Exploiting Power Signatures for Camera Forensics

Abstract

The electric network frequency (ENF) is a signature of power distribution networks that can be captured by multimedia signals recorded near electrical activity. This has led to the emergence of multiple forensic applications based on the use of ENF signals. Examples of such applications include validating the time of recording of an ENF-containing multimedia signal or inferring the grid in which it was recorded. In this letter, we explore a novel ENF-based application that seeks to characterize the camera that has produced a given video. Inspired by recent work on exploiting flicker for pirate device identification, we investigate the use of ENF captured in a video to characterize the camera that has produced the video through a nonintrusive procedure that estimates the camera’s read-out time. The proposed technique has achieved a high accuracy in estimating this discriminating parameter with a relative estimation error within 1.5%.