Depends on if you're talking a few extra seconds or minutes. If you're only looking to buy a little bit of time, a second deadbolt installed higher up on the door and with a stronger strikeplate will delay entry. That prevents someone from kicking directly where the lock is, and the flexibility of the door will work against them. Eventually the door will break, you could upgrade the door to something stronger, but then the weak point becomes the frame. But the difference between a one kick entry and two or three kicks might be enough.