Just the FACTS: Flexible and Energy Efficient Federated Access Control for the Edge

We present Federated Access ConTrol Support (FACTS) for flexible and energy efficient IoT edge deployments. FACTS is a hybrid approach to access control that couples capability support over MQTT with TLS based security to reduce the power consumption of IoT deployments. Capability systems are lightweight and enable fine-grained access control using cryptographically secure tokens. TLS provides number of security guarantees but is expensive in terms of both time and energy when employed by resource constrained devices at the edge. By combining the two, FACTS enables IoT deployment administrators to decide where and when to use encrypted communication for access control to achieve the best trade-off between data privacy, performance, and energy efficiency. We evaluate FACTS for different deployment scenarios and show that it improves both energy use and performance relative to existing approaches.