Adjusting authenticated time past 5 minutes

I’m writing an app where some parts can take a long time, way past five
minutes, so when I do bits “with administrator privileges” the user can be
required to reauthenticate.

I swear I read somewhere how to change the timeout time, but I cannot find
it now. Does anyone have a suggestion for this?

I have no idea if this will work with administrator privileges, but try this

with timeout of 600 seconds
	-- do stuff here
end timeout

this affects only applications which send AppleEvents, but not shell scripts