Which protocol is used for unencrypted remote login on port 23?

Which protocol is used for unencrypted remote login on port 23?

• A. Telnet Protocol
• B. SSH
• C. HTTP
• D. POP3

Answer: (A)

Remote login without encryption is provided by Telnet, which uses TCP port 23. Telnet transmits the session in plaintext, including usernames and passwords, making it easy for attackers to capture credentials on the network. That insecure behavior is precisely why it’s associated with unencrypted remote management. In contrast, SSH offers encrypted remote login and typically runs on port 22, providing a secure alternative. The other options serve different purposes—HTTP for web traffic (port 80, or 443 for HTTPS) and POP3 for email retrieval (ports 110 or 995)—and do not establish a remote login session.

Remote login without encryption is provided by Telnet, which uses TCP port 23. Telnet transmits the session in plaintext, including usernames and passwords, making it easy for attackers to capture credentials on the network. That insecure behavior is precisely why it’s associated with unencrypted remote management. In contrast, SSH offers encrypted remote login and typically runs on port 22, providing a secure alternative. The other options serve different purposes—HTTP for web traffic (port 80, or 443 for HTTPS) and POP3 for email retrieval (ports 110 or 995)—and do not establish a remote login session.