| CPC G07D 7/1205 (2017.05) | 12 Claims |

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1. A method for determining an authenticity of an object, comprising the following steps:
marking the object with a first luminescent material with a first decay behavior over time,
marking the object with a second luminescent material with a second decay behavior that differs from the first decay behavior,
exciting the first and second luminescent materials with a light pulse,
measuring an afterglow intensity of both the first and second luminescent materials after the exciting with the light pulse,
forming a difference signal or identity signal from the afterglow intensities, measured over an elapsed time,
determining a time of a zero crossing of the difference signal or a time of the identity signal of a comparator, and,
comparing the time determined by the zero crossing or by the identity signal with a setpoint value.
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