LS-LEACH: A New Secure and Energy Efficient Routing Protocol for Wireless Sensor Networks Muneer Alshowkan, Khaled Elleithy, Hussain AlHassan Department of Computer Science and Engineering University of Bridgeport Bridgeport, USA {malshowk, elleithy, halhassa} @bridgeport.edu Abstract—Wireless sensor networks are facing many challenges such as the limited resource in processing power, storage and energy. The limited energy resource is one of the main challenges facing the security in such networks. This paper aims to improve the current security mechanisms in wireless sensor networks as well as reducing power consumption. LEACH protocol provides an energy routing protocol. However, it doesn’t cover the security problems. Alternatively, this paper aims to provide an improved secure and more energy efficient routing protocol called LS-LEACH (Lightweight Secure LEACH). Authentication algorithm is integrated to assure data integrity, authenticity and availability. Furthermore, this paper shows the improvement over LEACH protocol that makes it secure and how to make it more energy efficient to reduce the effect of the overhead energy consumption from the added security measures. Keywords—attacks; wireless sensor; energy efficient; sensor security I. INTRODUCTION Wireless sensor networks form an infrastructureless wireless network where nodes are independent and self- organizing. Such networks provide an emerging technology that solve some of the environmental and social challenges by monitoring and collecting data related to the targeted applications [1, 2]. Notably, nodes perform a specific job by sensing the intended physical parameter. The key factor of using wireless sensors is because they have interesting characteristics such as low-power consumption and low cost. Many applications of wireless sensor networks are designed to observe a variety of environments and collect data. The data is projected in different classifications based on their intended application. Applications of the aforementioned are related to nature, governments, and individuals. However, assuring data confidentiality, authenticity, availability, and integrity must be maintained. Security is one of the challenging aspects in wireless networks because it has effect on the sensors resource due to the very limited resources in the wireless sensors [3, 4]. Mobile and ad-hoc networks employ conventional security. Due to wireless sensor limitations it is hard to employ conventional security measures on wireless sensors networks. For example, it is inefficient to employ SSL protocol. SSL protocol requires a high amount of energy which is inefficient in wireless sensor networks. [5, 6]. In wireless sensor networks, there are many applications that require a high security level. For instance, military and health care applications. Such applications require maximum security. However, an increase in security consumes more resources [7]. When more resources are consumed it can negatively impact the lifespan of the network. Wireless sensors should have the maximum security with minimal power consumption to assure secure communication [8-10]. In the literature, many energy efficient protocols were proposed. LEACH protocol (Low-Energy Adaptive Clustering Hierarchy) [11] shown in Fig. 1 is a self-organizing and based on clustering hierarchy which is able to outperform the MTE (Minimum Transmission Energy) protocol by 8 times. Fig. 1. LEAH Clustering Hierarchy In this paper, we provide security measures to LEACH protocol after indicating the source and limitation of nodes. Also, we develop security measures to protect wireless sensors and the communications from possible attacks without compromising the network performance. For instance, securing LEACH protocol against denial of service attacks while maintaining its performance. Furthermore, the protocol assures that only the authenticated nodes are allowed to join and communicated in the network. At the other hand, we mitigate the overhead cost from the security measures applied to avoid compromising the network performance.