We present an authenticable graphical barcode symbology, and describe a system for its reliable encoding and decoding. The graphical barcode is generated by modulating halftone patterns according to the message to be embedded in the barcode during the rendering of a base image. The generated barcode has the appearance of the base image, and when it is printed and scanned back in, the message can be retrieved. A graphical indicium is a graphical barcode embedded with a digitally signed message such that the integrity and authenticity of the message can be verified. 1

Avi Levy

Chit Wei (nick Saw