Security in Digital Images: Steganography and Watermarking

Digital image is one of the best media to store data. It provides large capacity for hiding secret information which results into stego-image imperceptible to human vision. Digital images are widely communicated over the internet. The security of digital images is an essential and challenging task on shared communication channel. Various techniques are used to secure the digital image, such as encryption, steganography and watermarking. Steganography is the process of art and science in such a way that no one apart from sender and intended recipient even realizes that the communication is going on. It is also used to authenticate the digital images. This paper presents a security technique using encryption, steganography and watermarking. It comprises of three key components: (1) the original image has been encrypted using large secret key by rotating pixel bits to right through XOR operation, (2) for steganography, encrypted image has been altered by least significant bits (LSBs) of the cover image and obtained stego image, then (3) stego image has been watermarked in the time domain and frequency domain to ensure the ownership. The proposed approach is efficient, simpler and secured; it provides significant security against threats and attacks.