A method for establishing a communication channel (17) between a predetermined number of selected devices (3;5). Each of the devices has its own identity. The establishing of the communication channel is done by a pairing via a server (1). Said devices have a pairing operational mode and a communication operational mode. The method comprises the steps of: —setting each of the devices in the pairing operational mode, —agreeing on the choice of a pairing signal (19a;19b), —selecting the agreed upon pairing signal (19a) on each of the devices, which devices transmit their identity and the agreed upon pairing signal (19a) to the server (1), —if the server (1) in a predetermined time interval determines that more than the predetermined number of selected devices have transmitted the agreed upon pairing signal (19a; 19b) than repeating the above second and third steps, wherein a next pairing signal is agreed upon, until the server (1) determines that only the predetermined number of selected devices have transmitted an identical sequence of pairing signals (19a;19b), —establishing the communication channel (17) between the devices by the server (1), and —setting each of the devices in the communication operational mode. The achieved communication channel is very secure. A system comprises a server (1) and a predetermined number of selected devices (3;5), wherein during use a communication channel (17) between the first device (3) and the second device (5) is established via the server (1) according to the method of the invention.