20 International Journal for Modern Trends in Science and Technology Volume: 2 | Issue: 05 | May 2016 | ISSN: 2455-3778 IJMTST Secure & Energy Efficient Scheme against Denial-of-Sleep Attack in WSN Mr. Pavan A C 1 | Mr. P Prasanna 2 1 PG Student, Department of CS&E, P.E.S College of Engineering, Mandya, Karnataka, India 2 Assosiate Professor, Department of CS&E, P.E.S College of Engineering, Mandya, Karnataka, India P Security breaches and energy consumption issues are indispensable in WSN (wireless sensor networks). Considering attacks like Denial-of-Service (DoS) where not only the service is not provided but in addition to that unwanted power is also consumed.“Denial-of-Sleep attack" (type of DoS attack) also results in unnecessary power exhaustion. This paper briefs about how energy consumption could be minimized in WSN by using MAC algorithm in a risk free manner. KEYWORDS: WSN, Key management in Network security, Denial-of-service attack, Denial-of-sleep attack, MAC protocol Copyright © 2015 International Journal for Modern Trends in Science and Technology All rights reserved. I. INTRODUCTION Wireless sensor networks [1] are in continual need where the physical environment requirements are to be converted to readable data. Be it the area of monitoring, heath care or earth sensing like air pollution, WSN sensors are in major use in all such applications. When considering duty-cycle based WSN MAC protocols, the sensor nodes are either in one of the two states namely awake/active and sleep state. These states are switched periodically and they enter sleep mode after certain idle period hence, reducing energy consumption. WSN often encounters various security attacks like:  Wormhole attack  Hello attack  Sybil attacks  Dos attacks One such attacks thus being DOS (denial-of-service).In a DOS attack the legitimate user node is sent certain unwanted data to process sent by the attackers( in manner that data appears to be sent by a genuine user). This leads to not providing the actual service required to the user who requested the service. Common DOS attacks:  Buffer overflow  Ping of death  Smurf attack Denial of sleep [2] is a special type of DOS attack. In denial of sleep attack the sensor nodes are kept awake to consume more energy. An attacker (anti-node) can send fake data packets to legitimate node of unprotected WSNs. Leading to unnecessary transmissions in a repeated manner. If the receiver is unable to judge among the real and the fake node, the receiver will receive and process the data from the anti-node. This keeps the receiver awake as long as the data transmission sustains, thus exhausting the battery of nodes rapid manner. Additionally, the fake node could also send fake ACK in order to give a mask of being genuine .This might lead the legitimate user node to provide all the services to fake node repeatedly. Hence more power consumed unnecessarily. The data to be transmitted is basically encrypted either with keyed symmetric or asymmetric encryption algorithm. Symmetric algorithms are usually preferred in order to avoid the complicated computing and heavy energy consumption. ABSTRACT