Systems for preparation of a mark and authentication of a mark vis-a-vis a counterfeit mark. Emission spectra comprising intensity versus wavelength distributions are collected from a series of taggants. One or more taggants is selected from the collected emission data such that the spectra of the selected taggants are distinguishable. The selection is also based on a consideration of the emitted radiation of a substrate and a dispersive medium. The authentication system uses multivariate statistical analysis to calculate at least one measurement statistic of a mark to be authenticated and at least one statistical limit based on a series of training marks prepared by the preparation system. Authenticity of the mark is determined based on a comparison of the measurement statistic and the statistical limit.