Intrinsic fingerprints for image authentication and steganalysis

Abstract

With growing popularity of digital imaging devices and low-cost image editing software, the integrity of image content can no longer be taken for granted. This paper introduces a methodology for forensic analysis of digital camera images, based on the observation that many in-camera and post-camera processing operations leave distinct traces on digital images. We present methods to identify these intrinsic fingerprint traces of the various processing operations and employ them to verify the authenticity of digital data. We develop an explicit imaging model to characterize the properties that should be satisfied by a direct camera output, and model any further processing applied to the camera captured image by a manipulation filter. Utilizing the manipulation filter coefficients and reference patterns estimated from direct camera outputs using blind deconvolution techniques, the proposed methods are capable of detecting manipulations made by previously unseen operations and steganographic embedding.