Security document with integrated authentication system

摘要

Security document with an authentication comprising a transparent window and a security element, where the security element cannot be photocopied and is located outside the transparent window. The transparent window co-operates with the security element to modify its appearance when viewed across the transparent window. Preferably, the security element is printed with one or more coloured inks and the window has light filtering properties to allow passage of only the wavelength corresponding to the ink colour.