ZyXEL Communications GS-2724 - Manual (Page 198)

Chapter 29 Access Control
GS-2724 User’s Guide
198
29.4 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 100 SSH Communication Example
29.5 How SSH works
The following table summarizes how a secure connection is established between two remote
hosts.
Figure 101 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.