The ICG NxtLink series of Iridium systems delivers an external secure voice and data option to permit air-to ground and ground-to-air secure capabilities. ICG has tested and successfully proven reliable secure voice and data services using the General Dynamics Sectera Wireline terminal. The device uses the new Future Narrow Band Data Transmission (FNBDT) protocol which permits high quality secure voice over a 2400 bps transmission channel via the Iridium network. The unit has been tested with both “Type I” and “Exportable” encryption algorithms installed in the device. Through use of a standard 2-Wire telephone handset connected to the secure device, a secure connection can be established to an equivalent ground side device, permitting a secure conversation or secure data transmission via an inexpensive Iridium channel.