You are able to select a permanent Whiteboard password through the Whiteboard installation wizard
After installing Dolphin Whiteboard assistant it will prompt you to enter your preferred settings. Within this window you can specify the port, window highlight and also the password.
Select Use a random password to have a secure password generated for the session.
For setting a permanent password select the option choose my own password.
If you wish to edit the password after setting your own password select the 3 line hamburger menu in the top right of the Dolphin Whiteboard assistant window to re-open the settings for editing your connection.