Patent ID: 8222989

Claim:
A method for the protection of a movable item ( 100 ) against unauthorized use, wherein the movable item is an aircraft, vehicle, a motor vehicle, or a construction machine, the method comprising the following steps: cryptographically authenticating the movable item to an external computer system ( 108 ), wherein the cryptographical authentication is performed using an asymmetric key pair ( 126 , 128 ) which is associated with the movable item, wherein the asymmetric key pair comprises a secret key ( 128 ) and a public key ( 126 ), wherein a code is obtained from one or more identifiers of electronic components ( 120 ) of the movable item, wherein the code is signed using the secret key ( 128 ), wherein the code is used to identify the movable item, sending the signed code and a certificate ( 130 ) from the movable item to the external computer system, wherein the certificate contains the public key, wherein the certificate contains a code or an identifier identifying the movable item, receiving the signed code and the certificate ( 130 ) from the movable item by the external computer system, checking validity of the signed code using the public key by the external computer system, wherein the signed code is valid if the signed code matches the code of the certificate or if the signed code matches a code which is associated, in an association table ( 136 ), with the identifier contained in the certificate, wherein the association table is stored in the external computer system, wherein the signed code is compared with the code in the certificate when the certificate contains the code, and wherein the signed code is compared with the code in the association table when the certificate contains the identifier identifying the movable item, performing a check by the external computer system to determine whether a block is stored for the movable item, sending a use signal from the external computer system to the movable item in order to allow use of the movable item when no block is stored for the movable item, wherein the use signal is sent only if the signed code is valid, and sending a block signal from the external computer system to the movable item, wherein the block signal is sent only if a block is stored for the movable item or the signed code is invalid.