NETGEAR 2.4 GHz MA111 Authentication and WEP Encryption, Example of Hexadecimal, Key Content

Authentication and WEP Encryption

The absence of a physical connection between nodes makes the wireless links vulnerable to information theft. To provide a certain level of security, IEEE 802.11 standard has defined two types of authentication methods, Open System and Shared Key. Open System authentication is a null algorithm. Shared Key authentication is an algorithm where both the transmitting node and the receiving node share an authentication key to perform a checksum on the original message. By default, IEEE 802.11 wireless devices operate in an open system network.

Wired Equivalent Privacy (WEP) data encryption is utilized when the wireless nodes or access points are configured to operate in Shared Key authentication mode. There are three shared key methods implemented in NETGEAR 802.11b solutions: the standard based 64-bit WEP data encryption and 128-bit WEP data encryption.

The 64-bit WEP data encryption method allows for a five-character (40 bits) input. Additionally, 24 factory-set bits are added to the 40-bit input to generate a 64-bit encryption key. (The 24 factory-set bits are not user configurable.) This encryption key will be used to encrypt/decrypt all data transmitted via the wireless interface. Some vendors may refer to the 64-bit WEP data encryption as 40-bit WEP data encryption since the user configurable key used in the encryption process is only 40 bits wide.

The 128-bit WEP data encryption method consists of 104 configurable bits. Similar to the 64-bit WEP data encryption method, the remaining 24 bits are factory set and not user configurable.

Encryption	# of Hexadecimal	Example of Hexadecimal
Key Size	Digits	Key Content
64-bits (24+40)	10	4C72F08AE1
128-bit (24+104)	26	4C72F08AE19D57A3FF6B260037

Wireless Channel Selection

802.11b

IEEE 802.11b wireless nodes communicate with each other using radio frequency signals in the ISM (Industrial, Scientific, and Medical) band between 2.4 GHz and 2.5 GHz. Neighboring channels are 5 MHz apart. However, due to spread spectrum effect of the signals, a node sending signals using a particular channel will utilize frequency spectrum 12.5 MHz above and below the center channel frequency. As a result, two separate wireless networks using neighboring channels (for example, channel 1 and channel 2) in the same general vicinity will interfere with each other.

Applying two channels that allow the maximum channel separation will decrease the amount of channel cross talk, and provide a noticeable performance increase over networks with minimal channel separation.

		Channel	Center Frequency		Frequency Spread
1	2412 MHz	2399.5	MHz – 2424.5 MHz
2		2417 MHz	2404.5		MHz –2429.5 MHz
		3		2422 MHz						2409.5	MHz –2434.5 MHz
4		2427 MHz						2414.5 MHz –2439.5 MHz
5			2432 MHz	2419.5				MHz – 2444.5 MHz
		6		2437 MHz				2424.5			MHz –2449.5 MHz
7		2442 MHz	2429.5			MHz –2454.5 MHz
8			2447 MHz	2434.5				MHz – 2459.5 MHz
9		2452 MHz	2439.5			MHz –2464.5 MHz
10		2457 MHz	2444.5			MHz –2469.5 MHz
11			2462 MHz	2449.5				MHz – 2474.5 MHz
12		2467 MHz	2454.5			MHz – 2479.5 MHz
13				2472 MHz	2459.5					MHz – 2484.5 MHz

Note: The available channels supported by the wireless products in various countries are different. For example, Channels 1 to 11 are supported in the U.S. and Canada, and Channels 1 to 13 are supported in Europe and Australia.

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