What is steganography?
Steganography [from Greek]: write under protection; write covered
Steganography is the art and science of hiding information.
The most well known technique of steganography is invisible ink. The information age yields completely new methods and very powerful techniques.
Steganos applies two completely different methods for hiding data inside files. Both methods alter neither the file's attributes nor their time stamps.
Hiding data inside graphic and sound files
Steganos uses the least significant bit of a data element to hide information within. A data element are 8 bit (1 bye) in a 8 bit file and 16 bit (2 byte) in a 16 bit file. For example Steganos uses the least significant bits in a 8 bit wave form file to hide data therein. These slight modifications can't be recognized by the human ear because of the background noise. So the data is actually hidden. In picture files pixel colors are slightly modified but not significant enough to annoy the human viewer.
Steganos does not hide data within the header of files.
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DyCeS (Dynamic Cell Spreading) DEMCOM developed the DyCeS algorithm which causes the modification of bits to be spread all over the file. This decreases the chance to detect (not decrypt) hidden data. The algorithm is specially designed for hiding data inside sound and picture files.
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Hiding data in text files
To hide data within text files Steganos adds tabs and spaces to the end of lines. Steganos hides one byte per text line (8 bit are represented as a combination of 8 tabulator characters and spaces). Compared to the technique of hiding data inside graphic and sound files this method can be easily detected. This method is not recommended of you have the choice.
Why combining cryptography and steganography
If "only" encryption is used to protect your data information is not readable to others. But it is obvious that you have a secret.
If you use "only" steganography your data is invisible. But simply by checking all possible files for hidden data it would be possible to restore hidden data.
Steganos combines these two powerful techniques. Data which is hidden and encrypted by Steganos is unlikely to be found and virtually impossible to be decrypted.
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