Analysis of a Homomorphic MAC-based scheme against tag pollution in RLNC-enabled wireless networks

Network Coding-enabled wireless networks are vulnerable to data pollution attacks where adversary nodes inject into the network polluted (i.e. corrupted) packets that prevent the destination nodes from decoding correctly. Even a small proportion of pollution can quickly propagate into other packets via re-coding, occurred at the intermediate nodes, and lead to resource waste. Therefore, during the past few years, several solutions have been proposed to provide resistance against data pollution attacks. One of the most well-known solutions is Homomorphic Message Authentication Code (HMAC). However, HMAC is susceptible to a new type of pollution attacks, called tag pollution attacks, in which a malicious node randomly modifies MAC tags appended at the end of the transmitted packets. To address this issue, we have recently proposed an HMAC-based scheme making use of two types of MAC tags to provide resistance against both data pollution attacks and tag pollution attacks. In this paper, we steer our focus on improving the resistance of our proposed scheme against tag pollution attacks by decreasing the number of MACs. Finally, we analyze the impact of the total number of MACs on the bandwidth overhead of the proposed scheme.