A device and a method for authorizing access to a service on a first device upon detection of a second device located in near proximity, while preferably using broadcast transmission, is disclosed. The second device broadcasts on a second broadcast network a message comprising at least a group identifier common to the set of devices that can access the service and a time reference value corresponding to the emission time of the message, according to a common time reference received by all devices from a first broadcast network. The first device authorizes access to the service only if the group identifier received from the message is the same as the group identifier of the device and if the delay between the measured arrival of the message and its emission time is lower than a threshold.