Updated documentation (index.rst).

docs/index.rst

@@ -6,11 +6,39 @@
 Welcome to Stéganô's documentation!
 ===================================
 
-Contents:
-
 .. toctree::
    :maxdepth: 2
 
+Stéganô is a Python Steganography module.
+Steganography is the art and science of writing hidden messages in such a way that no one,
+apart from the sender and intended recipient, suspects the existence of the message, a form
+of security through obscurity. Consequently, functions provided by Stéganô only hide message,
+without encryption. Indeed steganography is often used with cryptography.
+
+The advantage of steganography, over cryptography alone, is that messages do not attract
+attention to themselves. If you are interested in cryptography have a look at my project pySecret.
+
+Requirements
+============
+
+- Python (2.4 -> 2.7);
+- Python Imaging Library (PIL).
+
+Methods of hiding
+=================
+
+For the moment, Stéganô implements these methods of hiding:
+
+- using the red portion of a pixel to hide ASCII messages;
+- using the Least Significant Bit (LSB) technique;
+- using the LSB technique with sets based on generators (Sieve for Eratosthenes, Fermat, Mersenne numbers, etc.);
+- using the description field of the image (JPEG).
+
+Moreover some methods of steganalysis are provided:
+
+- steganalysis of LSB encoding in color images;
+- statistical steganalysis. 
+
 
 
 Indices and tables