Journal Homepage: www.ijcst.org

Abstract — Lawful Interception is a very basic method used by the law enforcement agency (LEA) all over the world for identifying criminal act and actors by monitoring telecommunication network. It plays an important role for the homeland security. As soon as the VoIP is introduced, people switches from traditional telephone system to VoIP due to higher speeds, low cost, support for mobility, and easy nature for encryption. But there are some issues such as misuse of intercepted data by the members of LEA, privacy concern of the individuals, cost, legal liabilities, etc. On the other hand, VoIP has become a popular means of communication tool for the criminals and terrorists – as VoIP provides secure conversation by encrypting the messages transferred between two communication parties. Besides other difficulties for interception cause due to the architecture of the VoIP and use of smart devices – thus it is hard to intercept both the signaling and call contents [1]. This paper presents a Trusted Third Party (TTP) or Key Escrow Agent based Lawful Interception (LI) model that would provide lawful interception over VoIP while ensuring the individual privacy