; the reading comprising determining data indicative of an optical property of the security element using first emission electromagnetic radiation, emitted in response to first excitation of the number of emitters, and determining data indicative of an optical property of the security element using second emission electromagnetic radiation, emitted in response to second, different, excitation of the number of emitters; and the unique identifier being determined from a map of a variation in determined data indicative of an optical property with respect to the excitation of the number of emitters.

Abstract: According to a first aspect of the present invention, there is provided a method of determining a unique identifier for a security element, the method comprising: optically reading the security element, the security element comprising a number of emitters that are each capable of exhibiting a different emission response to excitation of the number of emitters; the reading comprising determining data indicative of an optical property of the security element using first emission electromagnetic radiation, emitted in response to first excitation of the number of emitters, and determining data indicative of an optical property of the security element using second emission electromagnetic radiation, emitted in response to second, different, excitation of the number of emitters; and the unique identifier being determined from a map of a variation in determined data indicative of an optical property with respect to the excitation of the number of emitters.

Abstract: According to a first aspect of the invention, there is provided a device for generating a unique response to 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 at least two structures of the plurality in electrical combination to generate the unique response, by facilitating an electrical measurement of an output of the at least two structures of the plurality in electrical combination; the unique response being derivable from the electrical measurement.