Multimedia Systems DOI 10.1007/s00530-012-0291-z Match+Guardian: A Secure Peer-to-Peer Trading Card Game Protocol

Abstract In trading card games (TCGs), players create a deck of cards from a subset of all cards in the game to com-pete with other players. While online TCGs currently exist, these typically rely on a client/server architecture and re-quire clients to be connected to the server at all times. In-stead, we propose, analyze and evaluate Match+Guardian (M+G), our secure peer-to-peer protocol for implementing online trading card games. We break down actions com-mon to all TCGs and explain how they can be executed be-tween two players without the need for a third party referee (which usually requires an unbiased server). In each action, the player is either prevented from cheating or if they do cheat, the opponent will be able to prove they have done so. We show these methods are secure and may be shuffled into new styles of TCGs. We then measure moves in a real trad-ing card game to compare to our implementation of M+G and conclude with an evaluation of its performance on the AndroidTM platform, demonstrating that M+G can be used in a peer-to-peer fashion on mobile devices