An application developer is designing an application involving secure transports from one service to another that will pass over port 80 for a request. Which of the following secure protocols is the…

FTPS (FTP Secure) uses ports 990 (implicit) or 21 (explicit) for control connections and is designed specifically for file transfer, not general application request transport over port 80.

SFTP (SSH File Transfer Protocol) operates over port 22 as it runs over SSH, and is purpose-built for secure file transfer rather than securing general application request traffic over port 80.

SSL (Secure Sockets Layer) can operate over port 80 when used in certain application-layer tunneling or upgrade scenarios, and is the foundational secure transport protocol used to encrypt HTTP traffic. In the context of application-to-application secure transport over port 80, SSL (and its successor TLS) is the protocol developers implement to secure the communication channel without changing the default HTTP port.

LDAPS (LDAP over SSL) uses port 636 by default and is specifically designed for securing directory service queries, not for securing general application-to-application transport over port 80.