Secure Communication through Double Layer Security with Efficient Key Transmission

Information security becomes a major concern today. The paper introduces a double layer security approach that use both cryptography and steganography for secure transmission. The secret message is first encrypted using S-DES encryption algorithm. The keys of encryption are generated from edge pixels where the encrypted message is embedded within the non-edge pixels of cover image. The capacity of the method is enhanced through multi-bit embedding in three color channels. The proper extraction of target data is ensured through the non-involvement of lower bit-planes during edge detection. The quality of the stego media is maintained within the acceptable range of PSNR even at the higher embedding capacity. The security strength of the proposed method ensures through the transmission of keys with stego image and with the use of different keys for encryption. The method also reduces the bandwidth required in double layer security for key transmission.