SSL/TLS (Secure Sockets Layer/Transport Layer Security) is the protocol used for secure communication over the internet. SSL/TLS provides encryption and authentication to ensure that data transmitted between a client and server is secure and protected from eavesdropping or tampering. FTP (File Transfer Protocol), POP3 (Post Office Protocol version 3), and SNMP (Simple Network Management Protocol) are not specifically designed for secure communication over the internet.