Constrained Random Routing Mechanism for Source Privacy Protection in WSNs in NS2

In wireless sensor networks, it is a typical threat to source privacy that an attacker performs backtracing strategy to locate source nodes by analyzing transmission paths. With the popularity of the Internet of Things in recent years, source privacy protection has attracted a lot of attentions. In order to mitigate this threat, many proposals show their merits. However, they fail to get the tradeoff between multipath transmission and transmission cost. In this paper, we propose a constrained random routing mechanism, which can constantly change routing next-hop instead of a relative fixed route so that attackers cannot analyze routing and trace back to source nodes. First, we design a specific selection domain which is located around the sending node according to the dangerous distance and the wireless communication range. Then sending nodes calculate the selected weights of the candidate nodes according to their offset angles in this domain. Finally, the selected weights help to decide which node will become the next hop. In this way, attackers would be confused by the constantly changing paths. The simulation results prove that our proposal can achieve high routing efficiency in multi-path transmission, while only introducing a controllable energy consumption, end-to-end delay and redundant paths.