Much of 802.11 growth can be attributed to the Wireless Ethernet Compatibility Alliance (WECA), which developed an interoperability standard called Wi-Fi (wireless fidelity).  Products bearing the Wi-Fi logo have passed a suite of basic interoperability tests that ensure they work with all other Wi-Fi–certified products.  The original WECA security standard was WEP (Wired Equivalent Privacy) which proved to be inadequate.  Since WEP is based on static keys (which don't change over time), wireless crackers can find the data needed to crack the key in seconds.

Many people assume that 802.11 signals travel only a relatively short distance —300 feet or so. The signals actually travel much farther but are too weak for the tiny antennas in the adapters to detect.  A high gain external antenna can detect 802.11 signals at a much greater distance.  This enables wireless crackers to access a wireless network at a distance of several hundred feet or more (such as a parking lot adjacent to a building), giving crackers adequate time to break weak security.

Wi-Fi Protected Access (WPA) is designed cure the deficiencies of older security for large and small businesses or home users.  Homes and small businesses use the Pre-Shared Key (PSK) mode of operation by entering a password (also called a master key) into their access point or wireless gateway and each PC on the wireless network.  WPA keeps out eavesdroppers and other unauthorized users by requiring all devices to have the matching password.  Temporal Key Integrity Protocol (TKIP) encryption is used for transmitting the password.  TKIP regularly changes the encrypted keys so that the same encryption is never used twice. This all happens automatically in the background, invisible to the user.