We use key cards to access your rooms. These are better than normal keys because anyone can copy a normal key. The keycards expire at a certain time, so in the unlikely event that a copy is able to be made, it will only last a short time. You can even keep your keycards as a souvenir. You should always show your card to reception when you walk past, and you will need to use your keycard to enter the hostel after midnight.