Infrastructure networks like power systems can be suitable media for data communication, either as broadband which it is called BPL (broadband over power line) or narrowband which it is known PLC (power line carrier). Also it is claimed that security robustness of complex communication networks like the Internet to an intentional attack (that brings down network nodes) depends on their topology. In this article, we investigate the dependency of BPL data communication network (as a kind of communication networks) security robustness against the intentional attack to the topology of power system that has been ignored in past studies. The analysis is based on graph theory. We derived two security criteria (biggest cluster size and cluster diameter) for our assessment. It is shown that by changing the structure of power system, the security robustness of the data communication network will be varied. This study brightens the way for future layout development of combined data communication networks with different infrastructures.