A system, comprising: a plurality of terminals (105A, 105B); a gateway computer, programmed to: distribute an encryption key, in a unicast mode, to the plurality of terminals (105A, 105B); receive traffic data from a remote computer; and multicast the received traffic data to the plurality of terminals (105A, 105B) by: encrypting the received traffic data with the encryption key; and multicasting the received traffic data encrypted with the encryption key to the plurality of terminals (105A, 105B); wherein each of the plurality of terminals (105A, 105B) include: a terrestrial communication interface; a satellite communication interface, for satellite communication with the gateway computer via a satellite link, wherein the terrestrial and satellite communication interfaces (120, 115) are configured to communicate traffic data; and a computer communicatively linked to the terrestrial and satellite communication interfaces (120,115), wherein the computer determines that encrypted multicast data is received, wherein the computer executes instructions, to determine that the traffic data, communicated via the terrestrial communication interface, exceeds a threshold; and based on the determination, route at least a portion of traffic data via the satellite communication interface in accordance with a traffic data load-balancing scheme. a plurality of terminals (105A, 105B); a gateway computer, programmed to: distribute an encryption key, in a unicast mode, to the plurality of terminals (105A, 105B); receive traffic data from a remote computer; and multicast the received traffic data to the plurality of terminals (105A, 105B) by: encrypting the received traffic data with the encryption key; and multicasting the received traffic data encrypted with the encryption key to the plurality of terminals (105A, 105B); distribute an encryption key, in a unicast mode, to the plurality of terminals (105A, 105B); receive traffic data from a remote computer; and multicast the received traffic data to the plurality of terminals (105A, 105B) by: encrypting the received traffic data with the encryption key; and multicasting the received traffic data encrypted with the encryption key encrypting the received traffic data with the encryption key; and multicasting the received traffic data encrypted with the encryption key to the plurality of terminals (105A, 105B); wherein each of the plurality of terminals (105A, 105B) include: a terrestrial communication interface; a satellite communication interface, for satellite communication with the gateway computer via a satellite link, wherein the terrestrial and satellite communication interfaces (120, 115) are configured to communicate traffic data; and a computer communicatively linked to the terrestrial and satellite a terrestrial communication interface; a satellite communication interface, for satellite communication with the gateway computer via a satellite link, wherein the terrestrial and satellite communication interfaces (120, 115) are configured to communicate traffic data; and a computer communicatively linked to the terrestrial and satellite communication interfaces (120,115), wherein the computer determines that encrypted multicast data is received, wherein the computer executes instructions, to determine that the traffic data, communicated via the terrestrial communication interface, exceeds a threshold; and based on the determination, route at least a portion of traffic data via the satellite communication interface in accordance with a traffic data load-balancing scheme. determine that the traffic data, communicated via the terrestrial communication interface, exceeds a threshold; and based on the determination, route at least a portion of traffic data via the satellite communication interface in accordance with a traffic data load-balancing scheme.