Patent ID: 8639925

Claim:
A method for protecting a sensor device and sensor data of the sensor device from manipulation, the method comprising: sending, by a control unit, to the sensor device, and during authentication of the sensor device, a first data packet including a first time-variant parameter concatenated with an identity of the control unit; receiving, by the control unit, a second data packet, the second data packet having been generated by the sensor device by: encrypting the first data packet using a key of determined bit length, wherein, when a bit length of the first data packet is less than the bit length of the key, the encrypting includes padding the first data packet with additional bits; and concatenating a first determined number of bits of the encrypted first data packet with an identity of the sensor device; comparing, by the control unit, the second data packet with a calculated value of the first determined number of bits of the encrypted first data packet; and receiving, by the control unit, the sensor data, together with an integrity protection value, the integrity protection value having been generated by the sensor device based on a second time-variant parameter generated from a second determined number of bits of the first time-variant parameter; wherein one of a random number, a part of the random number, and a number obtained from the random number by a function is utilized as the time-variant parameters in the authentication of the sensor device.