Intel 2200BG, Руководство пользователя

Страница: 45 / 84

encryption. A network key can be provided for you automatically (for example, it might be
provided on your wireless network adapter, or enter it yourself and specify the key length
(64-bits or 128-bit), key format (ASCII characters or hexadecimal digits), and key index
(the location where a specific key is stored). The longer the key length, the more secure
the key. Every time the length of a key is increased by one bit, the number of possible
keys double. Under 802.11, a wireless station can be configured with up to four keys (the
key index values are 1, 2, 3, and 4). When an access point or a wireless station transmits
an encrypted message using a key that is stored in a specific key index, the transmitted
message indicates the key index that was used to encrypt the message body. The
receiving access point or wireless station can then retrieve the key that is stored at the
key index and use it to decode the encrypted message body.
Encryption Static and Dynamic Key Types
802.1x uses two types of encryption keys, static and dynamic. Static encryption keys are
changed manually and are more vulnerable. MD5 authentication only uses static
encryption keys. Dynamic encryption keys are renewed automatically on a periodic basis.
This makes the encryption key(s) more secure. To enable dynamic encryption keys, you
must use 802.1x certificate-based authentication methods, such as TLS or TTLS or
PEAP.
Encryption Overview
Security in the WLAN can be supplemented by enabling data encryption using WEP
(Wireless Encryption Protocol). You can choose a 64 or 128 bit level encryption. Also,
the data can then be encrypted with a key. Another parameter called the key index is
provides the option to create multiple keys for that profile. However, only one key can be
used at a time. You can also choose to password protect the profile to ensure privacy.
The pass phrase is used to generate a WEP key automatically. You have the option of
either using a pass phrase or entering a WEP key manually. Using 64-bit encryption, the
pass phrase is 5 characters long and you can choose to enter any arbitrary and easy to
remember phrase like Acme1 or enter 10 Hexadecimal numbers for the WEP key
corresponding to the network the user wants to connect to. For 128-bit encryption, the
pass phrase is 13 characters long or you can enter a 26 hexadecimal numbers for the
WEP key to get connected to the appropriate network.
Note: You must use the same encryption type, key index number, and WEP key as other
devices on your wireless network. Also, if 802.1x authentication is being used, WEP