International Journal on Recent and Innovation Trends in Computing and Communication ISSN: 2321-8169 Volume: 2 Issue: 9 2862 - 2866 _______________________________________________________________________________________________ 2862 IJRITCC | September 2014, Available @ http://www.ijritcc.org _______________________________________________________________________________________ A Review on Edge Based Image Steganography Deepika Dongre Assistant Professor Department of Computer Science & Engineering Acropolis Technical Campus Indore, India deepikacs1912@gmail.com Rina Mishra Research Scholar Department of Computer Science & Engineering Patel College of Science & Technology Indore, India rinamishra.cse13@gmail.com Abstract-Security of the information has always been the interesting area for researchers. Integrity, Confidentiality, and Authentication are main security principles. There are so many techniques developed to achieve these security principles using cryptography. But all these techniques are unable to keep the communication secret. Although the attacker is unable to access the secret message but he knows about the existence of the message. To overcome this limitation of cryptography a new idea is proposed by researchers that is Steganography. Steganography is the art of concealing secret message in a carrier such as text, image, audio, video and protocol messages. Different Steganography techniques are used based on these carrier messages and way of hiding. The choice of these method is depends on the requirements of application. Some application requires huge data embedding and some require high secrecy. This paper gives a review on image Steganography based on edge detection and their comparative study. It also gives an overview of basic edge detection techniques. Keywords- PVD; LSB; Steganography; Integrity; Confidentiality; Authentication and Cryptography. __________________________________________________*****_________________________________________________ I. INTRODUCTION The rapid development of technology enables high-speed and economic communication worldwide. With innovation of technology security threats are also growing rapidly. Security is the vital requirement of a communication from international communication to personal communication. A technique which only secures the content of messages like cryptography increases the chances of compromising the security. But Steganography is the technique to hide the fact that communication is taking place. It is the best way to secure the communicating messages because if attacker is unaware about the communication the chances of attack are reduced automatically. A. Overview of Steganography: Steganography is the Greek word which is made up of two words “stegos” means covered and “grafia” means writing, so Steganography means covered writing [1]. Steganography enables secret communication between source and destination. The main aim of Steganography is to hide secret information in carrier medium in such a way that it looks like an original medium. Previously, various methods based on Steganography were used like wax tablet, invisible ink and shave heads and many similar techniques. In wax tablet, the secret message was written on wood and further covered with wax. In another technique, invisible ink was used to write the secret message which becomes visible only when paper got heated. Many times master used to shave his slave’s head wrote his secret message on his scalp. When slave’s hair grew up then he sent him to intended receiver. The receiver again shaved slave’s head and got the secret message. One more technique called Microdot was developed in Germany at the time of Second World War. The photographic information was reduced in size of typed period and it was embedded into cover image. The concept of Steganography can be understood with the help of Prisoner’s problem [3]. Two inmates hatch a plan to escape from prison. A warden is observing the secret communication. If the warden will come to know about the secret communication, he will throw in solitary confinement. That’s why they starts communicating in such a way that warden don’t know about their secret communication. They used to hide their messages into another carrier object to be unperceived. The terms used in Steganography are: stego image, cover image, secure message and stegonalysis. Secure message is the message which we want to keep secure. Cover image is the carrier image which contains hidden message. So the stego image is that cover image which is going to be transferred with a secret message. B. Types of Steganography: Steganography are of different types which depend on the type of carrier medium. The carrier medium of high redundancy is most preferable choice. The commonly used mediums are [1]:  Text Steganography: The secret message is hided in a text file which is transfer through open channel. The characters of secure message are embedded at specific character of each word or selected word. The Message hiding depends upon stego key.  Image Steganography: Image is the most popular cover object for Steganography due to its privileged redundancy. The minor changes in image pixel are unnoticeable to human visual system and this property is utilized in image Steganography.  Audio Steganography: It is similar to image Steganography with minor changes in audio carrier that is unnoticeable to human ear. It is not widely used due to large size of audio cover file as compare to text and image cover.