ZyXEL Communications B-1000 6.2.2 Authentication, Auto, Shared Key, Open System, Shared Key Authentication, Open System Authentication, Figure 6-2WEP Authentication Steps

ZyAIR Access Point Series User’s Guide

6.2.2 Authentication

Three different methods can be used to authenticate wireless stations to the network: Open System, Shared Key, and Auto. The following figure illustrates the steps involved.

Wireless Station Authentication Access Point

Open System Authentication

Open System Request

Authentication Acceptance

Shared Key Authentication

Shared Key Request

Challenge Text

Encrypted Challenge Text

Authentication Acceptance

Figure 6-2 WEP Authentication Steps

Open system authentication involves an unencrypted two-message procedure. A wireless station sends an open system authentication request to the AP, which will then automatically accept and connect the wireless station to the network. In effect, open system is not authentication at all as any station can gain access to the network.

Shared key authentication involves a four-message procedure. A wireless station sends a shared key authentication request to the AP, which will then reply with a challenge text message. The wireless station must then use the AP’s default WEP key to encrypt the challenge text and return it to the AP, which attempts to decrypt the message using the AP’s default WEP key. If the decrypted message matches the challenge text, the wireless station is authenticated.

6-2 Wireless Security