Key and lock device

A method of authorizing a key or lock device comprises the following steps: a first user device and a first system device used in a first level of a lock system, such as at a manufacturer, are created. A first encryption key is stored in the first user device and the first system device. When the user device is to be shipped to a second level of the lock system, such as a locksmith, an authentication process is carried out between the first user device and the first system device using the first encryption key stored therein. In case the authentication process was successful, a software operation is carried out by the first system device, by which the first encryption key stored in the first user device is replaced by a second encryption key. This second encryption key is stored in second system and user devices used in the second level of the lock system, thereby making the first user device operable with the second system and user devices. This prevents unauthorized use of keys and locks.