The invention concerns a medical assembly which insures a secured communication between a medical device (like a insulin pump) and its remote control which manages the medical device. To this effect, said assembly use an external microcontroller (MCU) which contains the secured data and uses a cryptographic mechanism to communicate with the medical device. One single external microcontroller (MCU) is paired with only one medical device in such a way the patient can change several times of remote device although aware that the remote device, in which said external protected MCU is inserted, is the single remote device paired with the medical device. In said assembly, said medical device and said external microcontroller (MCU) comprise secured memories which contain the wireless communication configuration in such a way the devices know in advance the good configuration.