Hiding and finding hidden Message In Media

Hiding and finding hidden messages behind media files.

Steganography is a very interesting process by which encoding of hidden messages in such a way is did so that , apart from the sender and recipient,none will know the existence of the message. In such a case stegano-graphic coding is used inside of a transport layer, such as a document file, image file, program or protocol.
Media files are ideal for steganographic transmission because of their large size. The process involves hiding some sort of image inside an image or a secret text inside image file,which is hard to detect without judging the pixels minutely.This is carried out by various ways and with help of some softwares.

Digital Text Unicode steganography uses lookalike characters of the usual ASCII set to look normal, while really carrying extra bits of information. If the text is displayed correctly, there should be no visual difference from ordinary text. Some systems, however, may display the fonts differently, and the extra information would be easily spotted.

Counter measures and detection

Detection of physical steganography requires minute physical examination, it is a time-consuming process with obvious resource use ,detection of steganographically encoded packages is called steganalysis. 

The simplest method to detect modified files, however, is to compare them to known originals. For example, to detect steganoprahic images, we need to compare the suspicious file along with the original (if available) and compare the bits in both formats. Its an must know for working and wannabe cyber crime experts as this knowledge is highly needed to decipher and decode hidden messages used by criminals in order to foil their devious plans and tactics.

This technology is such that it can be used in both good and malicious ways. Terrorists use this method to devise and communicate evil plans but even it can be used in benefiting ways also such as communcating group works and sensitive documentaion works also in office, such as to prevent data leakage or theft of data, in short the possibilities are many.

Below is a popular image showing how a steganographic image of a cat is extracted from that of a image of a tree.

SOURCE BLOG