Smart locks, like the traditional locks, need two main parts to work: the lock and the key. In the case of these electronic locks, the key is not a physical key but a smartphone or a special key fob configured explicitly for this purpose which wirelessly performs the authentication needed to automatically unlock the door.

Smart locks allow users to grant access to a third party by the means of a virtual key. This key can be sent to the recipient smartphone over standard messaging protocols such as e-mail or SMS. Once this key is received the recipient will be able to unlock the smart lock during the time specified previously by the sender.

Smart locks are able to grant or deny access remotely via a mobile app. Certain smart locks include a built-in WiFi connection that allows for monitoring features such as access notifications or cameras to show the person requesting access. Some smart locks work with a smart doorbell to allow the user to see who and when someone is at a door.

Smart locks may use Bluetooth SMART and SSL to communicate, encrypting communications using 128/256-bit AES.