+Security Improvements
+'''''''''''''''''''''
+
+- Newly generated introducer FURLs are unguessable. This helps to control
+ membership of private grids (although it does not stop someone who knows
+ the introducer FURL from providing any number of servers). The FURL is
+ stored in ``BASEDIR/private/introducer.furl`` rather than
+ ``BASEDIR/introducer.furl`` as before. To force an introducer to generate
+ a new FURL, delete the existing ``introducer.furl`` file and restart it.
+ After doing this, the ``[client]introducer.furl`` setting of every client
+ and server that should connect to that introducer must be updated. (`#1802`_)
+- The Welcome page no longer reveals the secret part (swissnum) of the
+ introducer and helper FURLs. For existing guessable introducer FURLs,
+ the ``introducer`` swissnum is still displayed to show that a guessable
+ FURL is in use. (`#860`_)
+