Sunil Ghildiyal et al. Int. Journal of Engineering Research and Applications www.ijera.com ISSN: 2248-9622, Vol. 5, Issue 11, (Part - 1) November 2015, pp.86-89 www.ijera.com 86 | Page Denial of Service (DoS) Attacks at Network Layer in WSN Sunil Ghildiyal, Bhupender Singh Rautela, Anupam Semwal Uttaranchal University Dehradun Uttarakhand Graphic Era University Dehradun Uttarakhand Drona College of Mgmt & Tech. Ed. Dehradun Uttarakhand ABSTRACT Recent advancements in technology, tiny size, cost effectiveness have made sensors as a crucial part of real world sensitive applications. These sensor nodes are scattered over an area to monitor the situations like fire, flood and record the data and to forward meaningful data to the center head node for observation, resulting an advance prompt to control the situation. In last decade, WSN have grown significantly in variety of areas and applications, resulted the high, consistent security mechanism. Also, there is variety of attacks on WSN at their different layers of architecture. Though sensor nodes are not capable enough in terms of power, processing etc. but applications based on these sensors demand on-time collection of information or data and then to send same on reliable, secure delivery medium. Small sensors with limited hardware, processing cannot afford traditional security mechanisms to face or sustain the attacks. There is variety of attacks at different layers of WSN architecture to affect sensor‟s roles like signaling, framing, transmission etc. Many Denial of Service (DoS) attacks are identified at each layer of WSN which are purposeful, planned attacks to hamper the availability of service, restricting the sensor node‟s utility for problem solution. In this paper we will focus on the WSN architecture, characteristics, constraints and various types of DoS attacks primarily on physical and data link layer and particularly at network layer in details with some suggestions against attacks. KEYWORDS: Wireless, Sensor, Power, Denial of Service DoS, Attack, Vulnerabilities. I. INTRODUCTION As a result of recent developments in wireless technology polishing, wireless networks are now believed as a reliable architecture medium to deliver communication with major security parameters confidentiality, integrity and availability and non- repudiation. Wireless Sensor Networks consist of less power, less processing capability, small size sensor nodes[1]. Hence, It becomes very tough to raise the capability level of such tiny sensors due to their various constraints. Constraints, associated with sensors are to be considered seriously while designing a secure real world problem solution using WSN. Actually, sensor nodes use RF for messaging, communication and hence use broadcast basically. Since medium is open, it is tedious to protect the broadcast from easy eavesdropping, as injecting can be done very easily over wireless broadcasting. Also, sensor nodes are scattered over a geographical area in physically insecure pattern can be stolen easily, can be tempered physically or replayed or reprogrammed after capturing. Insecure, open deployment of sensor nodes make them to be easily detected for damage purpose[2]. These limited power capacity nodes make WSNs. very weak and paralyzed architecture in front of any intended attack like flooding or replaying etc. One of initial measure against these threats may be authorization access checklist available with them to detect unauthorized or malicious users. II. WSN CHARACTERISTICS For last about two decades, WSNs. have received a lot of interest by the researchers, industry. This is cause of those to be less cost solutions to many real world problem solving applications. Other favoring factors are easy to use, low energy consuming nodes, portability, unattended operation even in no men land with an ability to withstand bad geographical, environmental situations, having dynamic network topology as per situation, faster recovery methods or alternates with sensor node stopping and failures, Mobility of nodes, Heterogeneity of nodes and at all highly scalable in terms of topology and deployment. III. WSN CONSTRAINTS Resource: Sensors are equipped with less capable processors and very low RF linking bandwidth. Of course, It is due to tiny size and low battery. Hence, computational capabilities are also affected by battery and processors. Memory: A sensor node consists of a flash memory and flash RAM. But loading of operating system and other system applications consume much space, leading less space for other tasks and storage. In sensors, flash memory is used for storing downloaded application code. Message Size: As compared to any traditional network, message size of WSN is quite small which results in no concept of segmentation in WSN applications usually. RESEARCH ARTICLE OPEN ACCESS