Inside an SQL Forms instance you have Security management tab.
To force access to only authenticated users select from Security tab View
I mean uncheck Acquire permission settings? for View and check only
Authenticated or your preffered Zope Role.
That means View right is checked for Authenticated and is not possibile
to Acquire permission settings from parents.
The next step in your security is to change security check script you selected from
Options tab with something who check current (authenticated) user
to be someone or to be member of some group