Optically deriving information from a security element

摘要

One aspect of the invention is a method of deriving information from an optically-readable security element 85 having one or more optically-readable (OR) structures 86,87. The method comprises: optically reading the security element in response to excitation (EX1) of the OR structures, wherein the OR structures are arranged to interact with one or more proximal structures of the security element. The interaction is such that an excitation-emission relationship for the OR structures interacting with the one or more proximal structures is different to an excitation-emission relationship for the OR structures and the proximal structures in isolation (see Fig. 5). The reading comprises: determining data indicative of an optical property of the security element using first emission electromagnetic radiation, emitted in response to first excitation of the one or more OR structures; and deriving the information from the determined data. The nature and extent of interactions between structures are difficult to copy so can provide improved authentication security. Independent claims are also included for the optically-readable security element and a system for reading such an element.