Is there a simple way to convert a prefab into some kind of hash ID?

For example, if I want to know if two different game objects were instantiated from the same prefab. These objects may be vastly different later on during runtime, but is there a way I can initialize them with with some kind of hash ID from the object they were created with?

If I understand what you’re trying to do correctly, you don’t necessarily need a hash id, just a variable for the game object. For example you can instantiate a gameobject like this:

GameObject myObject = Instantiate(prefab, position, rotation) as GameObject;

This way you can just refer to your myObject variable later on down the road whenever you want to change something or refer to something in that prefab gameobject.