On Study of Physical-Layer Attack Detection for Large Volumes of Data

We consider Byzantine attack detection for Gaussian two-way relay network which carries large volumes of data. Two source nodes communicate with each other with the help of an amplify-and-forward relay which may perform Byzantine attacks by forwarding altered symbols to the sources. For simple investigating the detectability of attacks conducted in Gaussian channels, we focus on the multi-access (MA) channel of the network, while assuming the broadcasting (BC) channel is noiseless. Upon such model, we propose a attack detection scheme implemented in the sources upon physical-layer observations. Specifically, we consider a open wireless propagation environment that allows the symbols, forwarded by the relay, to go through a continuous channel and arrive to the sources. With the observations of the source, we develop a detection scheme for the source by comparing the joint empirical distribution of its received and transmitted signals with the known channel statistics. The main contribution of this paper is to prove that for the Gaussian MA channel, using large volumes of data, the proposed detection scheme can detect arbitrary independent identically distributed (i.i.d.) attacks that allows the stochastic distributions of altered symbols to follow arbitrary distributions. No pre-shared secret or secret transmission is needed for the detection.