Security Enhancement via Dynamic Fountain Code for Wireless Multicast

Harnessing the broadcast nature of wireless channels towards efficient multicast faces very challenging security issues, because reliability assurance for each multicast receiver often result vast frequent retransmissions, thus increasing the chance for eavesdropping. This paper proposes a dynamic fountain code design for security enhancement in wireless multicast against passive eavesdropping. The main features of the proposed scheme include two folds: (i) adaptive encoding structure based on legitimate receivers’ feedback, which aims at degrading the signal quality at the eavesdropper; (ii) benefit the legitimate receivers’ reception as maximally as possible, thus increasing the transmission efficiency compared with the conventional non-adaptive designs. Simulation results are presented to demonstrate that the proposed scheme can effectively decreasing intercepting probability while achieving the higher transmission efficiency, thus facilitating wireless connections in support of multicast services.