Security is the major area of concern in communication channel. Security is very crucial in wireless sensor networks which are deployed in remote environments. Adversary can disrupt the communication within multi hop sensor networks by launching the attack. The common attacks which disrupt the communication of nodes are packet dropping, packet modification, packet fake routing, badmouthing attack and Sybil attack. In this paper we considered these attacks and presented a solution to identify the attacks. Many approaches have been proposed to diminish these attacks, but very few methods can detect these attacks effectively. In this simple scheme, every node selects a parent node to forward the packet towards base station or sink. Each node append its unique identity and trust to the parent as a path marker. It encrypts the bytes using a secret key generated and shared among the sink. The encrypted packet is then forwarded to the parent node. Base station can identify the malicious nodes by using these unique identity and trust value. پرونده مقاله