Which of the following would be used as a secure substitute for Telnet?

A.
SSH

B.
SFTP

C.
SSL

D.
HTTPS

Explanation:
Secure Shell (SSH) is a tunneling protocol originally designed for Unix systems. It uses encryption to
establish a secure connection between two systems. SSH also provides alternative, security-equivalent
programs for such Unix standards as Telnet, FTP, and many other communications-oriented applications.
SSH is available for use on Windows systems as well. This makes it the preferred method of security for
Telnet and other cleartext oriented programs in the Unix environment.
Incorrect Answers:
B: SFTP is for File transfers, not for telnet.
The SSH File Transfer Protocol (also Secure File Transfer Protocol, or SFTP) is a network protocol that
provides file access, file transfer, and file management functionalities over any reliable data stream.
C: SSL is used to provide a secure channel, not to establish a telnet connection.
The Secure Socket Layer (SSL) and Transport Layer Security (TLS) is the most widely deployed security
protocol used today. It is essentially a protocol that provides a secure channel between two machines
operating over the Internet or an internal network.
D: HTTPS is not used for telnet connections.
HTTPS is a communications protocol for secure communication over a computer network, with especially
wide deployment on the Internet.

Dulaney, Emmett and Chuck Eastton, CompTIA Security+ Study Guide, 6th Edition, Sybex, Indianapolis,
2014, pp. 76, 91, 268-269, 271, 274