LSB Steganalysis to Detect the Embedded Message Length Using Pixel Pair Threshold

In the recent past, image steganalysis has drawn considerable attention. LSB steganography has been in use for quite sometime and researchers have focused to detect the hidden message, but have not been able to estimate accurately the length of the embedded message. In this paper, we have described an effective steganalytic tool called pixel pair analysis using fixed threshold (PPAFT) for detecting LSB steganography. First, the threshold is evaluated using both the cover image and the stego image. Then, based on statistical measures of pixel pairs, we compute the length of the embedded message. The methodology described in this paper is accurate, simple, fast and better than the existing algorithms.