A method, apparatus and system for analysing and authenticating a luminescent tag are provided wherein a luminescence is triggered in the tag and relative light intensities emitted thereby measured within at least two luminescence bands. The measured intensities are compared with at least one reference tag representative of relative intensities emitted by an authentic tag to determine whether the luminescent tag corresponds with any of the at least one reference tag. If the measured intensities match the representative intensities, the luminescent tag is authenticated. A computer program to be implemented by the apparatus and system is also disclosed. Further, a method and system for verifying the authenticity of one or plural objects are disclosed, wherein each of the objects is to be associated with a respective tag. The respective tags are coded to emit light, when triggered, within at least two luminescence bands at respective predetermined relative light intensities. Having access to a reference tag representative of the predetermined intensities, the authenticity of a luminescent tag is verified by measuring intensities emitted thereby within the luminescence bands and comparing the measured intensities with the predetermined intensities.