What Is Four-Way Handshake?

How would you like to have a handy, high-tech handshake that can help you connect to a wireless network? It's called the "Four-Way Handshake," and it's one of the most important ways to protect yourself when using a public network. Here's how it works: When someone wants to connect to an open Wi-Fi network, they send out a probe request packet. This packet asks any nearby devices if they're on an available network. If the device that receives this packet is on an open web, it will send back an acknowledgment packet saying, "Yes, I am on an open network." Then, after receiving this acknowledgment, the first device will send out another probe request packet, requesting that the second device add itself and its MAC address (which is like a serial number for all devices connected to a network). The second device then sends back another acknowledgment packet saying, "Yes, I'm here too!" with its own MAC address attached. Finally, when both devices acknowledge each other and know they're connected to the same network, they can start talking about whatever data they want without worrying about anyone else getting in on the conversation! The four-way handshake is a fancy saying, "let's get to know each other." It's used to establish secure encryption between two devices. It uses a passkey, Pairwise Master Key (PMK) and concatenates various data items to set up data encryption. These include single-use things called ANonce and SNonce and the Mac addresses of the two endpoints involved. The main thing of the four-way handshake is to enable an access point to authenticate itself to the client and provide secure encryption. The PMK is generally not sent over the network, leaving this component unshared and thus strengthening the security of the process.