Hackers and terrorists have been using this form of technology for years. The United States governmental officials had suspected an attack on the United States for a period of time and thought the information to be hidden using steganography. Anyone can use and get access to steganographic materials. It's easy to download on numerous sights and no software is required. It's an easy and cheap way to keep information secure and undetectable. The number of steganography sites has doubled in the past two years (Kolata, F4). The United States government is also trying to place restrictions on encryption methods to prevent another catastrophic attack in the world such as the World Trade Center attacks. By having access to a private key the government would have unlimited access to secure information and crack codes all for safety reasons (USA Today). A " private key" is needed to decode any steganographic messages. Images are made up from a combination of an abundant of pixels (tiny dots). Steganographers use these pixels within the same color scheme as the hidden image to send messages. Steganography messages can be next to impossible to spot without the concept of Steganalysis. Steganalysis combs through images looking for alterations in data patterns. Where to look is the key problem though. A plan to launch bombs could be hidden in the petals of a flower (Kolata, F4) and be completely unnoticeable to the naked eye. One of the problems with Steganalysis is that it looks for alterations in data patterns. One of the most popular formats for images is JPEG (Kolata, F4), which is naturally distorted. This makes it even harder to detect hidden messages. How do you detect altered data patterns in an image format that is naturally distorted?
Steganography is the process of hiding one file inside another such that others can neither identify the meaning of the embedded object, nor even recognize its existence. Current trends favor using digital image files as the cover file to hide another digital file that contains the secret message or information. Steganography become more important as more people join the cyberspace revolution. Steganography is the art of concealing information in ways that prevent the detection of hidden messages. The goal of steganography is to avoid drawing suspicion to the existence of a hidden message. This approach of information hiding technique has recently become important in a number of application areas. Digital audio, video, and pictures are increasingly furnished with distinguishing but imperceptible marks, which may contain a hidden copyright notice or serial number or even help to prevent unauthorized copying directly. Military communications system make increasing use of traffic security technique which, rather than merely concealing the content of a message using encryption, seek to conceal its sender, its receiver or its very existence. Similar techniques are used in some mobile phone systems and schemes proposed for digital elections. One of the most common methods of implementation is Least Significant Bit Insertion, in which the least significant bit of every byte is altered to form the bit-string representing the embedded file. Altering the LSB will only cause minor changes in color, and thus is usually not noticeable to the human eye. While this technique works well for 24-bit color image files, steganography has not been as successful when using an jpeg color image file, due to limitations in color variations and the use of a color map. The advantages of LSB are its simplicity to embed the bits of the message directly into the LSB plane of coverimage and many techniques use these methods . Modulating the LSB does not result in a humanperceptible difference because the amplitude of the change is small. Therefore, to the human eye, the resulting stego-image will look identical to the cover-image. This allows high perceptual transparency of LSB. Another level of security adds to steganography by using an encryption technique for encrypting message before adding to image.
Data Hiding by Steganography Sample Thesis - DOC by nya22076
For a definition of Steganography I will quote Bryan Clair since he has defined it very elegantly:
Steganography is the dark cousin of cryptography, the use of codes. While cryptography provides privacy, steganography is intended to provide secrecy. Privacy is what you need when you use your credit card on the Internet -- you don't want your number revealed to the public. For this, you use cryptography, and send a coded pile of gibberish that only the web site can decipher. Though your code may be unbreakable, any
hacker can look and see you've sent a message. For true secrecy, you don't want anyone to know you're sending a message at all.
To achieve this secrecy, the process of steganography hides data within an image, sound file, movie, for example, so that its existence is hidden from prying eyes