What is the secure version of Telnet?

The secure version of Telnet 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 crucial because Telnet transmits data, including login credentials, in plaintext, making it vulnerable to interception by attackers.

SSH not only encrypts the session but also offers enhanced authentication methods, such as public key authentication, which adds an extra layer of security compared to Telnet. This makes SSH the preferred choice for remote administration and secure file transfers, effectively replacing Telnet in most applications that require secure remote access.

In contrast, the other options do not fulfill the role of a secure Telnet alternative. Rlogin is a remote access protocol that lacks the encryption capabilities provided by SSH. SCP, or Secure Copy Protocol, is used for securely transferring files but does not offer the command-line interface and session management capabilities that SSH provides. FTP, or File Transfer Protocol, likewise does not include security features and transmits data in plaintext, making it unsuitable for secure communication.