Abstract
The Internet of Things is an ever-progressing area. As the number of Internet-connected devices grows, their security grows in complexity. The risk pertaining to the insecurity of these networks is also heightened by the fact that the user's physical environment can be affected by network attacks. The IEEE 802.15.4 wireless network standard provides MAC layer security but does not require MAC packet header encryption, which leaks useful information to an eavesdropper about the network topology. Prior work has demonstrated the use of obfuscation for wireless routing, but there is little existing work targeting energy-efficient topology obfuscation. Our work provides a method for obfuscating the network topology of an IEEE 802.15.4-based network by changing network association. Specifically, we propose the assignment of multiple aliases to each device during the network association phase to give the impression of many devices, wherein the role that a device presents can be further manipulated. We present two algorithms for coordinating aliases with the network authority, both providing multiple MAC addresses per device to degrade a potential attacker's ability to perform reconnaissance attacks. To evaluate our approach, we enhance the corresponding implementation in the popular ns-3 network simulator. We show that the achieved topology obfuscation comes in trade for increased overhead of the association process, both data overhead and latency, a trade-off that we study via simulation. Our ns-3 enhancements will be made publicly available as an open-source ns-3 branch, providing resources for the community and a way to validate and expand up on our work.