The virtual private network daemon vpnd is a daemon which connects two networks
on network level either via TCP/IP or a (virtual) leased line attached to a
serial interface. All data transfered between the two networks are encrypted
using the unpatented free Blowfish encryption algorithm.

vpnd is not intended as a replacement of existing secured communications
software like ssh or tunneling facilities of the operating system. It is,
however, intended as a means of securing transparent network interconnection
across potentially insecure channels.

WWW: http://sunsite.dk/vpnd/