Effective Model for Real Time End to End Secure Communication Over GSM Voice Channel

Due to the availability, robustness and reliability; Global System for Mobile Communications (GSM) plays a vital role in our daily life. GSM security is not so strong and is susceptible to attacks. One of the most important issues is insecurity in voice communicated over the GSM. While the system provides limited voice security over air links through encryption; yet, availability of a solution, that provides end-to-end secure voice assurance, is considered important to meet user security requirements. To make the communication secure (end-to-end) one option is to encrypt the speech and then transmit it over GSM channel. In this paper, a novel approach is proposed for secure end-to-end voice communication over GSM. The biggest challenge is that the GSM channel only transmits speech like a symbol; therefore, a modulation technique is required which can effectively generate modulation signal similar to the human voice. Next problem in this regard is the requirement of associated encryption and speech compression technique. The proposed methodology uses codec2 700 bits/s as an encoder and decoder, with coherent PSK as a modulation and demodulation technique. In addition to this KASUMI based encryption algorithm is adopted which best fits in our proposed flow. The quality assessment of the speech after its reconstruction on the receiver side has shown good results. The proposed methodology has shown viable results on the computer-based system as well as an embedded system.