Door with encrypted key (auto close)

A simple system that makes a door open when the correct key is in the hopper. The key is a name tag with a random number as name. This system are using hoppers that only will let through name tags with the correct name, when you put 22 items of the same sort the hopper will only let through that type of items (example: 22 stone in the hopper, only stone blocks will be able to go trough the hopper) one more thing, you need at least 2 hoppers for this system to work.
 For more information download the world save.