ZyXEL Communications ZyWALL5UTM 4.0 27.5 SSH, 27.6 How SSH works

ZyWALL 5/35/70 Series User’s Guide

Figure 215 Common ZyWALL Certificate

27.5 SSH

Unlike Telnet or FTP, which transmit data in clear text, SSH (Secure Shell) is a secure communication protocol that combines authentication and data encryption to provide secure encrypted communication between two hosts over an unsecured network.

Figure 216 SSH Communication Example

27.6 How SSH works

The following table summarizes how a secure connection is established between two remote hosts.

437 Chapter 27 Remote Management