LinkA: A Link Layer Anonymization Method Based on Bloom Filter for Authenticated IoT Devices

In point-to-point communication channels, an anonymization mechanism is necessary for a data link layer because link layer IDs such as MAC addresses can reveal further private information about communicating devices, which may threaten cyber security. Previous mechanisms based on heavy cryptographic operations are not suitable for link layer that needs to immediately accept or drop frames, particularly in resource-constrained IoT. In this paper, we study a link layer anonymization method that functions efficiently for the current existing systems using 48-bit or 64-bit MAC addresses. Our method called LinkA is based on the Bloom Filter and the use of pre-authenticated structure regarding MAC addresses. LinkA can efficiently frustrate passive adversaries to distinguish unicast from multicast frames. We also implement and analyze LinkA.