A method for security purposes with the acts of: - requesting a measurement on a physical system wherein the measurement is performed by applying a challenge signal to the system and by receiving a response signal dependent on a setting of the challenge signal and dependent on the inner structure of the object and by determining a characteristic of the response signal, - receiving the characteristic of the response signal, wherein the characteristic of the response signal is validated by determining the time elapsed for the measurement and by performing a verification process of the response using a description of the system, wherein the complexity of the inner structure of the physical system ensures that the time needed for the verification process is longer than the time elapsed for the measurement.     «

A method for security purposes with the acts of: - requesting a measurement on a physical system wherein the measurement is performed by applying a challenge signal to the system and by receiving a response signal dependent on a setting of the challenge signal and dependent on the inner structure of the object and by determining a characteristic of the response signal, - receiving the characteristic of the response signal, wherein the characteristic of the response signal is validated by determi...     »