CovLBCG: A Covert Communication Framework Using Live Broadcast Bullet Comment Game

Covert communication has numerous applications across various domains, including the military, the Internet of Things, blockchain, and beyond. Among these, the covert communication method that exploits the unique cover types inherent in single-player games has garnered substantial attention from researchers. However, existing methods are unsuitable for the current social media such as audio and video and traditional blogs, poor interactivity, and player communication content can easily cause unnatural behavior of game characters. For this reason, a covert communication framework based on live broadcast bullet comment games is proposed. Within the framework, the sender initially applies arithmetic encoding to compress the confidential message. Then, the processed message is transformed into the content and time attributes of the bullet comment, adhering to the game's rules. Finally, these bullet comments are sent to the designated live broadcast game room. The receiver extracts the bullet comments sent by the sending party in real time and converts them into confident messages. As a representative of the framework, ${\mathit{Plants vs. Zombies}}$, is utilized as an example. Experimental results have identified the optimal method for sending game bullet comments, balancing detection resistance and transmission speed. The proposed approach offers notable advantages in security interactivity and transmission speed, with 4.1 times faster than existing processes.