Which protocol is used for secure communication over a computer network?

• A. HTTP
• B. FTP
• C. SSH
• D. SMTP

Answer: (C)

The protocol used for secure communication over a computer network is SSH, which stands for Secure Shell. SSH provides a secure channel over an unsecured network by using encryption to protect the data being transmitted. This is particularly important for remote login and command execution, allowing users to safely access servers and other devices without the risk of eavesdropping or data theft.

Unlike other protocols, such as HTTP, which is not secure by default, SSH encrypts the entire communication session between the client and the server. This means that any data, including passwords and commands, is safeguarded against interception. FTP, primarily used for file transfer, does not ensure confidentiality or data integrity unless it is paired with additional security measures. SMTP is the standard protocol for sending emails, but, like HTTP and FTP, it does not inherently provide secure transmission methods.

In summary, SSH stands out as the appropriate choice for secure communication in network environments due to its encryption capabilities and focus on security during remote access and administration.