Abstract: Security is one of the most important issues that have attracted a lot of research and development effort in past few years. In multi-hop wireless ad hoc network link error and malicious packet dropping are two sources for packet losses. Whether the losses are caused by link errors only, or by the combined effect of link errors and malicious drop are to be identified, can be known by observing a sequence of packet losses in the network. But in the insider-attack case, whereby malicious nodes that are part of the route exploit their knowledge of the communication context to selectively drop a small amount of packets critical to the network performance. Conventional algorithms that are based on detecting the packet loss rate cannot achieve satisfactory detection accuracy because the packet dropping rate in this case is comparable to the channel error rate. Hence to improve the detection accuracy, the correlations between lost packets is identified. The technique called Homomorphic linear authenticator (HLA) based public auditing architecture is developed that allows the detector to verify the truthfulness of the packet loss information reported by nodes. This technique provides privacy preserving, collusion proof, and incurs low communication and storage overheads. A packet-block based mechanism is also proposed, to reduce the computation overhead of the baseline scheme, which allows one to trade detection accuracy for lower computation complexity.

Keywords: Homomorphic linear authenticator, Auditing, AES.