How Can I Send You Your Birthday Present, and Know That You Won’t Open it until your Birthday?

How can we properly secure things? Well, we sure make the effort so large to crack them, that no-one could afford the effort to break it. If is takes me a little bit of work to change the clock on a computer, it is probably worth it to me to do it, if there is a good reward. But if I require to purchase all the computing power in…