Which term refers to the network protocol that is used for secure remote login and is commonly associated with encrypted command-line access?

• A. Secure Shell (SSH)
• B. Secure Sockets Layer (SSL)
• C. Secure Copy (SCP)
• D. Secure File Transfer Protocol (SFTP)

Answer: (A)

Secure remote login with encrypted command-line access is provided by Secure Shell (SSH). SSH creates an encrypted channel between your device and a remote host, authenticates the remote system (and optionally you), and lets you log in, execute commands, or start a shell securely over the network. It typically runs on port 22 and uses public-key cryptography for authentication and symmetric encryption for the session to protect confidentiality and integrity. The other options serve different purposes: SSL/TLS is used mainly to secure web traffic, not interactive shell sessions; SCP and SFTP are file-transfer protocols that operate over SSH but do not themselves provide an interactive login shell.