Method for authenticity testing of a safety feature containing an anti-Stokes fluorescent material in which the wavelength of an electromagnetic emission is shorter than the wavelength of an absorbed electromagnetic excitation radiation, comprising the following steps: a) in a calibration mode: - excitation of a plurality of calibration patterns of the safety feature by means of the excitation radiation for an excitation period and subsequent termination of the excitation, wherein the excitation period comprises at least one response phase and one decay phase; - recording the emission responses of the calibration patterns over time and selection of a plurality of emission responses of different calibration patterns; - determining the slope of the selected emission responses; - specifying a first control time (τ on) in the response phase before reaching the saturation intensity and a second control time (τ off) in the decay phase after the excitation has ended; - specifying a first validity value corresponding to the maximum value of the slope of the selected calibration patterns at the first control time (τ on) and a second validity value corresponding to the maximum value of the slope of the selected calibration patterns at the second control time (τ off); b) in a test mode: - excitation of the safety feature to be tested by means of the excitation radiation over the excitation period and subsequent termination of the excitation; - recording the emission response of the safety feature to be tested at least at the first control time (τ on) and at the second control time (τ off); - determining the slope of the recorded emission response; - classifying the security feature to be checked as "genuine" if the slope values at the first control time (τ on) are not greater than the first validity value and at the second control time (τ off) not greater than the second validity value. a) in a calibration mode: - excitation of a plurality of calibration patterns of the safety feature by means of the excitation radiation for an excitation period and subsequent termination of the excitation, wherein the excitation period comprises at least one response phase and one decay phase; - recording the emission responses of the calibration patterns over time and selection of a plurality of emission responses of different calibration patterns; - determining the slope of the selected emission responses; - specifying a first control time (τ on) in the response phase before reaching the saturation intensity and a second control time (τ off) in the decay phase after the excitation has ended; - specifying a first validity value corresponding to the maximum value of the slope of the selected calibration patterns at the first control time (τ on) and a second validity value corresponding to the maximum value of the slope of the selected calibration patterns at the second control time (τ off); - excitation of a plurality of calibration patterns of the safety feature by means of the excitation radiation for an excitation period and subsequent termination of the excitation, wherein the excitation period comprises at least one response phase and one decay phase; - recording the emission responses of the calibration patterns over time and selection of a plurality of emission responses of different calibration patterns; - determining the slope of the selected emission responses; - specifying a first control time (τ on) in the response phase before reaching the saturation intensity and a second control time (τ off) in the decay phase after the excitation has ended; - specifying a first validity value corresponding to the maximum value of the slope of the selected calibration patterns at the first control time (τ on) and a second validity value corresponding to the maximum value of the slope of the selected calibration patterns at the second control time (τ off); b) in a test mode: - excitation of the safety feature to be tested by means of the excitation radiation over the excitation period and subsequent termination of the excitation; - recording the emission response of the safety feature to be tested at least at the first control time (τ on) and at the second control time (τ off); - determining the slope of the recorded emission response; - classifying the security feature to be checked as "genuine" if the slope values at the first control time (τ on) are not greater than the first validity value and at the second control time (τ off) not greater than the second validity value. - excitation of the safety feature to be tested by means of the excitation radiation over the excitation period and subsequent termination of the excitation; - recording the emission response of the safety feature to be tested at least at the first control time (τ on) and at the second control time (τ off); - determining the slope of the recorded emission response; - classifying the security feature to be checked as "genuine" if the slope values at the first control time (τ on) are not greater than the first validity value and at the second control time (τ off) not greater than the second validity value.