The art of information concealment has been around nearly as long as the need for covert communication. Steganography, the concealment of information, soon emerged as an extremely useful method for the transmission of covert information. Steganography is the art of hiding the secret message within a larger image or message in such a way that the hidden message or image is not detectable; this is in contrast to cryptography, where the existence of the message itself is not disguised, but the content is obscure. The goal of a steganographic method is to minimize visual and apparent visual differences between cover data and a steganogram while maximizing the payload size. Current digital image steganography presents the challenge of hiding messages in a digital image in a way that is robust to image manipulation and attack. This document explains how a secret message can be hidden in an image using the least significant bit insertion method along with chaos.
The techniques of concealment of the information arose to satisfy the need of a covert communication. Steganography is an extremely useful method for the transmission of covert information. Steganography is the technique of hiding data that allows hiding a secret message or an image within a larger image or message, so that the hidden message or an image is undetectable. In this article we propose a stereogenic method of hiding image, of hiding an image inside a cover image. This steganographic method aims to minimize the visually apparent and statistical differences between the cover image and an image of stego with increase in the size of the payload. The proposed algorithm uses binary codes which is the binary representation of the pixels within the image. This algorithm makes use of the least significant bit (LSB) technique, which is a popular technique in steganography, in which the least significant bits of the cover are altered by bits of secret data. The proposed method incorporates a randomization algorithm that improves the security of the LSB scheme. The bits of the secret image are embedded in random pixels of the cover image and these random pixels are generated by the RC4 algorithm. The system improves the security of the LSB technique by randomly dispersing the secret image fragments in the cover image, making it difficult for unauthorized persons to extract the original image. Since all of the secret image bits are embedded in the cover image, the exact secret image can be regenerated from the stego image and therefore the image quality is preserved by the system.