Steganography

Steganography is a technique of hiding data (the secret message) in some other data in such a way that no one apart from the intended recipient knows of the existence of the secret message. One well-know example is hiding a message in the (lower color bits) of an image. This webpage demonstrates how to hide short textual message into a large one.

The advantage of steganography is that message does not attract attention. An unhidden coded message, no matter how unbreakable it is, will arouse suspicion.

Terminology

• covertext In steganography, the message will appear to be something else: a picture, a song, a text, or something else. This apparent message is known as the covertext; it is only the carrier for the real message.
• plaintext The covertext is modified in some way to contain the secret message, which is known as the plaintext.
• stegotext The modified covertext, with the plaintext woven in, is known as the stegotext.

Manual

Choose the tab Encrypt to enter a plaintext and a covertext and then press the 'encrypt' button. If the covertext is large enough to hide the plaintext in, the plaintext is woven into the covertext to generate the stegotext.

Choose the tab Decrypt to enter a stegotext (by default, it has the stegotext generated on the Encrypt tab). Press the 'decrypt' button, and the plaintext is extracted.

Some quick ways to start:

• Choose tab 'Encrypt' and press 'Demo2a', then 'Demo2b', then 'Demo2c'.
  Watch how the stegotext (bottom text area) changes with the plaintext (top text area).
• Choose tab 'Encrypt' and press 'Demo1', then choose tab 'Decrypt' and press 'Decrypt'.
  See how the plaintext is encrypted and decrypted.

Links

• Wikipedia
• An article

Plaintext:	Type your plaintext (short!) here
Covertext:	Type your covertext (long!) here
Stegotext:	Your stegotext will appear here - when you press 'encrypt'

Stegotext:	Enter your stegotext here (or press 'Copy')
Plaintext:	Your plaintext will appear here - when you press 'decrypt'