He was paraded at the front of the news media, knowing very well that he will not be able to say anything critical about his captors. When he was put to speak, he passed message by blinking his eyes in Morse code which spelled out T-O-R-T-U-R-E.
In computers, images are array of numbers representing light intensities at various pixels or points. Digital pictures have either 8 bit or 24 bit per pixel. Each bit represents an association of palette or color index. In color image of the 8-bit, every pixel that points out to only one of the 256 colors is represented by a single byte (sellars). 0's and 1s are bits whereby 8 bits create a byte. An example, of a byte is the 111 11110. The less significant bit is the position where zero is located. The least Significant bit (LSB) way is the staganography technique that is mostly implemented. When applying techniques of LSB to every byte of a 24-bit image, there are three bits of LSB that can be encoded to every pixel. Any variations in the LSB produce images which can not be distinguished from the original. This kind of technique may work well in 24-bit images but poorly in 8 bit images. (Johnson, 2001)
Modern steganography involves the use of computer technology to actively and passively code, convey and subsequently decode the steganographic message. The computer by itself identifies a picture in terms of very tiny picture elements. The picture elements are usually described in terms of various bits. The digital picture format is composed of either 24 bits or 8 bits per pixel. The individual bits are however linked to particular color index.
A perfects example is that in an 8-bit color digital imagery, one of the 256 colors per pixel is denoted as a single byte (Sellars).The 24-bit color imagery also has its own schema. The various bytes that represent the colors can be manipulated to contain certain hidden information. This is done by using one picture to hide a certain message file inside another file. The file which contains the hidden message is referred to as the "container file." The container file is taken through a very manipulative and yet non-destructive process which leaves the original message intact and undetectable by the human eye and ear. The paradox that surrounds the use of this technology is that its original use was targeted towards the prevention of the illegal distribution of sensitive documents electronically. This could have resulted in the various copyright infringers gaining access to the documents without duly paying the original owner of the document (Sellars).
In the past few years, more complex methods of steganography have been devised. These new methods are built with the intention of beating or rather evading detection by the common or rather standard detection techniques. The modern methods include the analysis of the image to be used prior to embedding the information on it. This is in order to determine its statistical properties. The redundant bits of the image are then located and then they get replaced probabilistically with new but redundant information bits. This method helps in beating the common statistical steganographic analyzers. The image is then subsequently modified in certain parts. This makes it very hard to recreate the original statistical footprints of the image.
The previous introductions of various encoding software have made it absolutely easy for anyone to compose a steganographic message. Most of the steganographic tools are also available online as freeware and therefore easily downloadable over the internet. Examples include the "StegFS" which is windows based. The steganograhic tool hide the information in the imagery. The various steganographic tools therefore are developed and then subsequently released in order to detect the existence of steganographic content. An image suspected to contain hidden information is then ran through the software which initiates a dictionary attack on the suspect image in order to determine the various key phrases.
Detection of Steganography
It is very important for various governments and corporations to devise effective and efficient methods of detecting the existence of covertly stored information within the various imagery that are being transmitted across their national borders, be it electronically or otherwise. This is because steganography can be a major source of national insecurity as it may aid rebels and terrorists in easily communicating right under the noses of the authorities.
The recent involvement of the U.S. authorities with Iomart, a Scottish corporate spyware vendor in an effort of tracking down Osama Bin Laden has shed some light into the possible detection of steganographic messages.The firm leaked certain information regarding the use of Key fingerprint = AF19 FA27 2F94 998D FDB5 DE3D F8B5 06E4 A169 4E46
In detecting and identifying several files some of which had Arabic text and dates.
The commissioning of WetStone Technologies by the United States Air Force in order to come up with a set of accurate statistical tests with the ability to detect and isolate secret messages stored or transmitted in computer is one of the major steps that have ever been taken in oerder to combat terrorism communication through steganographs.The firm was also commisiioned to effectively come up and identify the core underlying principles that fueld the steganographic techniques (McCullagh).Their finding a however pointed out categorically that most of the steganography that they discovered were traceable to hacker sites and many more on the high traffic e=-commerce websites such as e-bay and Amazon.com (McCullagh).Other steganographic have been developed and others are under development.An example of a stego-detector is the "Steganography Detection and Recovery Toolkit" (S-DART) which was designed by the WetStone Technologies.
Even though there is lack of concrete exhibit in the form of a stegnographic image to support the alleged use of steganography by terrorists to pass their messages through the internet; it is quite imaginable to idealize the fact that the technology can actually be employed in the process of passing secret messages between various terrorist cells. The fact that various steganographic tools are readily available to create these messages is even more worrying. The technology involved in steganography has in actual fact been upgraded to a point that it is almost impossible to detect its presence on any images.
The utilization of various scanners such as the fingerprint* product has seen the normal workplace placed under the watchful eye of the steganography detection technology. This is in an effort to rid the corporate networks by unmasking the employees who maybe secretly passing out very sensitive information for the purpose of implementing various terrorist intensions.
The role of United States law is evident from the fact that its legislative wing has enacted various legislations as a reaction to the perceived threat that can be caused through the use of steganography.The passed legislation would allow the U.S. government to embark on projects that would result in the coming up with appropriate technologies geared towards the detection of the encoded imagery that is based on the suspected threat. This enactment is fully put into action through the "USA Patriot Act" which got signed in 2006.The Act gives the federal government the powers to monitor all forms of electronic communication that might be emanating from various terrorist groups. In order to illustrate the gravity of the perceived threat that could arise from the use of steganographic images, the United States legislature passed the electronic communication aspect of the act even before substantial evidence was gathered to prove that terrorist really use apply the technology while communicating with each other, both within and without the United States of America.
The idea of having a perfectly secure internet is still a dream. This is despite the fact that various research and studies have been dedicated to the field of internet security. The ever evolving nature of internet threats is however a major blow to the ongoing efforts to the internet security problem. As for now the concept of terrorist applying steganography in their communications is a myth. It is however very possible to predict the kind of reaction and level of preparedness that would result if an actual steganographic imagery with credible details such as the intended target is found with the terrorists. At this moment, therefore, the concept of terrorist using steganography to covertly communicate with each other remain a total myth that will be proved maybe with time.
B.W. Lampson, (1973), a note on the confinement problem, Communications of the ACM, vol.16, no. 10, pp. 613 -- 615.
Declan, McCullagh. (2001) Bin Laden: Steganography Master?