02-05-2013, 02:56 PM
A paper presentation on STEGANOGRAPHY
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ABSTRACT
Steganography (a rough Greek translation of the term Steganography is secret writing) has been used in various forms for 2500 years. Steganography is the art and science of hiding information by embedding messages within other, seemingly harmless messages. It has found use in variously in military, diplomatic, personal and intellectual property applications. Briefly stated, steganography is the term applied to any number of processes that will hide a message within an object, where the hidden message will not be apparent to an observer. This paper will explore steganography from its earliest instances through potential future application.
This paper introduces steganography by explaining what it is, providing a brief history with illustrations of some methods for implementing steganography. Though the forms are many, the focus of the software evaluation in this paper is on the use of images in steganography. We have even discussed various secret communication methods used, its comparison with Cryptography and Digital Watermarking. Finally, future projections on this perfect file encryption technique are made, along with few explanations using our own software and programs.
INTRODUCTION
Johannes Trithemius (1462-1516) was a German Abbot. His writing, “Steganographia: hoe est ars per occultam scripturam animi sui voluntatem absentibus aperiendi certa” is ostensibly a work describing methods to communicate with spirits. A rough translation of the Latin title is: “Steganography: the art through which writing is hidden requiring recovery by the minds of men.” Although people have hidden secrets in plain sight—now called steganography—throughout the ages, the recent growth in computational power and technology has propelled it to the forefront of todays
Security techniques.
What is Steganography:
Steganography literally means
Covered writing or hidden writing i.e., writing that is known
To casual observer, is derived from Greek words ‘steganos’
Meaning covered or secret and ‘graphy’ meaning writing or
Drawing. This technique includes all methods of secure and
Secret communication that conceal the existence of secret
message. From the time of Herodotus in Greece till today, Steganography has been used in various places. Today the field attains new dimensions with the advent of digital computer.
IMPLEMENTATION OF STEGANOGRAPHY
There are ways to hide information in an image, audio and even text files. Moreover, if that message is in addition encoded then it has one more supplemental level of protection. Computer steganography is based on two principles. The first one is that the files that contain digitized images or sound can be altered to a certain extend without loosing their functionality unlike other types of data that have to be exact in order to function properly, an example of that would be a computer program.
Text Techniques:
Hiding information is to conceal it in what seems to be inconspicuous text. It is more difficult when it comes to electronic versions of text. Copies are identical and it is impossible to tell if it is an original or a copied version. To embed information inside a document we can simply alter some of its characteristics. These can be either the text formatting or characteristics of the characters. The key to this problem is that we alter the document in a way that it is simply not visible to the human eye yet it is possible to decode it by computer. Figure shows the general principle in embedding hidden information inside a document.
LIMITATIONS
There are limitations on the use of steganography due to the size of the medium being used to hide the data. In order for steganography to be useful the message should be hidden without any major changes to the object it is being embedded in. This leaves limited room to embed a message without noticeably changing the original object. This is most obvious in compressed files where many of the obvious candidates for embedding data are lost. Detecting hidden data remains an active area of research. How do you protect against malicious Steganography?
Unfortunately, all of the methods mentioned above can also be used to hide illicit, unauthorized or unwanted activity. What can be done to prevent or detect issues with steganography? Other uses for steganography range from the trivial to the abhorrent, including Criminal communications, Fraud, Hacking, Electronic payments, Gambling, pornography.
ADVANTAGES
Attempting to detect the use of steganography is called Steganalysis (the task of detecting and possibly disabling steganographic information) and can be either passive, where the presence of the hidden data is detected, or active, where 3 work of breaking the code. Today, less painful but more cryptic methods could be used to hide information in publicly available web site images. The image is visibly indiscernible even to a trained eye. The only hope is to enlist science to see past the pixels, but is this possible?
CONCLUSION
Steganography is a dynamic tool with a long history and the capability to adapt to new levels of technology. It has its own place in computer data security. By the amount of free and commercial tools available today, one can deduce that the use of steganography is growing. Steganography is just another tool for ss will surely need to be aware of its existence as its use becomes more prevalent. Hiding a message with steganography methods reduces the chance of a message being detected. In and of itself, steganography is not a good solution to secrecy, but neither is simple substitution and short block permutation for encryption. But if these methods are combined, you have much stronger encryption routines. Like any tool, steganography is neither inherently good nor evil, it is the manner in which it is used which will determine whether it is a
benefit or a detriment to our society.