Detecting the Capacitance-Based Gamepad for Protecting Mobile Game Fairness

Mobile game has become a big industry, whose success heavily depends on the game fairness. Recently, a new type of physical cheating instrument, the capacitance-based gamepad (CBG), has been wildly used in popular mobile games. CBG players can obtain an unfairly overwhelming control advantage (e.g., more sensitive clicking and sliding) over benign players. Moreover, as a physical peripheral, CBG is completely transparent to the game application and the underlying system. This makes it inherently immune to existing cheating detection techniques. In this study, by disassembling the CBG device, we find a leverageable physical limitation that the distributions of generated clicking and sliding are more concentrated around a limited area or a boundary respectively. Accordingly, a novel method is proposed to detect the CBG-based cheating. Specifically, to detect the CBG clicking, we employ the entropy to measure the uncertainty of the clicking coordinates; and to detect the CBG sliding, we introduce the convex hull identification algorithm to recognize the potential sliding boundary. We have applied our detection method to four popular mobile games. The evaluation results demonstrate the effectiveness of the proposed method. We believe that the proposed method can be easily adopted by the manufacturers to fight against the CBG-based cheating and protect the game fairness.