Opportunistically encrypt network transport

 Tcpcrypt offers opportunistic security for TCP network traffic. All
 traffic between two tcpcrypt-enabled peers will be encrypted to
 protect against passive monitoring. tcpcrypt also exposes a strong
 session identifier to tcpcrypt-aware clients and servers, which can
 be used as a hook for authentication.
 .
 This package contains the network daemon, which will accept and wrap
 traffic redirected to it.