An RTP Extension for Reliable User-Data Transmission over VoIP Traffic
Covert channels are those breaking the restrictions of the legitimate channel and transmitting covert messages secretly. According to the modulation methods, the covert channels are separated into two types, which are the covert storage channel and the covert timing channel. Since the covert storage channel modulates a covert message into the shared storage space, both capacity and throughput exceed the covert timing channel, which guarantees the effectiveness of covert communication. In this paper, a covert storage channel over RTP is proposed and evaluated. Since mobile multimedia communication requires low transmission latency, the RTP based on UDP is widely utilized by VoIP applications. Through modifying the packet layout of RTP packets and embedding secret message sections into the target position, the covert message could be delivered to the receiver. However, since the RTP is not a reliable protocol, the transmission procedure could be infected by the network noise. To solve this, a transmission control mechanism with retransmission is designed for the scheme. Besides, the secret message is also encrypted with a secure encryption algorithm, which prevents message leakage. To evaluate the scheme, several experiments are deployed, and the scheme is proved to be reliable and secure.
KeywordsCovert storage channel RTP Reliable protocol VoIP
This work is supported by the National Key R&D Program of China (No. 2018YFB1004402), the Beijing Municipal Natural Science Foundation (No. 4172053).
- 2.Tuptuk, N., Hailes, S.: Covert channel attacks in pervasive computing. In: 2015 IEEE International Conference on Pervasive Computing and Communications (PerCom), pp. 236–242, St. Louis, MO, USA (2015). https://doi.org/10.1109/percom.2015.7146534
- 3.Rezaei, F., Hempel, M., Shrestha, P., Sharif, H.: Achieving robustness and capacity gains in covert timing channels. In: 2014 IEEE International Conference on Communications (ICC), pp. 969–974. IEEE, Sydney (2014). https://doi.org/10.1109/icc.2014.6-883445
- 4.Denney, K., Uluagac, A., Akkaya, K., Bhansali, S.: A novel storage covert channel on wearable devices using status bar notifications. In: 2016 13th IEEE Annual Consumer Communications & Networking Conference (CCNC). IEEE, Las Vegas (2016). https://doi.org/10.1109/ccnc.2016.7444898
- 5.Epishkina, A., Kogos, K.: Covert channels parameters evaluation using the information theory statements. In: 2015 5th International Conference on IT Convergence and Security (ICITCS). IEEE Press, Kuala Lumpur (2015). https://doi.org/10.1109/icitcs.2015.7-292966
- 6.Singh, A., Manchanda, K.: Establishment of bit selective mode storage covert channel in VA-NETS. In: 2015 IEEE International Conference on Computational Intelligence and Computing Research (ICCIC). IEEE Press, Madurai (2015). https://doi.org/10.1109/icc-ic.2015.7435732
- 9.Archibald, R., Ghosal, D.: A covert timing channel based on fountain codes. In: 2012 IEEE 11th International Conference on Trust, Security and Privacy in Computing and Communications. IEEE Press, Liverpool (2012). https://doi.org/10.1109/trustcom.2012.21
- 12.Archibald, R., Ghosal, D.: Design and analysis of a model-based Covert Timing Channel for Skype traffic. In: 2015 IEEE Conference on Communications and Network Security (CNS). IEEE Press, Florence (2015). https://doi.org/10.1109/cns.2015.7346833
- 13.Garcia, L., Senyondo, H., McLaughlin, S., Zonouz, S.: Covert channel communication through physical interdependencies in cyber-physical infrastructures. In: 2014 IEEE International Conference on Smart Grid Communications (SmartGridComm). IEEE Press, Venice (2014). https://doi.org/10.1109/smartgridcomm.2014.7007771
- 14.Elsadig, M., Fadlalla, Y.: A balanced approach to eliminate packet length-based covert channels. In: 2017 4th IEEE International Conference on Engineering Technologies and Applied Sciences (ICETAS). IEEE Press, Salmabad (2017). https://doi.org/10.1109/ice-tas.2017.8277839
- 17.Shrestha, P., Hempel, M., Sharif, H., Chen H.: An event-based unified system model to characterize and evaluate timing covert channels. IEEE Syst. J. 10(1) (2016). https://doi.org/10.1109/jsyst.2014.2328665
- 23.Tan, Y., Xu, X., Liang, C., Zhang, X., Zhang, Q., Li, Y.: An end-to-end covert channel via packet dropout for mobile networks. Int. J. Distrib. Sensor Netw. 14(5) (2018). https://doi.org/10.1177/155014771877956-8