Data transmission unit for a vehicle

1. A method for transmitting data between a vehicle and a terminal, in which data to be transmitted are transmitted on the basis of at least one private key stored by a security module in a vehicle key for the vehicle, the vehicle key also comprising at least one interface for communicating with the terminal and/or the vehicle and at least one microprocessor, and the microprocessor being used to check a trustworthiness of the data to be transmitted via the interface, in which data which are to be transmitted from the terminal to the vehicle are first of all transmitted to the interface of the vehicle key via a secure channel, whereupon at least one first digital signature is created by the security module included in the vehicle key and the data to be transmitted to the vehicle are sent back to the terminal together with the at least one first digital signature, whereupon the terminal forwards the data to be transmitted to the vehicle with the at least one first digital signature, data to be transmitted from the vehicle to the terminal being provided with at least one second digital signature and being transmitted to the terminal, the terminal forwarding data received in this manner to the interface of the vehicle key for a check for trustworthiness, and the vehicle key forwarding a result of the check for trustworthiness to the terminal.

2. The method as claimed in claim 1 , in which data which are to be transmitted from the vehicle to the terminal and/or to the vehicle key are transmitted by a system which is included in the vehicle and comprises an antenna and a transceiver.

3. The method as claimed in claim 2 , in which the system is solely used for communication in a vehicle-specific communication standard.

4. The method as claimed in claim 2 , in which the system is used for communication in any desired communication standard.