Patent ID: 8538624

Claim:
A method for transmitting data via a transmission path between a tachograph arranged in a vehicle and a data processing device remote from the vehicle, comprising: receiving by the tachograph an enquiry sent by the data processing device; encrypting by the tachograph, only when the enquiry includes an encryption request, data to be sent by the tachograph to the data processing device, the encrypting being based at least in part on the encryption request; transmitting only the encrypted data by the tachograph to the data processing device via a first path section arranged between the tachograph and a communication controller arranged in the vehicle and via a second path section arranged between the communication controller and the data processing device and comprising an air link when the enquiry includes the encryption request, whereby the step of encrypting is performed only when the enquiry includes the encryption request, allowing an increased transmission rate when the encryption request is not present.