A pre-shared private Update Key is used, along with a Key Wrap algorithm, to encrypt the Session Keys during the Session Key Change process. ClearSCADA supports one Update Key per outstation (for the ‘Default User’). You set the Update Key using the Set Update Key pick action or method. (With DNP3 devices with which ClearSCADA communicates using a DNP3 Extension Driver, additional means of setting the Update Key may be supported. Any such additional functionality is explained in the relevant DNP3 extension driver guide.)
It is imperative that the Update Key is kept secret and is not stored or transmitted in any way that could permit unauthorized access to the key.