Detecting Steganographic Messages in Digital Images
Hany Farid · 2001
Introduction Information hiding techniques (e.g., steganography and watermarking) have recently received quite a bit of attention (see [9, 1, 7, 12] for general reviews). At least one reason for this is the desire to protect copyrights of digital audio, image and video. Other applications include unobtrusive military and intelligence communication, covert criminal communication, and the protection of civilian speech against repressive governments. Along with new and improved techniques for hiding information will come techniques for detecting (and possibly removing) such information. Although messages embedded into an image are often imperceptible to the human eye, they often disturb the statistical nature of the image. Previous approaches to detecting such deviations [8, 23, 13, 15] examine first-order statistical distributions of intensity or transform coefficients (e.g., discrete cosine transform, DCT). In contrast, the approach to detection taken here relies on building highero