Secure opportunistic routing protocols: methods, models, and classification

Addressing communication reliability and security has always been of significant importance in wireless networks. Opportunistic routing(OR) protocols comprise a promising area of research that aims to improve the reliability of communications, particularly in lossy networks. The main concept behind OR protocols is to utilize the broadcast nature of the wireless medium and determine a group of neighboring node candidates, known as candidate set, to collaboratively forward packets towards the destination using a candidate coordination approach. However, similar to traditional routing protocols, OR protocols operate poorly in the presence of malicious nodes and attackers. Therefore, researchers have designed and developed a number of security enhancements, considering the specific characteristics of such protocols. In this paper, following a brief overview on OR protocols, we examine, classify, and compare the different categories of security approaches proposed for OR protocols. More precisely, we divide security-related OR protocols into three categories, including trust-based approaches, game-theory-oriented solutions, and other related protocols. Furthermore, the most significant algorithms of each category are investigated as case studies. Finally, a comparison of different protocols is presented considering the main features, advantages, and shortcomings of each protocol.