A continuous glucose monitor for wirelessly transmitting data relating to glucose value to a plurality of displays is disclosed, as well as systems and methods for limiting the number of display devices that can connect to a continuous glucose transmitter. In addition, security, including hashing techniques and a changing application key, can be used to provide secure communications between the continuous glucose transmitter and the displays. Also provided is a continuous glucose monitor and techniques for authenticating multiple displays, providing secure data transmissions to multiple displays, and coordinating the interaction of commands and data updates between multiple displays.