An enhanced and secure image steganographic technique using RGB-box mapping

Image steganography is a technique of masking secret information (e.g. text, image, audio, video etc.) in a cover image in order to protect the information from being modified or destroyed. Owing to its simplicity and hiding capacity, Least Significant-Bit (LSB) insertion in spatial domain techniques is a very popular approach of hiding information in a cover image. This paper presents a new algorithm to hide a RGB image in another RGB image based on LSB insertion technique. The concept of mapping is applied on RGB images for making it more secure. Two different key-boxes for each channel are used for mapping. Each of these two key-boxes for a channel have 4 different values which are used to map the pixel values of that channel of secret image to 3 LSB bits of corresponding channel of cover image. The proposed method provides extra security as without the knowledge of mapping technique, it is not possible to extract the secret information. Further, the hiding capacity is good and the quality of stego-image is improved by using fewer number of LSB bits for hiding the secret information.