Holotags for security applications

Describes a process to generate a hologram with reduced dimensions (some mm²), the holotag, that can be, in principle, stuck to an item or engraved in it (e.g. by laser scribing). That hologram contains the information coded in a 2-D object, the patch pattern. Three coding levels are implemented in the holotag: binary coding of alphanumeric information, coding of the information pattern lay-out and the holographic coding. The techniques for coding and decoding 1 Kbit of information are described