There are several different methods that can be used to authenticate the user when connecting to a remote host computer. In most situations, the most convenient user authentication methods are public-key authentication, certificate authentication or authentication with hardware tokens (smart cards).
Figure : The User Authentication page of the Settings dialog
To use public-key authentication, you must upload your public key to your home directory on the remote host computer. You also have to modify your authorization file to allow connecting with the new key. For more information, see Section Manually Editing the Authorization File. By default, all available public keys and certificates are offered to the remote host computer during public-key authentication.
Certificate authentication is more secure than the traditional public-key authentication, as the system verifies that the user certificate has been issued by a trusted certification authority (CA) and that the certificate has not been revoked. Certificate authentication is also more convenient, as no local database of users' public keys is required on the remote host computer.
Probably the most convenient method is to use a hardware token (smart card) that must be inserted into a card reader device to authenticate the user.
Token Insertion and Removal
The following options specify how hardware tokens are used for user authentication:
Disconnect automatically when token is removed
Select this check box to immediately terminate the connection if your token is removed from the card reader device. This ensures that a connection will be active only when a token is inserted.
Connect automatically when token is reinserted
Select this check box to automatically reconnect when your token is inserted into the card reader device. This check box is active only if the Disconnect automatically when token is removed check box is selected.
Seconds to wait before disconnecting
In the text field you can specify how many seconds the connection will remain open if your token is removed from the card reader device. The default value is zero. This field is active only if the Disconnect automatically when token is removed check box is selected.