One of the most vexing problems in wireless sensor network security is the node Clone attack. In this attack, an adversary breaks into a sensor node, reprograms it, and inserts several copies of the node back into the sensor network. Cloning gives the adversary an easy way to build an army of malicious nodes that can cripple the sensor network. A few distributed solutions to address this fundamental problem have been recently proposed. However, these solutions are not satisfactory. Therefore first, the desirable properties of a distributed mechanism for the detection of node Clone attacks have been analyzed. Second, the known solutions for this problem do not completely meet our requirements. Third, a new self healing, Randomized, Efficient, and Distributed (RED) protocol for the detection of node Clone attacks has been proposed, and it satisfies the intended requirements. Index Terms: clone attack, RED, witness distribution, oblivious, performance, WSN. I. Introduction Wireless Sensor Networks (WSN) are developing as both a vital new domain in the IT environment and a hot research including system design, networking, distributed algorithms, programming models, data management, security and social components. Wireless sensor networks are rapidly picking up the popularity as they are potentially low cost solutions. The fundamental thought of sensor network is to scatter minor sensing gadgets over a particular geographic zone for some specific purposes like target tracking, surveillance, environmental screening and so on. These tiny devices are equipped for sensing a few progressions of parameters and communicating with different units. A wireless sensor network (WSN) is a remote system comprising of an extensive number of geologically dispersed sensor nodes. These sensor nodes could be effectively conveyed at vital districts easily at a low cost. Sensor nodes collaborate with one another to screen physical or ecological conditions, for example, temperature, sound, picture, vibration, weight, movement or contaminations with the assistance of different sorts of sensors. However, while much consideration is constantly paid to the routing strategies and wireless sensor network modeling, the security issues are yet to receive extensive focus. Essentially the utilization of any effective security conspire in wireless sensor systems is encouraged by the span of sensors, the processing power, memory and kind of functions anticipated from the sensors. Sensor networks are not universally traditional computing devices; subsequently the existing security models and strategies are lacking to run with them. In sensors, the geographic dissemination of the units allows an attacker to physically have control of nodes and study mystery key material, or to capture messages. The hierarchical nature of sensor networks and their route maintenance protocols permit the attacker to confirm where the root node is placed. WSNs are picking up interest in the research community due to their unique qualities. WSNs are very little watched. Consequently it is effectively conceivable for an assaulter to catch a hub physically, altering its code and getting private data like cryptographic keys. Wireless medium is inherently broadcast in nature which makes them vulnerable to attacks. These attacks can disturb the operation of WSN and can even kill the purpose of their deployment. Wireless networks can be recognized of two sorts: infrastructure network and ad-hoc (infrastructure less) network. Infrastructure network is a sort of a network with fixed and wired gateways. A mobile host interacts with a bridge in the network within its communication radius. The mobile unit can mobile geographically while it is communicating. When it goes out of range of one base station, it connects with new base station and starts communicating through it. This phenomenon is termed as handoff. On the other hand, Mobile ad hoc network is an aggregation of wireless mobile nodes in which nodes team up by sending packets for each other to permit them to communicate outside range of direct wireless transmission. Ad hoc networks require no fixed network infrastructure such as base stations or access points, and could be rapidly and economically set up as required.