Mobile VoIP Security System Research And Implementation

With the rapid development of mobile communication, as well as the emergence of new technologies and products, mobile terminals have extended their capability from only supporting the mobile network to supporting both the mobile and the wireless networks like Wi-Fi and Bluetooth and laid the foundations necessary for the development of mobile VoIP. VoIP, on its unique features of flexibility and efficiency, is receiving the attention from more and more families and enterprise customers. Although currently mobile VoIP has made certain development, it still faces many challenges in its commercialization process, including the quality of service and the mobile communication security.This paper focuses on SIP-based VoIP system is the main research object and the main work of this paper could be represented in two aspects. The first one is the study on threats in SIP-based VoIP system and its existing security mechanisms, while the second is the presentation of the corresponding solution and the implementation of a secure mobile VoIP system which takes challenges from aspects like authentication, key management and end-to-end encryption into consideration.The main contributions of this paper are:1. Study of VoIP architecture and security mechanisms, including related protocols, system components, message flow, security threats and requirements.2. A new VoIP authentication protocol presented for mobile communication, which could strengthen the current VoIP authentication. 3. A key management scheme based on symmetric encryption is provided which is used to distribute the shared key for mobile terminals lacking of computing power.4. In order to reduce the error rate of voice decryption due to voice packet loss and out of order in UDP transmission, a synchronous frame is designed in this paper to help the system make key stream synchronization and properly restore the voice.5. Design and implementation of a SIP-based secure mobile VoIP system; including authentication, key management and end-to-end voice encryption, as well as the test and evaluation of its functionality, real-time performance and security.