31-08-2017, 01:36 PM
Advances in ad hoc wireless network routing protocols have run to keep pace with the demands of a less structured, mobile and dynamic routing environment. Along with the rapid development of these protocols, new forms of attacks and exploitations have begun to pose security issues in data transmission. Current ad-hoc mobile network protocols allow the presence of hidden channels, which create a secret transfer of information through a secure network policy. In this paper we present several methods of data coding and undetectable communication transfer between nodes in the Dynamic Source Routing (DSR) protocol. The DSR protocol uses source routing instead of hop-by-hop routing used by most other protocols, which eliminates the need for frequent route advertisements and neighbor detection packets. Unlike hidden channels observed in other protocols, such as the AODV (Ad-hoc On-Demand Distance Vector) protocol, due to promiscuous listening and buffering via intermediate node paths, a destination node in a DSR does not always receive routing packets sent from a source sender node. Therefore, we present several methods of covert communication that guarantee the secret delivery of information. We also explored methods of detecting and preventing this manipulation of network resources, and provided a framework of comparison for protocol capability for covert channels versus other network routing protocols. The comparison shows that hidden channels in DSR are sometimes impossible to detect; however, measures such as aggressive cache cleaning, neighborhood clocks, and digital signatures in forwarded request packets can provide a security backdrop against malicious users.