This tutorial shows how to build a Lock & Key / Password System, which you can attach to any Redstone-powered item / mechanism. The most obvious use for it is to create a Locking Door. 

How the Lock & Key works is, it sorts for a unique item. It's unique because it is renamed on an Anvil, and then will not stack with similar but differently-named items (ex: a tripwire hook renamed "Key 123" will not stack with a tripwire hook named "Key XYZ"). Then, when you put in the correct item, it puts out a redstone signal.

Because you create this Unique Item by renaming an item on an Anvil, you can rename it anything which fits, making it work very similarly to a Password for a computer / account.

You then use that redstone signal to do whatever you need; in this tutorial, I show how to use the signal to make a Locking Door. I also show how to return your key when you want to re-lock your Lock & Key Mechanism.

If you enjoyed this tutorial or just want to show support, please subscribe to my YouTube channel or to my posts here on PlanetMinecraft!

Quick Review:

• Lock & Key / Password using a renamed Item as a Unique Key
  
• Can be used to power any Redstone device / mechanism
  
• This tutorial shows how to connect it to a locking door, and how to build the mechanism itself