AuCRB: An Efficient Mechanism to Provide Availability, Reliability and Authentication for Multihop Broadcasting in Wireless Networks

This paper proposes a reliable and secure broadcast protocol for ad hoc wireless networks. Since coding and security compete for the same resources, we jointly solve for reliability, availability and integrity for a broadcast scenario. Packets sent by the source node would travel in a hop-by-hop fashion to the other nodes. Hence, it is critical to reduce the number of transmissions and latency. We assume Byzantine attacks in which the adversary can drop (or modify) legitimate packets and inject its own packets via several insider nodes. We require that the source data is reached to all legitimate nodes in the presence of any number of colluding Byzantine attackers as long as the legitimate nodes are connected. We also require that each receiver node in the network to be equipped with a mechanism to verify the source node and the integrity of the received packets using limited cryptographic primitives. It is essential that every node receiving a malicious packet immediately filters it out and uses only the legitimate ones for forwarding to the next hop and decoding. Designing a broadcasting mechanism that satisfies all the above requirements is a very challenging problem. We develop an authentication scheme, using a reliable and energy-efficient broadcasting protocol called Collaborative Rateless Broadcast (CRBcast) and limited cryptographic primitives. On contrary to the previous schemes, our scheme is resilient with respect to Byzantine failures as well as routing and flooding attacks and protocol exploits. Moreover, we compared our scheme with the previously proposed broadcast authentication schemes and showed that our scheme outperforms them in terms of efficiency. This is a crucial improvement over the previous schemes that ensure availability by flooding, but with very large communication overhead and latency.