A Secure Image Steganography Using LSB Technique and Random Pseudo Random Encoding Technique

Abstract

Steganography is derived from the Greek word steganographic which means covered writing. It is the science of embedding information into cover objects such as images that will escape detection and retrieved with minimum distortion at the destination. The goal of steganography is to hide the existence of the message from a third party. The modern secure image steganography presents a challenging task of transferring the embedded information to the destination without being detected. Many dierent carrier le formats can be used, but digital images are the most popular because of their frequency on the Internet. For hiding secret information in images, there exist a large variety of steganographic techniques some are more complex than others and all of them have respective strong and weak points. In this paper we present an image based steganography that combines Least Signicant Bits (LSB) techniques and pseudo random encoding technique on images to enhance the security of the communication. In the LSB approach, the basic idea is to replace the Least Signicant Bits (LSB) of the cover image with the Most Signicant Bits (MSB) of the messages to be hidden without destroying the property of the cover image signicantly. The LSB-based technique is the most challenging one as it is dicult to dierentiate between the cover-object and stego- object if few LSB bits of the cover object are replaced. In Pseudo-Random technique, a random-key is used as seed for the Pseudo-Random Number Generator is needed in the embedding process [19]. Both the techniques used a stego-key while embedding messages inside the cover image.By using the key, the chance of getting attacked by the third party is reduced.