Abstract: A method for transmitting user data (D) between subscribers in a network (N) by means of data messages (4) has the following steps: allocating in each case one message counter (TC) to the data messages (4), the message counter (TC) being specified individually for each data message (4), and ignoring the contents of user data (D) of a subscriber who receives a data message (4) containing the user data (D) if the message counter (TC) is not plausible on the basis of previously received data messages (4).

Abstract: A method for specifying transmitting times for cyclically sending out data messages (3) in a data transmission network (1) is disclosed, which has a plurality of subscriber devices (2) containing transmitting and/or receiving units networked together, comprising allocating a message counter to the individual data messages (3) of a transmitting subscriber device (2) in such a manner that the message counters for a sequence of data messages (3) differ from one another, individually specifying a transmitting time (STx,y+1) following a transmitting time (STx,y), for sending out a next data message (3) for each subscriber device transmitting the data message (3), and each subsequent transmitting time of the transmitter, in such a manner that the times between in each case two successive transmitting times (STx,y, STx,y+1) of a cycle continuously varies for each transmitting subscriber device (2), and specifying the transmitting times by means of a function for generating a pseudo random number.