Lock system and the creation of electronic keys in the lock system

Method and lock system for creating an electronic key, which lock system comprises at least one lock and a server. In the solution according to the invention a request for creating an electronic key is received from the device of a user administering the lock and, in response to the request, the reference data of the electronic key is sent to the device of the user administering the lock. After this a request for delivering the electronic key is received from the mobile device, to which request the reference data of the electronic key is attached, and an electronic key is created and encrypted. Finally, the encrypted electronic key is sent to the mobile device from which the request for delivering a key was received.