Thermal Effects of Dark Current on Blind Source Camera Identification

Abstract

The state of the art method for fingerprinting digital cameras focuses on the non-uniform output of an array of pixels due to the distinct construction of the PN junction when excited by photons. This photo-response non-uniformity approach has been shown to be effective but excludes knowledge of image sensor output under equilibrium states without excitation (dark current). The dark current response traditionally has been deemed unsuitable as a source of fingerprinting as it is unstable across multiple variables including exposure time and temperature. As such it is currently ignored. Since an individual photodiode is filled with a combination of dark current electrons and photo current electrons we propose that dark current can also be used to generate the fingerprint.