Connectivity and Data Protection
solid authentication and encryption mechanisms in place, a company
runs a significantly high risk of information security attacks.
Wired Equivalent Privacy (WEP)
The 802.11 standard defines an optional WEP security mechanism,
which makes use of a secret shared key that alters the frame body of
data and management frames to avoid disclosure to eavesdroppers.
This process is also known as symmetric encryption: the keys must
match at both the source and destination station (or access point).
Figure 3.8 illustrates the WEP encryption process.
FIGURE 3.8
WEP Encryption Process
The WEP encryption process occurs as follows.
1.
At the sending station, the WEP process first runs the plaintext
through an integrity algorithm. This algorithm generates a
four-octet integrity check value (ICV) that is sent with the data
and checked at the receiving station to guard against
unauthorized data modification en route.
2.
The WEP process inputs the secret shared encryption key into a
pseudo-random number generator (PRNG) to create a key
sequence with length equal to the plaintext and ICV. The
process uses a 24-bit initialization vector (IV) as part of the
encryption key. The IV is sent unencrypted as part of the data
frame payload.
