1. A method for authenticating an authentic article having an authentication mark, comprising the steps of: (a) acquiring a set of hyper-spectral images of at least a part of the authentication mark, by using a spectral imaging and analysis system operative according to a hyper-spectral mode of spectral imaging and analysis; (b) forming a set of single-authentication mark hyper-spectral fingerprint data from said set of acquired hyper-spectral images of said hyper-spectrally imaged authentication mark; (c) identifying at least one spectral shift in said set of single-authentication mark hyper-spectral fingerprint data associated with said hyper-spectrally imaged authentication mark, for forming an intra-authentication mark physicochemical region group including a plurality of sub-sets of intra-authentication mark hyper-spectral fingerprint pattern data, such that value of at least one selected data element in each said sub-set is shifted relative to value of each corresponding said data element in each remaining said sub-set in same said intra-authentication mark physicochemical region group; (d) forming a set of intra-authentication mark physicochemical properties and characteristics data relating to said hyper-spectrally imaged authentication mark, by performing pattern recognition and classification analysis on said intra-authentication mark physicochemical region group of said hyper-spectrally imaged authentication mark; and (e) comparing and matching values of elements in said set of intra-authentication mark physicochemical properties and characteristics data relating to said hyper-spectrally imaged authentication mark to values of corresponding reference elements in a reference set of intra-authentication mark physicochemical properties and characteristics data of the authentic article, thereby authenticating the authentic article.