IJRET: International Journal of Research in Engineering and Technology eISSN: 2319-1163 | pISSN: 2321-7308 __________________________________________________________________________________________ Volume: 03 Issue: 04 | Apr-2014, Available @ http://www.ijret.org 129 NESTING OF FIVE MODULUS METHOD WITH IMPROVED LSB SUBTITUTION TO HIDE AN IMAGE IN IMAGE Praneeta Dehare 1 , Sheela Verma 2 1 M.E (CTA) Scholar, Department of Computer Science & Engineering, SSGI, SSTC, Bhilai, Chhattisgarh, India 2 Assistant Professor, Department of Computer Science & Engineering, SSGI, SSTC, Bhilai, Chhattisgarh, India Abstract Steganography refers to the process of hiding secret message inside an appropriate multimedia carrier e.g. image, audio and video files. Today, by using of wireless communication more data are available electronically, which can leak from the medium where the data transmission takes place. The goal of steganography is to communicate very securely, which is completely undetectable from the medium. In this paper image steganography has used, where a secret image can transfer within an image called cover image. To hide a secret image in cover image, both the images embedded by using two techniques. The first algorithm called five modulus methods applied on the half of the both images (Secret and Cover Image) and rest of the parts of images embedded with improved LSB substitution technique. A private stego-key is also used on half parts of both images while applying FMM algorithms to make the detection of secret image from the cover image more difficult for any unauthorized recipients. The paper uses two algorithms for embedding the both secret and cover images, so for nesting of two algorithms make it difficult for any opponent (who has not involved in communication parties) to extract the hidden image from cover image. Keywords: Image Steganography, Cryptography, Five Modulus Method, Improved LSB Substitution, Security. -----------------------------------------------------------------------***----------------------------------------------------------------------- 1. INTRODUCTION In today's electronic era, steganography is an art and science of hidden communication. The word steganography is of Greek origin and means "concealed writing" from the Greek words where steganos stands for covered or protected and graphei is for writing, which originated as far back as 440(B.C.). Steganography is an ability to hide information in cover media, so that no one apart from the intendant recipients even knows that the message transmission is taking place. Through the development of electronic devices, the rapid growth of wireless communication has increased. Security and privacy in these wireless communications has desired when any secret or confidential information has shared between two parties. Many hackers try to attack on channels where the data transmission has processed. So the possibility of intrusion increased when the systems used internet extensively. Therefore sharing information via internet becomes a major issue for user and developers. To overcome on this problem steganography has used through various digital media like text, image, audio and video files. The advantage of steganography over cryptography is that the steganography hides the existence of communication, where cryptography allowed the unintended recipients to detect the transmission of information on channel; it only keeps the contents of a message secret. Secret information can be hidden inside any cover information. To explain the procedure R. Doshi, P. Jain and L. Gupta [5] provides a generic description of the pieces of the steganographic process as: cover_medium + hidden_data + stego_key = stego_medium. The main aim of using the steganography is to prevent detection of secret information from the unauthorized parties. 2. RELATED WORK The data hiding process for embedding the information into any digital content can be done by steganography techniques without causing perceptual. To hide data, the popular techniques used are watermarking, steganography and cryptography. In ancient Greek, research on steganography techniques has done. On that time a secret message tattooing on the shaved head of a messenger and before sending him to the destination letting his hair to grow back. The famous method used in around 400 B.C. is tradition steganography technique in which the document marked with invisible ink lie lemon juice. There are various techniques proposed for image steganography. The most popular technique which is the simplest and widest known steganography method is Least Significant bit, which replaces the least significant bit of pixels selected to hide the content that holds information. Complete discussion on LSB could be found in [1]. Further an improved LSB substitution method used by V. K. Sharma and V. Shrivastava in [3], where MSB of secret image in to LSB of cover image get embedded. A. Sharma, A. Agrawal and V Kumar introduced a technique [4], where large amount of data could be hidden in enciphered with the help of secret key,