1. A system for identifying a spatial code applied to an object, where the spatial code includes a plurality of security tags having one or more characteristic emission spectral profiles, the system comprising: a beam source operable to illuminate said spatial code, to stimulate light emission from the security tags in the code, simultaneously from the entire code, a detector operable to record the light emission from the security tags, at each of a plurality of wavelengths, when the code is illuminated by said source, the detector further comprising (a) an image detector for recording the spatial image of light emission from the tars in the code, (b) an optical spectrometer for recording the emission profile of the tags in the code, at each of a plurality of wavelengths, and (c) a beam splitter for splitting emitted light from the code to both the image detector and the optical spectrometer, and a processor, coupled to the detector, which is operable to (i) decode the spatial code using the spatial information, (ii) resolve the emission spectral profiles from the security tags to derive spectral information therefrom, by resolving the spectrum into a plurality of wavelengths, and (iii) identify the spatial code on the basis of the combined spatial and spectral information from (i) and (ii).