Limitations of the WEP Protocol

WEP is vulnerable because the relatively short IVs and keys remain static. Within a short amount of time, WEP eventually uses the same IV for different data packets. For a large busy network, the same IVs can be used within an hour or so. This results in the transmitted frames having key streams that are similar. If a hacker collects enough frames based on the same IV, the hacker can determine the shared values among them (the key stream or the shared secret key). This can allow to the hacker to decrypt any of the 802.11 frames.

A major underlying problem with the existing 802.11 standard is that the keys are cumbersome to change. The 802.11 standard does not provide any functions that support the exchange of keys between stations. To use different keys, an administrator must manually configure each access point and radio NIC with a new common key. If the WEP keys are not updated continuously, an unauthorized person with a sniffing tool can monitor your network and decode encrypted frames.

Despite the flaws, you should enable WEP as a minimum level of security. Many hackers are capable of detecting wireless LANs where WEP is not in use and then use a laptop to gain access to resources located on the associated network. By activating WEP, however, you can at least minimize this from happening. WEP does a good job of keeping most honest people out.