A method for safeguarding a network made up of at least one first device and one second device. The first device derives a first challenge from physical properties of a first communication channel between the first device and the third device. In addition, the first device transmits the first challenge to the second device via a second communication channel between the first device and the second device. The first device receives a first response, corresponding to the first challenge, from the third device via the first communication channel and receives a second response, corresponding to the first challenge, from the second device via the second communication channel. The first device compares the first response and the second response to one another to verify that the second device is communicating with the third device.