Update docs.

README.rst

@@ -9,7 +9,7 @@ Passphrases to remember...
 .. _build-status: https://travis-ci.org/ulif/diceware
 
 
-`diceware` is a password generator following the proposals of
+`diceware` is a passphrase generator following the proposals of
 Arnold G. Reinhold on http://diceware.com . It generates passphrases
 by concatenating words randomly picked from wordlists. For instance::
 
@@ -17,7 +17,7 @@ by concatenating words randomly picked from wordlists. For instance::
   Art83LiarRivetBlytheIs>am
 
 The passphrase contains by default six capitalized words with no space
-char or similar in-between and a single special char (the ``>`` in the
+char or similar in-between and a single special char (the ``">"`` in the
 example above).
 
 .. contents::
@@ -33,8 +33,8 @@ This Python package can be installed via pip_::
 The exact way depends on your operating system.
 
 
-How to Use
-----------
+Usage
+-----
 
 Once installed, use ``--help`` to list all available options::
 
@@ -118,6 +118,24 @@ entropy). Therefore you might think again about using special chars in
 your passphrase.
 
 
+Is it secure?
+-------------
+
+The security level provided by Diceware_ depends heavily on your
+source of random. If the delivered randomness is good, then your
+passphrases will be very strong. If instead someone can foresee the
+numbers generated by a random number generator, your passphrases will
+be surprisingly weak.
+
+This Python implementation uses the `random.SystemRandom`_ source
+provided by Python. On Un*x systems it accesses `/dev/urandom`. You
+might want to follow reports about manipulated random number
+generators in operating systems closely.
+
+The Python API of this package allows usage of other sources of
+randomness when generating passphrases.
+
+
 Credits
 -------
 
@@ -127,7 +145,7 @@ Arnold G. Reinhold deserves all merits for the working parts of
 Links
 -----
 
-- Diceware_ home page
+- The Diceware_ home page. Reading definitely recommended!
 - `Fork me on github`_
 
 Wordlists:
@@ -149,3 +167,4 @@ Copyright by Arnold G. Reinhold. See file LICENSE for details.
 .. _`Diceware8k list`: http://world.std.com/~reinhold/diceware8k.txt
 .. _`Diceware`: http://diceware.com/
 .. _`Fork me on github`: http://github.com/ulif/diceware/
+.. _`random.SystemRandom`: https://docs.python.org/3.4/library/random.html#random.SystemRandom