Hidden Messages in JPEG Image Using Steganography

Steganography is the process of hiding one medium of communication (text, sound or image) within another. In the last few years, we have seen many new and powerful steganography and steganalysis techniques reported in the literature. The modern Methods of Steganography use the properties of the media itself to convey a message. Digitally embedding messages in other media, such as: Plain Text, Hypertext, Audio / Video, Still Imagery, Network Traffic. In the following tutorial we go over some general concepts and ideas that apply to image steganography and steganalysis. We review and discuss the notions of steganographic security and capacity. The goal of Hidden Messages in JPEG Image Using Steganography. 137 this paper is to determine the steganographic capacity of JPEG images by using DCT coefficients properties and static analysis for them. We illustrate also some techniques for image Steganography. Introduction Steganography is the art and science of hiding communication; a steganographic system thus embeds hidden content in unremarkable cover media so as not to arouse an eavesdropper’s suspicion. In the past, people used hidden tattoos or invisible ink to convey steganographic content. Today, computer and network technologies provide easy-to-use communication channels for steganography.[2][5] The word Steganography comes from the Greek steganos (covered or secret) and graphy (writing or drawing) and means, literally, covered writing. We will look at history of Steganography through to current day uses and advancements in the area, explaining how the digital age has seen the possible rebirth of Steganography and Steganlysis, the process of finding the hidden information.[4][8] The goal of Steganography is to avoid drawing suspicion to the transmission of a hidden message. If suspicion is raised, then this goal is defeated.[7] History of Steganography The first recorded use of Steganography is from the Histories of Herodotus, where in ancient Greece text was written on wax covered tablets. Herodotus describes how Demeratus wanted to warn Sparta on an imminent invasion from Xerxes. In order to hide the message he scraped wax off a tablet and wrote a message. The tablet was then covered with wax again. Upon inspection by enemy soldier the tablets appeared blank and were allowed to pass. Other ancient methods include tattooing messages on a courier’s head, and allowing their hair to grow, thus hiding the message and allowing the courier to deliver their message unhindered (although obviously their hair had to be removed again upon deliverance). [5] From the medieval period through to the renaissance many complex ciphers were being developed and used so also was Steganography. By the 1940’s Steganography was called upon again to hide secret messages. World War Two is better known for the birth of hardcore encoding (E.g. the German Enigma) and the computer to crack this code. Other forms include Great Britain’s S.O.E. (Special Operations Executive) passing messages to agents in occupied Europe written in invisible inks, these messages could appear as simple blank pieces of paper or another letter upon inspection but could contain vital Mafaz Mohsin Khalil & Sadoon Hussin Abdullha 138 communication written between the lines, only made visible in a given solution.[5][8]