A method for the distributed transmission of a communication flow, - in which the communication flow takes place from a first to a second communication unit (201, 202) at least monodirectionally, - wherein the first and second communication units (201, 202) are capable of transmitting the communication flow by means of at least two different communication paths (203, 204, 205, 206, 211, 212, 213, 214), and - wherein the communication flow comprises at least one vehicle-to-X message, - wherein the communication flow is subdivided into at least two partial communication flows by the first communication unit prior to transmission, - wherein the at least two partial communication flows are transmitted from the first to the second communication unit (201, 202) while being distributed among the at least two different communication paths (203, 204, 205, 206, 211, 212, 213, 214), - wherein the at least two partial communication flows are reassembled by the second communication unit after reception, characterized in that the second communication unit, when assembling the at least two partial communication flows, checks whether the at least two partial communication flows can be assembled to form a reliable joint communication flow, wherein the second communication unit performs said check by ascertaining whether the at least two partial communication flows correspond to the communication flow previously subdivided by the first communication unit, - wherein the vehicle-to-X message consists of a payload part and a security data part, - wherein the security data part comprises information on the assessment of the authenticity and reliability of the vehicle-to-X message by the receiver, and the payload part and the security data part are transmitted via respectively different communication paths of the at least two communication paths (203, 204, 205, 206, 211, 212, 213, 214), wherein the joint communication flow is classified as reliable if the security data part is assignable to the payload part, and wherein the vehicle-to-X message is classified as unreliable if the security data part is not assignable to the payload part. - in which the communication flow takes place from a first to a second communication unit (201, 202) at least monodirectionally, - wherein the first and second communication units (201, 202) are capable of transmitting the communication flow by means of at least two different communication paths (203, 204, 205, 206, 211, 212, 213, 214), and - wherein the communication flow comprises at least one vehicle-to-X message, - wherein the communication flow is subdivided into at least two partial communication flows by the first communication unit prior to transmission, - wherein the at least two partial communication flows are transmitted from the first to the second communication unit (201, 202) while being distributed among the at least two different communication paths (203, 204, 205, 206, 211, 212, 213, 214), - wherein the at least two partial communication flows are reassembled by the second communication unit after reception, - wherein the vehicle-to-X message consists of a payload part and a security data part, - wherein the security data part comprises information on the assessment of the authenticity and reliability of the vehicle-to-X message by the receiver, and the payload part and the security data part are transmitted via respectively different communication paths of the at least two communication paths (203, 204, 205, 206, 211, 212, 213, 214), wherein the joint communication flow is classified as reliable if the security data part is assignable to the payload part, and wherein the vehicle-to-X message is classified as unreliable if the security data part is not assignable to the payload part.