The basic idea of IPSEC is to provide security functions
(authentication and encryption) at the IP (Internet Protocol)
level. It will be required in IP version 6 (better known as IPng,
the next generation) and is optional for the current IP, version 4.

Openswan is an Open Source implementation of IPsec for the Linux
operating system. Is it a code fork of the FreeS/WAN project, started
by a few of the developers who were growing frustrated with the
politics surrounding the FreeS/WAN project.

New features that aren't tested as well as the main package
land here first. Then we beg the developers to accept the patches
until they get in (or so we hope!)

Currently, Openswan includes the follow major patches:

   * X.509 Digital Certificates
   * RFC 2409 Port Selectors
   * ALG 0.8.1 (All ciphers/hashes enabled as modules, inc 1DES)
   * Notify/Delete SA
   * NAT Traversal
   * Dead Peer Detection (DPD IETF Draft)

FreeS/WAN is a freely-distributable implementation of IPSEC protocol.

• Maxim Tyurin
• Michael Shigorin
• Anton D. Kachalov
• Dmitry V. Levin

• openswan
• openswan-libdes