Nøkkel- og låsinnretning

A key and lock device comprises a key and a standalone lock. The key has an electronic circuitry with a first memory and a contact. The lock has electronic circuitry with a memory, and a contact arranged to co-operate with the key's first contact. A blocking mechanism is adapted to block operation of the lock unless an authorized key is inserted in the lock. The memory of the key stores a public identification item of the key identifying a group of keys having identical mechanical codes. In the memory of the lock, there is provided a list of the public and secret identification items of authorized keys and a list of the public identification item of non-authorized keys. A key is authorized if the public and secret identification items are present in the list of authorized keys and the public identification item thereof is absent in the list of non-authorized keys.