Hi Tonia,
When you initially run the accounting setup commands your define a shared secret as part of that.
http://help.prognosis.com/dr/Prognosis_11-2/mergedProjects/Unified_Communications/HTML_Files/Session_Border_Controllers/Configuration/SBC_CUBE-RadiusAccountConfig.htm?zoom_highlight=radius
I.e.
In the below command, the shared secret is set to 'Prognosis'
radius-server host 10.116.1.73 auth-port 1812 acct-port 1813 key Prognosis
This is the entry you configure to the passwords configuration in prognosis
I.e
Radius: entry