Datasheet

AP-5131 Introduction
1-7
or formula for scrambling the data. A key is the specific code used by the algorithm to encrypt or
decrypt the data. Decryption is the decoding and unscrambling of received encrypted data.
The same device, host computer or front-end processor, usually performs both encryption and
decryption. The data transmit or receive direction determines whether the encryption or decryption
function is performed. The device takes plain text, encrypts or scrambles the text typically by
mathematically combining the key with the plain text as instructed by the algorithm, then transmits
the data over the network. At the receiving end, another device takes the encrypted text and decrypts,
or unscrambles, the text revealing the original message. An unauthorized user can know the
algorithm, but cannot interpret the encrypted data without the appropriate key. Only the sender and
receiver of the transmitted data know the key.
Wired Equivalent Privacy (WEP) is an encryption security protocol specified in the IEEE Wireless
Fidelity (Wi-Fi) standard, 802.11b and supported by the AP-5131 AP. WEP encryption is designed to
provide a WLAN with a level of security and privacy comparable to that of a wired LAN. The level of
protection provided by WEP encryption is determined by the encryption key length and algorithm. An
encryption key is a string of case sensitive characters used to encrypt and decrypt data packets
transmitted between a mobile unit (MU) and the AP-5131. An AP-5131 and associated wireless
clients must use the same encryption key (typically 1 through 4) to interoperate. For additional
information on configuring WEP, see Configuring WEP Encryption on page 6-15.
1.1.8.4 KeyGuard Encryption
Use KeyGuard to shield the master encryption keys from being discovered through hacking. KeyGuard
negotiation takes place between the access point and MU upon association. The access point can
use KeyGuard with Symbol MUs. KeyGuard is only supported on Symbol MUs making it a Symbol
proprietary security mechanism. For additional information on configuring KeyGuard on the AP-5131,
see Configuring KeyGuard Encryption on page 6-17.
1.1.8.5 Wi-Fi Protected Access (WPA) Using TKIP Encryption
Wi-Fi Protected Access (WPA) is a security standard for systems operating with a Wi-Fi wireless
connection. WEP’s lack of user authentication mechanisms is addressed by WPA. Compared to WEP,
WPA provides superior data encryption and user authentication.
WPA addresses the weaknesses of WEP by including:
• a per-packet key mixing function
• a message integrity check
• an extended initialization vector with sequencing rules