Application of Adobe® Photoshop® CC 2018 for Identifying the Source of HP® Color Laser Printouts

In today’s digital world, printer forensics is one of the most important disciplines to reveal the authenticity of printed documents and track criminals. Digital steganography is an advanced approach to secure color laser printing processes, but it cannot be applied to monochrome laser printers. Therefore, the identity of the machine used to print color questioned documents provides a valuable means for detecting forgery crimes in digital forensic labs and law enforcement agencies. Based on this, we introduced a new forensic method that unveils the steganography (hidden information) embedded in color laser printouts via an adopted preset in Adobe® Photoshop® CC 2018. This forensic tool can be applied as a nondestructive and indirect tool for image processing. In the present work, printing, scanning, extraction, and measurements for the embedded tracking dots of candidate color laser printouts were conducted. Thirty-five HP® color laser printers were selected with different and same models with different serial numbers and used to print a hundred color laser printouts. The defined coded dots matrix patterns that characterized the color laser machines of the HP® brand could clearly be determined. Therefore, this procedure could successfully be applied to distinguish between various color laser printouts printed by HP® printers with a variant serial number in digital forensic labs with a conclusive accuracy ratio attained to one hundred percent.