Withthe advent of a new era in computation and informationtechnology, Internet of things (IoT) is building block ofubiquitous computing1 and billionsand billions of Things are connected to the Internet2. Life has happen to besmarter due to the Internet of Things (IoT) anytime, anywhere, anyplace andanyone access3. It provide communication between machine-to-machine (M2M)  without human interference4 and human-to-human(H2H), human-to-thing (H2T), thing-to-thing (T2T) or thing-to-things (T2Ts)5.IoT networks dynamic, heterogeneous and distributed nature. The IoT include concepts such asWireless Sensor Networks (WSN), Machine-to-Machine (M2M) communications and Lowpower Wireless Personal Area Networks (LoWPAN), or technologies such asRadio-Frequency Identification (RFID)6.

 The IoT technology has full of devicescomprising sensors, actuators, and data processors ,with this computationalresources it will enable the sensing, capturing, collection, and processing ofreal-time data from billions of connected devices, and can be envisaged toserve many different applications including environmental monitoring,industrial applications, business, and human-centric pervasive applicationssuch as Smarter cities forincreasing security, green energy, and intelligent parks; intelligent transportation system forbuilding smarter infrastructure and toward smart logistics systems; agriculture, smartgrids for intelligent monitoring, control and efficient delivery of electricityto consumers; smart healthcare systems;4 The key requirements for IoTarchitecture are Resource Control, Energy Awareness, Quality of Service, Interoperability,Interference Management, Security 100. The IoT challenging issues foraccommodating the trillion of IoT devices are Interoperability, Scalability, Flexibility,Energy Efficiency, Mobility Management, Security7. Securityis crusial one while in some of IoT application such as health care systems,Industrial applications. In general, Information Security goals are related tothe act of ensure information protection in three different aspects: Privacy,Integrity and Availability and network security in terms of confidentiality,authentication.This paper focus on security issues5 relatedto security and privacy of IoT network.