Security mode can be turn on or off in Arduino IDE. This flag adds Security Command Class in Z-Uno and makes all communications with controller secure. Z-Uno will also try to establish secure communication with devices in Association groups. Security protects communications from reading, modification, replay, authentity substitution attacks. However, it also increases the communication time between nodes by 3 times and battery consumtions. You must upload your sektch and then exclude or reset Z-Uno to apply these changes. A Security enabled Z-Wave Controller must be used in order to use Z-Uno with Security mode on.