The dwarven gods true names can only be known by dwarves. They are referred to by nicknames in the presence of non-dwarves. I.E. Gudurran( Allfather) Baenna ( Hearthmother) Dudrak ( Ore), etc. No torture or magic or direct intent can reveal their true names to non-dwrves.
What if dragon-sightings and evidence of such was treated with the same skepticism and mockery as modern UFO sightings? More for a low magic world where dragons 'dont' exist.