What protocol does VPN typically use to secure communications?

VPNs, or Virtual Private Networks, typically utilize SSL/TLS protocols to secure communications. SSL (Secure Sockets Layer) and its successor TLS (Transport Layer Security) are cryptographic protocols designed to provide secure communication over a computer network. When VPNs employ SSL/TLS, they authenticate the parties involved and encrypt the data being transmitted, ensuring that it remains confidential and protected from eavesdropping or tampering.

This approach is particularly popular in remote access VPN solutions, as it can work easily through firewalls and is widely supported by web browsers, making it convenient for users. Furthermore, SSL/TLS can provide a secure connection for various types of traffic besides just web data, which enhances its utility in VPN implementations.

Other protocols mentioned in the choices serve different functions. For instance, while UDP (User Datagram Protocol) can be used for certain types of VPNs (like those using the OpenVPN protocol), it is not primarily the protocol itself that secures communication. FTP (File Transfer Protocol) and HTTP (Hypertext Transfer Protocol) are protocols designed for transferring files and web content, respectively, and by themselves do not offer secure communication features without the addition of layers like FTP over SSL/TLS or HTTPS (HTTP Secure).