Resource Integrity Vulnerabilities and Protections in RPG Games: A Case Study of Elancia

Abstract

The rapid advancement of network and internet technologies has profoundly impacted the online gaming industry, particularly in the domain of Massively Multiplayer Online Role-Playing Games (MMORPGs). These games, which allow players to interact in a shared virtual world, have witnessed a surge in popularity. However, the rise of cheating and malicious activities facilitated by rogue users and cheat developers poses a significant threat to the gaming industry and the experiences of fair-playing users. In this study, we analyzed the client resource files of the MMORPG Elancia, developed by Nexon, to understand their structure. Our findings revealed that critical game resource files, including graphics, music, and character settings, could be modified by unauthorized users, with the altered content taking effect during gameplay. To address this vulnerability, we proposed both client-side and server-side integrity verification methods for client resource files. On the client side, we suggested verifying the integrity of resource files by comparing their Merkle Root with the Merkle Root stored on the server. On the server side, we proposed a cloud gaming environment where resource files are not stored on the client; instead, the client sends input to the server, which renders the results and transmits them back to the client. Additionally, the server verifies client inputs and events, storing the results for further validation. To validate the proposed methods, we customized Minecraft’s Forge mod to evaluate the performance of our approaches. The results underscore the critical role of client-side file integrity in maintaining game security and highlight the potential impact of robust protection measures on safeguarding the gaming ecosystem.