Device for locking and immobilising an automobile

The device has a motor vehicle opening locking/unlocking device (3) for controlling locking/unlocking of openings (17) of a motor vehicle (1) following reception of authentication data of a key (7) via a reading interface (9). A motor vehicle starting system (5) controls starting of the vehicle following reception of the authentication data via the reading interface. A radiofrequency communication interface (11) of the key and the reading interface process the exchange of the authentication data of the key according to a Near Field Communication (NFC)protocol.