Sub-surface laser encoding of physical objects for enhanced privacy and digital security

抄録

We present an improved method for encoding digital information in plastic objects using embedded bulk marking by tightly focused pulses of an infrared nanosecond laser. The marking consists of a machine-readable pattern of laser damage spots in the sub-surface region of the object. Compared to surface marking by printing or laser ablation, this method presents the advantage of improved durability of the code. This easy to implement method is suitable for marking the types of objects or their parts as well as of local positions on their surface. In particular location-aware information encoding using this method would provide novel opportunities to enhance the document security, since it prevents unwanted alteration of the initial data.