Image Steganography by Using Exploiting Modification Direction and Knight Tour Algorithm

Abstract

In  this study, a new technique for information hiding have been proposed by using Exploiting Modification Direction (EMD) technique and enhanced it by using Knight Tour algorithm for embedded the information within the image and by using LZW for encrypt and compress the secret message. In this technique, LZW have been used for  the purpose of encrypted, compressed and transformed  the characters of secret message into stream of bits for the purpose of protect and reduce the size of the message. In the next step, the EMD technique and Knight tour algorithm have been used to embed the secret digits where the cover image is segmented into groups. Each group have 4 pixels. Afterward, the image is segmented into blocks size (4*4) group for each block. The (2n+1)-ary notational system is used to represent the secret digits for the message  that embedded within image. To increase the robustness and the security for the proposed method the Knight tour algorithm is used to select which group can be used to hide the secret digit. Where, one secret digit  is embedded by modifying one gray-scale value for the particular pixel inside the group by using EMD technique. Afterward, the statistical attacks by using x² method is applied on the stego image to assess the robustness of the proposed method against the attacks. The experimental results have depicted that the PSNR and the Payload of proposed method is better than the previous methods that used in Steganography.