Wireless sensor networks (WSN) have a set of algorithms and protocols with self-establishing capabilities. These sensors work with every other to sense some physical phenomenon after which the information gather is processed to get relevant outcomes. These sensor nodes can calculate, sense, and assemble particulars from the atmospheres and based on some neighborhood decision process, they are able to transmit the sensed records to the person. The battery is the main electricity supply in a sensor node and secondary power supply that harvests strength from the atmospheres together with solar panels may be added to the node depending on the appropriateness of the atmospheres where the sensor will be diffuse. Clustering is the technique which performs the grouping of similar nodes and then starts communicating into the clusters. Security can be achieved by encrypting and decrypting the data and make them unable to read that from the malicious users. Cryptography is the useful technique which contains symmetric and asymmetric methods. In this paper we study about WSN and its application or various attacks which exist in the sensor network in the middle of paper we discuss various existing technique and it’s working. Various attacks are performed in this network such as passive and active attacks or insider and outsider attacks. The wirelessly network always required security in the form of data integrity, confidentiality, authenticity and etc.

WSN; attacks; security; security issues;

[1] NM. Nair, JS. Terence, "Survey On Distributed Data Storage Schemes In Wireless Sensor Networks", Indian Journal of Computer Science and Engineering (IJCSE), Vol.4, No.6, pp.1-6, 2014.
[2] Jennifer Yick, Biswanath Mukherjee, Dipak Ghosal, “Wireless sensor network survey”, Science direct, Vol.52, Issue.12, pp.2292–2330, 2008.
[3] AS. Mandloi, V. Choudhary, "An Efficient Clustering Technique for Deterministically Deployed Wireless Sensor Networks", International Journal of Scientific Research in Network Security and Communication, Vol.1, Issue.1, pp.6-10, 2013.
[4] Sanchita Gupta, Pooja Saini, "Modified Pairwise Key Pre-distribution Scheme with Deployment Knowledge in Wireless Sensor Network", International Journal of Scientific Research in Network Security and Communication, Vol.1, Issue.2, pp.21-23, 2013.
[5] N. Meenaksi, P. Rodrigues, "Tsunami Detection and forewarning system using Wireless Sensor Network - a Survey", International Journal of Computer Sciences and Engineering, Vol.2, Issue.3, pp.76-79, 2014.
[6] Chanchal Yadav, SS. Hegde, NC. Anjana, Sandeep Kumar, “Security Techniques in Wireless Sensor Networks : A Survey”, International Journal of Advanced Research in Computer and Communication Engineering, Vol.4, Issue.4, pp.289-295, 2015.
[7] Jaydip Sen, “A Survey on Wireless Sensor Network Security”, International Journal of Communication Networks and Information Security, Vol.1, No.2, pp.1-16, 2009.
[8] Xiaoliang Menga, Xiaochuan Shia, Zi Wangb, Shuang Wua, Chenglin Lia, “A grid-based reliable routing protocol for wireless sensor networks with randomly distributed clusters”,elsevier, Vol.51, NO.11, pp.47–61, 2016.
[9] Hacene fouchal, javier biesa, elena romero, alvaro araujo, octavio nieto taladrez, “a security scheme for wireless sensor networks”, 2016 IEEE Global Communications Conference (GLOBECOM), Washington, pp.1-5,2016.
[10] Gagandeep Kaur, Deepali, Rekha Kalra,“Improvement and analys security of WSN from passive attack”, 2016 5th International Conference on Reliability, Infocom Technologies and Optimization (Trends and Future Directions) (ICRITO), Noida, pp.420-425, 2016.
[11] Janusz Furtak, Zbigniew Zieliński, Jan Chudzikiewicz, “Security techniques for the WSN link layer within military IoT”, 2016 IEEE 3rd World Forum on Internet of Things (WF-IoT), Reston, pp.233-238, 2016
[12] Mauricio Tellez, Samy El-Tawab, M. Hossain Heydari, “IoT security attacks using reverse engineering methods on WSN applications”, 2016 IEEE 3rd World Forum on Internet of Things (WF-IoT), Reston, pp.182-187, 2016.
[13] pooja m. shukre, divya chirayil, “enhancement in didrip protocol to securely disseminate data in wireless sensor network sign in or purchase”, 2016 International Conference on Communication and Electronics Systems (ICCES), Coimbatore, pp.1-4, 2016.
[14] MU Aftab, Omair Ashraf, Muhammad Irfan, Muhammad Majid, Amna Nisar, MA. Habib, “A Review Study of Wireless Sensor Networks and Its Security”, Communication Network, Vol.7, No.4 , pp.172-179, 2015.
[15] Biji Nair, C. Mala,“Analysis of ECC for application specific WSN security”, 2015 IEEE International Conference on Computational Intelligence and Computing Research (ICCIC), Madurai, pp.1-6, 2015.