Confidential Network Coding: Physical Layer vs. Network Layer

In all kind of information exchange, security is essential. One protection goal that has to be enforced is confidentiality. In state-of-the-art protocols, messages are encrypted before they are transmitted to ensure their confidentiality. However, incorporating novel technologies like network coding allows for more efficient solutions. Within this article, we compare different solutions for confidential communication by means of network coding at physical layer and at network layer. We discuss security, efficiency, and computational complexity of these approaches. The results allow to draw conclusions about the choice of a suited communication scheme depending on the system model and the relevant parameters.