Ssh Overview; How Ssh Works; Figure 129 Ssh Communication Example; Figure 130 How Ssh Works - ZyXEL Communications GS-4012F/4024 User Manual

GS-4012F/4024 User's Guide

33.4 SSH Overview

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 129 SSH Communication Example

33.5 How SSH works

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

Figure 130 How SSH Works

1 Host Identification
The SSH client sends a connection request to the SSH server. The server identifies itself
with a host key. The client encrypts a randomly generated session key with the host key
and server key and sends the result back to the server.
211 Chapter 33 Access Control