Copyright © 2018 Authors. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. International Journal of Engineering & Technology, 7 (2.32) (2018) 322-326 International Journal of Engineering & Technology Website: www.sciencepubco.com/index.php/IJET Research paper Security Attacks in Wireless Sensor Networks Lalitha Bhagavathi Gurajada 1 , Sai Deepthi Rajaputra 2 , Indira Gogineni 3 , Riaz Shaik 4 1,2,3,4 Department of Computer Science and Engineering, KLEF, Vaddeswaram, India *Corresponding author E-mail: lgurajada@gmail.com Abstract In today’s world, Security is the prime concern for each application. Network security and Computer protection are the serious issues. A broad range of Wireless Sensor Networks (WSNs) applications[1][15] are widely used in military, researches etc. The key subject of computing is to provide network security several types of attacks are increasing day by day. The attacks present in different layers are produced due to the susceptibilities present in the layers. The Seven layers in OSI model are formulated to convey the information from highest layer to lowest layer. Broadcast of data gets modified according to the layer in which it lies. Individually every layer is weak to different types of attacks. This paper models about the different attacks present in each layer of OSI. Keywords: Attacks, Security, Vulnerabilities 1. Introduction The rapid advancement of Computer network technology and internet technology is so quick that makes people aware of network security. Many types of attacks are increasing day by day which made network security an important issue. Wireless sensor networks (WSNs) have a vast field of applications, including environment monitoring, battlefield surveillance and target tracking systems. Seven layers of Open System Interconnection have individual set of functions which performs data to move from source to destination on a network. Every layer gets exploited and has their inherent vulnerabilities. Now a days , this DDoS attack constitutes a major issues and hardest security concern in Internet. Several mechanisms have been implemented to defense the network system from DDOS attacks [2]. DDOS attack targets a server as a victim with huge amount of information by flooding directly or indirectly with lots of zombie computers and prevents legitimate users from accessing. These attacks are launched easily by exploiting the flaws in protocols of internet such as TCP/UDP. Each layer has some vulnerability which ultimately causes attack. This paper gives a survey to understand attacks in different layers of OSI model and DDOS attacks with respect to different layers of OSI Reference Model. 2. Physical layer Attacks 2.1 Defending the Physical Layer: Open System Interconnect comprises of seven layers in that phys- ical layer is at the lowermost of the OSI. This layer is planned to spread the message bit streams via electronic signals, illumina- tions, or else radio broadcasts. The security in this layer must in- clude the connection which is done using wire to connect systems along with the system hardware which supports services. Physical security is one of the oldest features of security. It has the main preference where the protection must begin which depends up on our condition, assets, and budget. This focuses on attackers and thieves and is united with procedural safety along with administra- tive controls which supplies a comprehensive view of security. DDoS attacks in the Physical layer are destruction, obstruction, exploitation, or break down of physical assets, The Impacts are the Physical resources will become impassive and they need to be repaired to increase their availability. 2.2 Attacking the Physical Layer: Control is the significant feature for security in the physical layer. If any person attains physical control over the system, it generally holds to control a device’s performance [10]. That’s why physical security plays a noteworthy role in worldwide security. Here we have numerous forecasts that physical security can be challenged by (for example: stealing data, lock picking). 2.2.1 Stealing Data: This Physical layer attack is the major effortless aspect for a mali- cious insider to effort, since they previously contain an approach to the system. State sponsored industries might obtain the profit from the trade secrets and insider information. Some of these at- tacks have become informal as progressions in electronics and optoelectronics contain intelligence work, interception, and infor-