Bluetooth is the widely used technology for the short range communication. Security has become a major concern in the usage of Bluetooth. In this paper, an enhanced security framework is developed for Bluetooth based networks. A Security controller is proposed on top of the Link Layer of the Bluetooth Stack for message authentication and integrity in the scatternet scenario. As NS2 has no provision for security protocols, a newalgorithm is written especially for the security purpose and added to the NS2 package. The Security algorithm used is Modified RSA (Rivest-Shamir-Adleman) for providing digital signature, encryption and decryption. The simulation shows how the data transfer takes place between the nodes in the Bluetooth network scenario with the implementation of the added security protocol. © 2014 IEEE.