Sidewinder G2 6.1.1 Administration Guide - Glossary of Technical ...

Protecting your
information
What are encryption and
authentication?
Sidewinder G2 VPN overview
Sending information beyond your Sidewinder G2 via the Internet is
like sending an unsealed envelope of important information via a
courier service: you must trust that the courier will not read or steal
the information.
To address this danger, an organization known as IETF (Internet
Engineering Task Force) developed a standard for protecting data on
unprotected (or untrusted) networks such as the Internet. The
standard has become known as IPSec, meaning Internet-Protocol
Security. In brief, IPSec calls for encrypting the data before it leaves
the local host, then decrypting it (removing its “cloak” of encryption)
when it is received at the destination or remote host. Once it is
decrypted, the data assumes its original form and can be read as
intended. No matter how long or circuitous its route through the
Internet, the data remains private by virtue of its encryption.
The two main components of IPSec security are encryption and
authentication.
Encryption — Encryption is the means by which plain text is
“cloaked.” It ensures that the transmitted data remains private and
unreadable until properly decrypted. The Sidewinder G2 uses an
encryption key to encipher and decipher each unit of data sent
between your site and the “partner” or remote VPN site. (See
“About IPSec keys” on page 13-4.)
Authentication — VPN authentication prevents unauthorized
individuals from tampering with the contents of the data being
transmitted. It also prevents them from creating messages that
claim to come from a particular place but are actually sent from
somewhere else (such as the hacker’s home computer).
Authentication is accomplished through two methods:
— Data-integrity checking, which allows the receiver to verify
whether the data was modified or corrupted during transmission.
— Sender identification, which allows the receiver to verify
whether the data transmission originated from the source that
claims to have sent it.
Configuring Virtual Private Networks 13-3