Method and device for authenticating transmitted user data

An arrangement for transmission of payload data that implements real-time applications between at least one first communication device and at least one second communication device which are designed in such a way that the payload data are transmitted as data packets during a communication connection, the data packets comprising first data packets, second data packets, and third data packets, the arrangement comprising:

• a first communication device;
• a second communication device, the second communication device having a communication connection with the first communication device;
• at a first time period, the first communication device embedding at least one first data packet of the first data packets with first authentication information enabling authentication of the first communication device;
• the first communication device transmitting the first data packets to the second communication device;
• the second communication device receiving the first data packets and extracting the first authentication information embedded within the at least one first data packet of the first data packets;
• upon a determination that the first authentication information authenticates the first communication device, the second communication device maintaining the communication connection and forwarding the first data packets for appropriate processing;
• at a second time period that is after the first time period, and during the transmission of data packets between the first and second communication devices, the first communication device embedding at least one second data packet of the second data packets with first authentication information enabling authentication of the first communication device;
• the second communication device receiving the second data packets an amount of time after the receipt of the first data packets and forwarding of the first data packets;
• the second communication device extracting the first authentication information embedded within the at least one second data packet of the second data packets;
• and
• upon a determination that the first authentication information authenticates the first communication device, the second communication device maintaining the communication connection and forwarding the second data packets for appropriate processing;
• at a third time period that is after the second time period, and during the transmission of data packets between the first and second communication devices, the first communication device embedding at least one third data packet of the third data packets with first authentication information enabling authentication of the first communication device;
• the second communication device receiving the third data packets an amount of time after the receipt of the second data packets and forwarding of the second data packets;
• the second communication device extracting the first authentication information embedded within the at least one third data packet of the third data packets;
• and
• upon a determination that the first authentication information authenticates the first communication device, the second communication device maintaining the communication connection and forwarding the third data packets for appropriate processing.