On the role of the degrees of freedom of the electromagnetic field in unconditional secure wireless communication

Hong Wen

Yahui Ji, Jiguo Yu, Yan Yao +3 more

Marco Donald Migliore, Daniele Pinchera, Mario Lucido +2 more

Recently there has been an increasing interest toward unconditionally secure communication systems in which the mechanism assuring the secrecy of the message is physical and not computational. An interesting approach proposed in the information theory literature for unconditionally secure communication is based on the use of artificial noise at a rate related to the difference between the mutual information in perfect secrecy. Since the mechanism assuring the secrecy of the message is physical and not computational, the unauthorized receiver cannot obtain information from the received signal, regardless of how much computational power is available. For this reason, such a cryptographic system is called unconditionally secure. The aim of this paper is to investigate an electromagnetic approach to the noise-based wireless communication systems stressing the important role of the electromagnetic propagation and antenna design. In particular, the concept of the number of degrees of freedom of the field is used to clarify the physical mechanism that allows for a decrease in the mutual information of the unauthorized channel compared to the eavesdropper channel. Numerical examples regarding both free-space propagation and rich scattering environments are shown, confirming the importance of the role of the electromagnetic propagation and antenna design.

Şennur Ulukuş, Ersen Ekrem

Marco Donald Migliore, C. D'Elia, Daniele Pinchera

The fast growing of personal wireless communications, and the spreading of new services like Internet banking on mobile phones, has made the preventing unauthorized extraction of information a key problem for wireless systems. However, all the ciphering algorithms developed since now can be broken under an attack with unlimited computational resource. Consequently, the final goal of the cryptography is the developing of an unconditionally secure cryptographic system able to resist to any cryptanalytic attack, no matter how much computation power is available.

Y.-W. Peter Hong, Pang-Chang Lan, C.‐C. Jay Kuo