SKiMPy: a simple key management protocol for MANETs in emergency and rescue operations

Mobile ad-hoc networks (MANETs) can provide the technical platform for efficient information sharing in emergency and rescue operations. It is important in such operations to prevent eavesdropping, because some the data present on the scene is highly confidential, and to prevent induction of false information. The latter is one of the main threats to a network and could easily lead to network disruption and wrong management decisions. This paper presents a simple and efficient key management protocol, called SKiMPy. SKiMPy allows devices carried by the rescue personnel to agree on a symmetric shared key, used primarily to establish a protected network infrastructure. The key can be used to ensure confidentiality of the data as well. The protocol is designed and optimized for the high dynamicity and density of nodes present in such a scenario. The use of preinstalled certificates mirrors the organized structure of entities involved, and provides an efficient basis for authentication. We have implemented SKiMPy as a plugin for the Optimized Link State Routing Protocol (OLSR). Our evaluation results show that SKiMPy scales linearly with the number of nodes in worst case scenarios.