ContextNet is a middleware that aims at provisioning context services for large-scale IoT applications such as remote monitoring and coordination of mobile entities. Mobile Hub is a middleware that runs on Android systems and connects simpler IoT devices to the internet through short-range technologies such as BLE. The use and importance of IoT systems have increased significantly in recent years, and data breaches or malicious control of intelligent devices could cause great damages, both economically and physically. This project aims at implementing security features to BLE communications, ensuring authentication, authorization, integrity, and confidentiality to data exchanged between the Mobile Hub and an IoT device. It also has the goal of creating a VPN connection between the Mobile Hub and the ContextNet core through a secure tunnel. The implementation in BLE communication was achieved successfully using security mechanisms such as OTP, HMAC, and symmetric stream encryption. However, some difficulties were found while implementing the VPN communication that made it impossible to finish it within the project deadline. Performance tests were made, showing the processing costs involved in this solution, as well as possible improvements and optimizations. Although incomplete, the architecture developed in this project already guarantees a great increase in the security level of these middlewares, serving as a base to similar IoT applications.