Fundamental limits of caching in D2D networks with secure delivery

We study the problem of secure transmission over a caching D2D network. In this model, end users can prefetch a part of popular contents in their local cache. Users make arbitrary requests from the library of available files and interact with each other to deliver requested contents from the local cache to jointly satisfy their demands. The transmission between the users is wiretapped by an external eavesdropper from whom the communication needs to be kept secret. For this model, by exploiting the flexibility offered by the local cache storage, we establish a coding scheme that not only conforms to the demands of all users but also delivers the contents securely. In comparison to the insecure caching schemes, the coding scheme that we develop in this work illustrates that for large number of files and users, the loss incurred due to the imposed secrecy constraints is insignificant. We illustrate our result with the help of some examples.