 The radio protocol has been criticised for its proprietary encryption, including a petition encouraging a change to an open protocol.It has been argued that encryption increases processing time and contradicts the goal to increase aviation safety due to a closed monopoly market, because an open protocol could enable third party manufacturers to develop compatible devices, spreading the use of interoperable traffic advisory systems.FLARM Technology opposed these claims as published on the petition page and published a white paper explaining the design of the system.