The WLAN Open System authentication as the name suggests does not perform any authentication of the WLAN station desirous of joining the network. The WLAN client device will send an 802.11 authentication request frame and the Access point will respond with an 802.11 authentication response frame with a success code (0x0).
The below packet captures depict an open system handshake.
- 802.11 Client sends an 802.11 Authentication frame with the authentication algorithm set to Open System
- Access Point responds to the 802.11 Authentication frame with a success code message set to successful and authentication sequence increased by 1
In a WLAN Open System Authentication, the WLAN station and the Access Point can still send encrypted data packets to one another if both the Access Point and the WLAN station share a pre-configured Encryption key