Which protocol is often used to encrypt traffic in a VPN?

IPSec is a widely used protocol for encrypting traffic in a Virtual Private Network (VPN). It provides security at the network layer, allowing for secure communication over the Internet by encrypting and authenticating each IP packet in a communication session. This ensures that the data being transmitted is protected from eavesdropping and tampering.

IPSec can operate in two modes: transport mode, which encrypts only the payload of the IP packet, and tunnel mode, which encrypts the entire packet. This flexibility allows it to be suited for different types of network configurations and security needs. Given its robust encryption capabilities, it is a foundational component of many VPN implementations, enabling secure access for remote users and sites.

Other protocols like HTTP, SFTP, and FTP serve different purposes. While HTTP is used for transferring web pages and does not provide encryption by default, SFTP is a secure file transfer protocol that operates over a secure connection but is not a protocol specifically designed for VPN traffic. FTP, on the other hand, is used for transferring files without built-in encryption, making it unsuitable for secure communications in a VPN context.