Physical Layer Secrecy

The two fundamental characteristics of the wireless medium, namely broadcast and superposition, present different challenges in ensuring reliable and secure communication in the presence of adversarial users. In recent years, physical layer secrecy has gained significant interest as an alternative to traditional key-based enciphering for the wireless networks. The philosophy behind physical layer secrecy is to exploit the inherent randomness present in noise and communication channel (such as fading) to keep the message confidential from the eavesdropper.

The primary objective of research in this direction is to obtain fundamental limits of secure communication over noisy/interference limited scenarios. Such results help to determine the effect of noise or interference on the performance of the system. For each communication model, there exists a maximum rate, above which secure communication is impossible (secrecy capacity). Hence, it is very important to characterize the secrecy capacity or to obtain approximate characterization of capacity (secure degrees of freedom, generalized degress of freedom) of communication systems.

Topics of current interest

  • Cooperative communication for secrecy

  • Integration of physical layer secrecy into wireless systems

  • Security for Internet of Things (IoT)

Our contributions

  1. P. Mohapatra, C. R. Murthy and J. Lee, On the Secrecy Capacity Region of the 2-user Symmetric Z Interference Channel with Unidirectional Transmitter Cooperation, submitted to IEEE Trans. on Information Forensics and Security, April 2016.

  2. P. Mohapatra and C. R. Murthy, On the Capacity of the 2-User Interference Channel with Transmitter Cooperation and Secrecy Constraints, Accepted, IEEE Transactions on Information Theory, May 2016.

    1. P. Mohapatra and C. R. Murthy, Outer Bounds on the Secrecy Rate of the 2-User Symmetric Deterministic Interference Channel with Transmitter Cooperation, Proc. National Conference on Communications (NCC), IIT Kanpur, India, Feb. 2014.

    2. P. Mohapatra and C. R. Murthy, Secrecy in the 2-User Symmetric Deterministic Interference Channel with Transmitter Cooperation, Proc. IEEE 14th Workshop on Signal Processing Advances in Wireless Communications (SPAWC), Darmstadt, Germany, Jun. 2013. (Also accepted for Poster Presentation at the Comm. Theory Workshop, Phuket, Thailand, Jun. 2013.)

    1. P. Mohapatra and C. R. Murthy, Capacity of the Deterministic Z-Interference Channel with Unidirectional Transmitter Cooperation and Secrecy Constraints, ISIT, Hong Kong, June 2015.