Scalable Security Solution Against Wiretapping for Network Coding Based Priority Encoding Transmission

Network coding is promising to improve the throughput and robustness of video transmission over wireless networks. To address the security issue of network coding based Priority encoding transmission (PET), a special coding design against wiretapping is proposed with hierarchical security. The basic idea is first to randomize partial blocks of each layer and then to encode each layer with inter-layer overlapping coding. The method is characterized by quantifiable security for incremental decoding, and realizes scalability in confidentiality and video transmission, while incurring relatively low computational complexity and bandwidth overhead. A sufficient condition is also presented to design a stronger secure network coded PET system against the known-plaintext attacks. Analysis and evaluation show that the method can be efficient as a new paradigm to secure network coded PET system in realistic applications.