Vehicle system having: - a security-critical control device, - a secure communication device having a predefined vehicle interface which is designed to couple the secure communication device to the security-critical control device using signalling technology, - a vehicle bus which couples the vehicle interface of the secure communication device to a predefined interface of the security-critical control device using signalling technology, wherein the secure communication device is a secure communication device for a vehicle, - which has a housing with a housing securing means, - which has a predefined radio interface arranged in the housing and at least one associated antenna element for coupling the secure communication device to at least one predefined further device using signalling technology, wherein the at least one antenna element is designed to transmit and/or receive signal waves of a predefined frequency band and is at least partially arranged in the secure housing, - which has the predefined vehicle interface arranged in the housing for coupling the secure communication device to at least one security-critical control device of the vehicle using signalling technology, - which has a cryptographic functional unit which is arranged in the housing and has at least one cryptographic key and/or is designed to execute at least one cryptographic function, - and which is designed to cryptographically evaluate data which are received by the secure communication device via the radio interface and/or via the vehicle interface by means of the cryptographic functional unit and/or to securely store said data and/or to securely forward said data via the radio interface and/or via the vehicle interface to the one security-critical control device or to a further security-critical control device or to the one further device or to a second further device, and wherein the vehicle system is characterized in that - the secure communication device is also designed to compare satellite data which are received from different navigation satellite systems via the radio interface and are representative of a position of the vehicle and/or an item of speed information relating to the vehicle and/or a time and/or a date, - the secure communication device is also designed to check an integrity of the satellite data on the basis of the comparison of the satellite data, with the result that authenticated satellite data can be provided for the security-critical control device and manipulation security of the security-critical control device can therefore be improved as a result of increased data redundancy, and - the secure communication device is also designed to securely carry out the comparison of the satellite data and the integrity check by means of the cryptographic functional unit and to securely store the data whose integrity has been checked. - a security-critical control device, - a secure communication device having a predefined vehicle interface which is designed to couple the secure communication device to the security-critical control device using signalling technology, - a vehicle bus which couples the vehicle interface of the secure communication device to a predefined interface of the security-critical control device using signalling technology, - which has a housing with a housing securing means, - which has a predefined radio interface arranged in the housing and at least one associated antenna element for coupling the secure communication device to at least one predefined further device using signalling technology, wherein the at least one antenna element is designed to transmit and/or receive signal waves of a predefined frequency band and is at least partially arranged in the secure housing, - which has the predefined vehicle interface arranged in the housing for coupling the secure communication device to at least one security-critical control device of the vehicle using signalling technology, - which has a cryptographic functional unit which is arranged in the housing and has at least one cryptographic key and/or is designed to execute at least one cryptographic function, - and which is designed to cryptographically evaluate data which are received by the secure communication device via the radio interface and/or via the vehicle interface by means of the cryptographic functional unit and/or to securely store said data and/or to securely forward said data via the radio interface and/or via the vehicle interface to the one security-critical control device or to a further security-critical control device or to the one further device or to a second further device, - the secure communication device is also designed to compare satellite data which are received from different navigation satellite systems via the radio interface and are representative of a position of the vehicle and/or an item of speed information relating to the vehicle and/or a time and/or a date, - the secure communication device is also designed to check an integrity of the satellite data on the basis of the comparison of the satellite data, with the result that authenticated satellite data can be provided for the security-critical control device and manipulation security of the security-critical control device can therefore be improved as a result of increased data redundancy, and - the secure communication device is also designed to securely carry out the comparison of the satellite data and the integrity check by means of the cryptographic functional unit and to securely store the data whose integrity has been checked.