Interference of overhearing by eavesdropper nodes for secure wireless ad-hoc networks

In ad-hoc networks, data messages are transmitted from a source wireless node to a destination one along a wireless multihop transmission route consisting of a sequence of intermediate wireless nodes. Each intermediate wireless node forwards data messages to its next-hop wireless node. Here, a wireless signal carrying the data message is broadcasted by using an omni directional antenna and it is not difficult for an eavesdropper wireless node to overhear the wireless signal to get the data message. Some researches show that it is useful to transmit a noise wireless signal which collides to the data message wireless signal in order for interfering the overhearing. However, some special devices such as directional antennas and/or high computation power for complicated signal processing are required. For wireless multihop networks with huge number of wireless nodes, small and cheap wireless nodes without such special devices are mandatory for construction of the network. This paper proposes a novel method for interfering the overhearing by the eavesdropper wireless nodes by a routing protocol and a data message transmission protocol with cooperative noise signal transmissions by 1-hop and 2-hop neighbor wireless nodes of each intermediate wireless node. The results of simulation experiments show that the proposed intentional collision method provides enough coverage of noise wireless signals especially by help of part of 2-hop neighbor wireless nodes.