What is Open System Authentication (OSA)?
Open System Authentication (OSA) is a process by which a computer can gain access to a wireless network that uses the Wired Equivalent Privacy (WEP) protocol. With OSA, a computer equipped with a wireless modem can access any WEP network and receive files that are not encrypted.
For OSA to work, the service set identifier (SSID) of the computer should match the SSID of the wireless access point. The SSID is a sequence of characters that uniquely names a wireless local area network (WLAN). The process occurs in three steps. First, the computer sends a request for authentication to the access point. Then the access point generates an authentication code, usually at random, intended for use only during that session. Finally, the computer accepts the authentication code and becomes part of the network as long as the session continues and the computer remains within range of the original access point.
If it is necessary to exchange encrypted data between a WEP network access point and a wireless-equipped computer, a stronger authentication process called Shared Key Authentication (SKA) is required.