Characterization of Band Codes for Pollution-Resilient Peer-to-Peer Video Streaming

We provide a comprehensive characterization of Band Codes (BC) as a resilient-by-design solution to pollution attacks in Network Coding (NC) based peer-to-peer live video streaming. Consider one malicious node injecting bogus coded packets into the network: the recombinations at the nodes generate an avalanche of novel coded bogus packets. Therefore, the malicious node can cripple the communication by injecting in the network only a handful polluted packets. Pollution attacks are typically addressed by identifying and isolating the malicious nodes from the network. Pollution detection is however not straightforward in NC as the nodes exchange coded packets. Similarly, malicious nodes identification is complicated by the ambiguity between malicious nodes and nodes that have involuntarily relayed polluted packets. This paper addresses pollution attacks through a radically different approach which relies on BC. BC are a family of rateless codes originally designed for controlling the NC decoding complexity in mobile applications. Here we exploit BC for the totally different purpose of recombining the packets at the nodes so to avoid that the pollution propagates by adaptively adjusting the coding parameters. Our streaming experiments show that BC curb the propagation of the pollution and restore the quality of the distributed video stream.