Developing a Secure LowCost Radon Monitoring System Radon gas has been declared a human carcinogen by the United States Environmental Protection Agency (USEPA) and the International Agency for Research on Cancer (IARC). Several studies carried out in Spain highlighted the high radon concentrations in several regions, with Galicia (northwestern Spain) being one of the regions with the highest radon concentrations. The objective of this work was to create a safe and lowcost radon monitoring and alert system, based on open source technologies. To achieve this objective, the system uses devices, a collection of sensors with a processing unit and a communication module, and a backend, responsible for managing all the information, predicting radon levels and issuing alerts using open source technologies. Security is one of the largest challenges for the internet of things, and it is utterly important in the current scenario, given that high radon concentrations pose a health risk. For this reason, this work focuses on securing the entire endtoend communication path to avoid data forging. The results of this work indicate that the development of a lowcost, yet secured, radon monitoring system is feasible, allowing one to create a network of sensors that can help mitigate the health hazards that high radon concentrations pose.

A Raspberry Pi Mesh Sensor Network for Portable Perimeter Security Wireless sensor networks play an important role for perimeter monitoring in remote environments. While commercial wireless sensor networks for providing audiovisual monitoring exist, they are often expensive to deploy. In this paper, we describe and implement a wireless mesh network consisting of inexpensive batteryoperated Raspberry Pi nodes. The choice of the Raspberry Pi enables the construction of costeffective sensor nodes that are extendable and expendable. We conduct a series of test to illustrate the efficacy of our network in a building monitoring use case. Our nodes can be built for as little as 49.00 per node and is capable of nodetonode transmission of up to 50 feet. Custom sleep states enable battery life to last 14 hours on 4 AA batteries. Our results support our thesis that an allPi mesh sensor is capable of providing portable perimeter security.