Security-Enhanced Wireless Multicast via Adaptive Fountain Codes over Distributed Caching Network

With the kept-increasing interconnecting capability over Internet, distributed caching techniques can be applied for secure data storage. In particular, the entire data file of interests is stored in multiple distributed servers with each caching only a random part of the file. In this scenario, an attacker needs to intrude multiple servers to steal the whole file. If the legitimate receivers typically use mobile terminals such as smart phones, the attacker inclines to eavesdrop on open wireless channels to steal the file more easily. To protect the data from overheard by eavesdroppers, we propose a dynamic fountain coding scheme for wireless access point, adapting to the cached contents in the current server and data-reception states. Our proposal focuses on the challenging wireless multicast transmission as it costs at more redundancy transmissions for error control. Besides the adaptive encoding design, we design an efficient server selection strategy to decrease the transmission delay and reduce the probability of successfully overhearing by eavesdroppers. The simulation results show that our proposed scheme can efficiently achieve low eavesdropping probability and high transmission efficiency with a bit accredited complexity for distributed wireless caching network.