DisasChat: An End-to-End Encrypted Off-Grid LoRa-Based Smartphone Communication System for Disaster and Crisis Scenarios

Large-scale disasters like earthquakes, storms, and floods often severely damage the existing infrastructures for telecommunication and make them unavailable. This prevents the otherwise seamless flow of information, toughening the job of rescue and relief. In such a scenario, the need for rapidly deployable network solutions becomes important for restoring connectivity and providing assistance to the people and rescuers to coordinate their relief efforts. In this work, we propose a novel strategy for long-range communication based on the LoRa technology for such post-disaster situations where resources are scarce. A decentralized, low-power, secure, and robust communication system is proposed that can be helpful in challenging scenarios. We implemented and tested our system named Disaschat, which also protects the privacy of its users with end-to-end encryption while enabling long-range communication efficiently. We demonstrated the system’s feasibility by sending text messages from one Smartphone to another using our proposed system and display our findings.