While Towny is great for protecting areas of land, chest protection is even better for protecting chests, furnaces, barrels, doors, etc. Simply place a sign on a chest, furnace, barrel, door, etc. and it will automatically create a private sign for the block you wish to protection. You can right click a sign and type /blocklocker [linenumber] [name] to add a player to your protected block. Chests can only be locked in claimed land.