Superluminal Signaling and Time Machine

Recently, time machine becomes a hot topic in the physics community[1-7]. But it is still unclear whether or not time machine does exist. In this short paper, we will analyze the possible relation between superluminal signaling and time machine. It will be shown that the realization of superluminal signaling will exclude the existence of time machine, or vice versa. Furthermore, we denote that the usual proof for the possible existence of time machine may fail due to ignoring the limitation of relativity.