How Ssh Works - ZyXEL Communications MGS-3712/MES-3728 User Manual

Chapter 34 Access Control

34.5 How SSH works

The following table summarizes how a secure connection is established between
two remote hosts.
Figure 173 How SSH Works
Host Identification
1
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.
Encryption Method
2
Once the identification is verified, both the client and server must agree on the
type of encryption method to use.
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