Extending MUD Profiles Through an Automated IoT Security Testing Methodology

Defining the intended behaviour of IoT devices is considered as a key aspect to detect and mitigate potential security attacks. In this direction, the Manufacturer Usage Description (MUD) has been recently standardised to reduce the attack surface of a certain device through the definition of access control policies. However, the semantic model is only intended to provide network level restrictions for the communication of such device. In order to increase the expressiveness of this approach, we propose the use of an automated IoT security testing methodology, so that testing results are used to generate augmented MUD profiles, in which additional security aspects are considered. For the enforcement of these profiles, we propose the use of different access control technologies addressing application layer security concerns. Furthermore, the methodology is based on the use of Model-Based Testing (MBT) techniques to automate the generation, design and implementation of security tests. Then, we describe the application of the resulting approach to the Elliptic Curve Diffie-Hellman over COSE (EDHOC) protocol, which represents a standardisation effort to build a lightweight authenticated key exchange protocol for IoT constrained scenarios.