Stand on the chest, trapped chest, furnace, shulker box, dispenser, dropper, brewing stand, or hopper you want to lock. Then go to an anvil and rename any item to be your password. Replace [Key] with your password. Now you can only open that storage device while holding the item renamed to be your password (Your Key). It will say "[name of storage container] is locked" if you try to open it with anything else. Note: Shulker Boxes will remain locked even after you mine them and place them somewhere else.