ZyXEL Communications G-470, User Manual

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G-470 User’s Guide
32 Chapter 3 Wireless LAN Network
• Every device in the same wireless network must use security compatible with the AP or
peer computer.
Security stops unauthorized devices from using the wireless network. It can also protect
the information that is sent in the wireless network.
3.2 Wireless LAN Security
Wireless LAN security is vital to your network to protect wireless communications.
If you do not enable any wireless security on your ZyXEL Device, the ZyXEL Device’s
wireless communications are accessible to any wireless networking device that is in the
coverage area. See
Section 6.4 on page 61 for more information on configuring wireless
security for your device.
3.2.1 User Authentication and Encryption
User authentication is when every user must log in to the wireless network before they can use
it. However, every wireless client in the wireless network has to support IEEE 802.1x to do
this.
Wireless networks can use encryption to protect the information that is sent in the wireless
network. Encryption is like a secret code. If you do not know the secret code, you cannot
understand the message.
3.2.1.1 Certificates
Your ZyXEL Device can use certificates (also called digital IDs) for user authentication.
Certificates are based on public-private key pairs. A certificate contains the certificate owner’s
identity and public key. Certificates provide a way to exchange public keys for use in
authentication.
A Certification Authority (CA) issues certificates and guarantees the identity of each
certificate owner. There are commercial certification authorities like CyberTrust or VeriSign
and government certification authorities.
In public-key encryption and decryption, each host has two keys. One key is public and can be
made openly available; the other key is private and must be kept secure. Public-key encryption
in general works as follows.
1 Tim wants to send a private message to Jenny. Tim generates a public key pair. What is
encrypted with one key can only be decrypted using the other.
2 Tim keeps the private key and makes the public key openly available.
3
Tim uses his private key to encrypt the message and sends it to Jenny.
4 Jenny receives the message and uses Tim’s public key to decrypt it.