Nowadays wireless sensor networks are mostly used for environmental control, surveillance tasks, monitoring, tracking and controlling etc. For this, the wireless sensor network has to be safe and efficient. Clustering is one of the most successful techniques to improve system performance in Wireless Sensor Network(WSN). Security is based on Digital Signature and which is using two protocols, Secure and Efficient data Transmission by Identity Based digital Signature (SET IBS) and Secure and Efficient data Transmission by Identity Based Online/Offline digital Signature (SET IBOOS). Most probably, the Elliptical Curve Cryptography (ECC) algorithm is used for data transmission. By using these protocols, the attacker can be recognized easily and energy burning is also reduced. In this paper, we maximize the time of first node dies (FND) in a WSN to extend the network lifetime.