An optical storage medium having a layered structure suitable for use in security application, such as, e.g. smart cards or smart labels is disclosed. The medium comprises (a) a photoaddressable layer that includes a polymer the molecular structure of which includes at least one structural unit conforming to formula (I) and (b) substrate layer. Embodiments of the medium that further include at least one member selected from the group consisting of a transparent barrier layer, reflection layer and an adhesive layer, interposed between the photoaddressable layer and the substrate layer are also disclosed.