February 2014 Summaries

Firesafe, developed by Tom Larkworthy, is a language that compiles state-machine-based protocols into Firebase Security and Rules to help maintain data integrity in distributed real-time applications. The post focuses on preventing item duplication and loss in multiplayer games, problems that can damage virtual economies and create substantial support costs when transactions cannot provide ACID-like guarantees. Because Firebase cannot perform atomic transactions across separate user-account branches or run arbitrary server-side logic, the proposed approach adapts a two-phase commit protocol in which clients advance through carefully constrained states while Firebase rules validate every transition. The protocol ensures an item is either transferred between players or rolled back, supports aborts and recovery if a participant disconnects, and aims to avoid deadlocks without requiring a privileged external server. Firesafe reduces the complexity of encoding these rules, while formal verification is used to identify flaws in the protocol and provide stronger assurance for security-critical database designs.