Which of the following is a network protocol that allows data to be exchanged using a secure channel between two networked devices?

SSL (Secure Sockets Layer) is a cryptographic protocol for securing web communications, but it is not itself a general-purpose network protocol for device-to-device secure channel communication in the way SSH is.

FTP (File Transfer Protocol) transfers files between hosts but does not provide a secure channel - it transmits credentials and data in plaintext.

SSH (Secure Shell) is a cryptographic network protocol specifically designed to allow data exchange over a secure, encrypted channel between two networked devices. It uses public-key cryptography to authenticate hosts and users, and it encrypts all traffic to prevent eavesdropping and man-in-the-middle attacks. SSH operates on TCP port 22 and is the standard for secure remote administration.

SFTP (SSH File Transfer Protocol) is a file transfer subsystem that runs over an SSH connection, not an independent network protocol for general secure channel communication.