Ad hoc networks are highly dynamic routing networks cooperated by a collection of wireless mobile hosts without any assistance of centralized access point. Secure Efficient Ad hoc Distance Vector (SEAD) is a proactive routing protocol, based on the design of Destination Sequenced Distance Vector routing protocol (DSDV). SEAD provides a robust protocol against attackers trying to create incorrect routing state in other node. However, it does not provide a way to prevent an attacker from tampering the next hop or the destination field in route update. In this paper, we proposed an I-SEAD protocol to solve the problem. A series of simulation experiments are conducted to evaluate the performance.