Definition - What does Four-Way Handshake mean?
A four-way handshake is a type of network authentication protocol established by IEEE-802.11i that involves standards set up for the construction and use of wireless local area networks (WLANs). The four-way handshake provides a secure authentication strategy for data delivered through network architectures.
Techopedia explains Four-Way Handshake
The four-way handshake uses a pass key called Pairwise Master Key (PMK), and concatenation of various data items to set up the encryption of data. These include single-use items called ANonce and SNonce, as well as the Mac addresses of the two endpoints involved. The main processes of the four-way handshake are done to enable an access point to authenticate itself to the client, and to provide secure encryption. The PMK is generally not sent over the network, leaving this component unshared and thus strengthening the security of the process.
While there is some debate about the specific points of four-way handshake authentication, it is used to send messages between an access point and a client in a secure way. This complex setup allows for a more secure authentication process that matches the complexity and vulnerabilities of modern networks.