Abstract: Mobile Ad hoc NETwork (MANET) have been now seen as the advancement of network models. It involves mobility and hierarchy of network elements on it positive side. The two different parameters of prime importance in MANET are energy efficiency and security. This paper proposes the idea of combining these two factors. It involves a novel idea of dynamic re-clustering to address energy efficiency. Security have been incorporated in data transmission stage by a secure intrusion detection algorithm. Compared to conventional approaches the combination of these two ideas have improved the performance parameters without affecting network performance.