A method and system for detecting manipulation when control data are transmitted from a first control unit to a second control unit via a network, which includes generating integrity check information data for the control data transmitted by the first control unit via an integrity check generating unit on the transmitter side, calculating a cryptographic checksum for the integrity check information data generated on the transmitter side via the integrity check generating unit, transmitting the integrity check information data and the cryptographic checksum to an integrity check verifying unit that verifies the cryptographic checksum on the receiver side, generating integrity check information data on the receiver side for the control data received by the second control unit using the integrity check verifying unit, and comparing the integrity check information data and the integrity check information data with the cryptographic checksum to detect the manipulation of the transmitted control data.