How a VPN Works and Why You Should Care The best VPNs can make your online life more private with software that is convenient and cheap, sometimes even free. While keeping your IP address invisible, you can use your VPN to explore streaming content from all over the world or virtually sneak into a sports event that is not available in your area. However, while VPNs are widely available, there is a strange dearth of information on what they actually do behind the scenes. You may know that a VPN masks your device with a proxy server to make it look like you are somewhere else, and maybe even that encryption is involved. But the inner workings are not that difficult to understand, and knowing them helps you choose the right service. What is a VPN? A VPN, or virtual private network, is a method of securely accessing a network. Initially for organizations, they are now widely marketed to individuals. Broadly, a VPN has two parts: the server, which forwards your requests to the internet, and the client software on your device that you use to connect to it. What Happens When You Use a VPN? First, you use the client to connect to a server. Once connected, every internet request you make goes through that VPN server first. The communication between your device and the server is encrypted, so it cannot be traced back to you. The VPN server decrypts your request, sends it to the intended website, receives the response, encrypts it again, and sends it back to you. To the outside world, including your internet service provider, the online activity appears to come from the VPN server, not your device. What is the Point of Using a VPN? The two biggest reasons are maintaining greater anonymity and changing your virtual location. By masking your IP address, a VPN helps prevent your ISP from tracking and selling your browsing data. It can also protect activists or journalists. Changing your virtual location lets you access geo-restricted content, like different streaming service libraries, or bypass national firewalls. How Does a VPN Work? The Technical Explanation When you are not using a VPN, your internet traffic flows directly from your modem to your ISP and then to its destination. A VPN intervenes in this process. The process is often called tunneling. When you send data, your VPN client encrypts it and wraps it in an outer packet addressed to the VPN server. This creates an encrypted tunnel. Your ISP only sees encrypted data going to the VPN server. The server decrypts the inner packet, forwards your request to the real website, and then reverses the process to send the website’s response back to you securely. VPN Protocols and Encryption VPN protocols are the set of rules and technologies that handle this encryption and routing. Common protocols include OpenVPN and WireGuard. You will often hear about military-grade encryption, which typically refers to the AES-256 encryption standard. This is a strong symmetric cipher, meaning the same key is used to lock and unlock the data. However, using just a symmetric key is not fully secure for setting up the connection, as that key could be intercepted. Therefore, protocols like OpenVPN first use an asymmetric encryption handshake, like TLS, to establish a secure connection between your device and the VPN server. Once that secure channel is set up, they switch to faster symmetric encryption like AES-256 to handle the actual data transfer. This combination provides both security and speed. Putting It All Together Here is the simplified journey of your data with a VPN: You connect your client to a VPN server, establishing a secure tunnel. You visit a website. Your request is encrypted by the client and sent to the VPN server. The server decrypts it and forwards it to the website. The website sends data back to the VPN server. The server encrypts that data and sends it through the tunnel to your client, which decrypts it for your browser. You see the webpage, with your real IP address hidden. How to Use This Information Knowing how a VPN works helps you cut through marketing hype. Claims of military-grade encryption are standard, not unique. A VPN does not make you completely anonymous, especially if you log into personal accounts. It can help with some ISP throttling tied to your IP address, but not all slowdowns. A VPN is a powerful tool for privacy, but it is just one part of a complete cybersecurity practice, which should also include strong passwords, software updates, and general vigilance online.
