Methods for Providing High Security to Transfer Secret Image [ ]


Privacy and security of data being transmitted has become the major issue. Now a day’s one of the major challenge is transfer of data securely through the secure communication channel. Many images transmitted via Internet containing secret information but not secure. In Visual cryptography technique, the secret image is initially partitioned into different shares. The shares may be meaningful or meaningless. The receiver can get the original image only after combining specified number of shares. Here each individual image does not give any information about the secret. To transfer the secret, which is in the form of image, the visual cryptography technique is more suitable. Different algorithms already proposed in visual cryptography by considering the security level. Multi layer security approach is used to increase the security level. Along with Symmetric and asymmetric algorithm, Visual Cryptography method is also considered for more security. In this paper, a visual secret sharing scheme is used so that the secret image can hide into share images with pixel expansion. An extra confidential image is embedded in the share images. Share images are encrypted using DES algorithm. Extra confidential image is also used for check the validity of reconstructed secret image. At the receiver side, receiver has to decrypt two shares and stack them to get secret image. In another method, the secret image is encrypted using Arnold’s transformation in the first step. Two shares are created using basic (2, 2) method in the second step. In the third level of security, shares are embedded in two host images. On the receiver end, shares are extracted from camouflage image and then stacked to get the encrypted image. Encrypted image is decrypted using Arnold’s Inverse Transformation These two proposed methods definitely increase the level of security.