ZyXEL MI-7248 User Guide - Page 233

SSH Overview

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Chapter 38 Access Control 38.4 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 121 SSH Communication Example 38.4.1 How SSH works The following table summarizes how a secure connection is established between two remote hosts. Figure 122 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. The client automatically saves any new server public keys. In subsequent connections, the server public key is checked against the saved version on the client computer. 2 Encryption Method MS-7206 User's Guide 233

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Chapter 38 Access Control
MS-7206 User’s Guide
233
38.4
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 121
SSH Communication Example
38.4.1
How SSH works
The following table summarizes how a secure connection is established between two remote
hosts.
Figure 122
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.
The client automatically saves any new server public keys. In subsequent connections,
the server public key is checked against the saved version on the client computer.
2
Encryption Method