18-09-2017, 01:11 PM
Steganography is the practice of hiding a file, message, image or video within another file, message, image or video. The word steganography combines the Greek words steganos (στεγανός), meaning "covered, hidden or protected", and graphein (γράφειν) meaning "writing".
The first recorded use of the term was in 1499 by Johannes Trithemius in his Steganographia, a treatise on cryptography and steganography, disguised as a book on magic. Generally, hidden messages seem to be (or are part of) something else: pictures, articles, shopping lists, or some other cover story. For example, the hidden message may be in invisible ink between the visible lines of a private letter. Some steganography implementations lacking a shared secret are forms of security through obscurity, and key-dependent steganographic schemes adhere to the Kerckhoff principle.
The advantage of steganography over cryptography alone is that the intended secret message does not attract attention to itself as an object of scrutiny. Clearly visible encrypted messages, no matter how incredible, arouse interest and can be incriminating in countries where encryption is illegal.
While cryptography is the practice of protecting the content of a message alone, steganography is concerned with hiding the fact that a secret message is being sent as well as hiding the message content.
Steganography includes concealment of information within computer files. In digital steganography, electronic communications may include steganographic encoding within a transport layer, such as a document file, image file, program, or protocol. Media files are ideal for steganography transmission because of its large size. For example, a sender can begin with a harmless image file and adjust the colour of each hundredth pixel to match a letter of the alphabet. The change is so subtle that someone who is not specifically looking for it is unlikely to notice the change.
The advantage of steganography over cryptography alone is that the intended secret message does not attract attention to itself as an object of scrutiny. Clearly visible encrypted messages, no matter how incredible, arouse interest and can be incriminating in countries where encryption is illegal.
While cryptography is the practice of protecting the content of a message alone, steganography is concerned with hiding the fact that a secret message is being sent as well as hiding the message content.
Steganography includes concealment of information within computer files. In digital steganography, electronic communications may include steganographic encoding within a transport layer, such as a document file, image file, program, or protocol. Media files are ideal for steganography transmission because of its large size. For example, a sender can begin with a harmless image file and adjust the colour of each hundredth pixel to match a letter of the alphabet. The change is so subtle that someone who is not specifically looking for it is unlikely to notice the change.