Steganography in VoIP networks

Abstract

The primary aim of this bachelor thesis is to evaluate Steganography techniques in VoIP networks. IP telephony is nowadays a very popular IP network service and its popularity is still rapidly rising. A high traffic volume of data that VoIP generates offers a well hidden-communication possibility. Steganography is an ancient art that encompasses many data hiding techniques that the main purpose is hiding the very existence of the communication. Due to VoIP well hidden-communication possibilities, a Steganography in VoIP is feasible and became a very interesting area for further exploration. Steganography method LACK is presented in the thesis. LACK utilizes an excessively delayed RTP packets for steganography purposes. For the purpose of call analysis, R-factor and MOS are calculated. The results of LACK impact on calls quality are presented, and achievable steganographic bandwidth is calculated. The efficiency of hiding data in RTCP packets is summarized. A possibility of hiding data in SRTP is also presented. At the end of the thesis, the effectiveness of Steganography techniques in VoIP networks is evaluated.