What protocol uses port 22 for encrypted communication?

The protocol that uses port 22 for encrypted communication is SSH, or Secure Shell. SSH is primarily used to securely access and manage network devices and servers over an untrusted network. It provides a secure encrypted connection, ensuring that both the commands being sent and the data being received are protected from eavesdropping or tampering.

SSH is commonly used for remote login, secure file transfers, and executing commands on remote systems securely. Unlike protocols such as Telnet, which transmits data in plaintext, SSH encrypts all communications, making it a preferred choice for secure administrative access.

In contrast, the other mentioned protocols use different ports and serve different purposes: Telnet operates on port 23 and does not provide encryption, making it insecure for transmitting sensitive information; DHCP uses port 67 and is responsible for dynamic IP address allocation; SMTP, which operates on port 25, is designed for sending emails and does not inherently provide secure transmission unless used in conjunction with other protocols like STARTTLS.