What TCP port is commonly associated with secure communication in networks?

TCP port 443 is commonly associated with secure communication in networks, specifically for HTTPS (Hypertext Transfer Protocol Secure). This protocol is used for securely transmitting data over the internet by encrypting the communication between a client (typically a web browser) and a server. The use of SSL/TLS (Secure Sockets Layer/Transport Layer Security) with HTTPS ensures that data such as user credentials, payment information, and personal details remain private and secure during transmission.

While other ports mentioned may be associated with secure communication in specific contexts—such as port 22 for SSH and port 636 for LDAPS—port 443 is the standard for secure web data transfer and is widely recognized in the context of web security. TCP port 3389 is primarily used for Remote Desktop Protocol (RDP), allowing remote desktop connections, but it does not emphasize the secure transmission of web data in the same way that port 443 does.