Re: IPSec, VPN and PKI

[Rick Hale <optik_(_at_)_wccnet_(_dot_)_org>]

> Is there any relations between theses three concepts ?
> I mean: is one of them a pre-requesite to understand the other ?

A Virtual Private Network is used for establishing connections between
remote hosts. Note I did not say "secure connections." VPNs _by
themselves_ do not offer much security in the way of confidentiality or
integrity. In order to achieve this, one should use IPSEC (also note that
PPTP, L2TP, or SSH protocols may also be used in a VPN).

IPSEC has two modes, tunneling and transport. Transport is nice if you
want to, say  transfer data across a LAN. In transport mode, only the
_payload_ is encapsulated. For more distant connections, it's nice to
have your _entire_ packet encapsulated (both the data portion and the
header); this is where you'd use tunneling.

As for PKIs; i'll refer you to - http://www.pki-page.org/
which has some good info.


i hope this helps

rik
http://orchard.wccnet.org/~optik