Artificial-Noise Alignment for Secure Multicast using Multiple Antennas

Abstract

We propose an artificial-noise alignment scheme for multicasting a common-confidential message to a group of legitimate receivers. Our scheme transmits a superposition of information and noise symbols. At each legitimate receiver, the noise symbols are aligned in such a way that the information symbols can be decoded with high probability. In contrast, the noise symbols completely mask the information symbols at the eavesdroppers. Our proposed scheme does not use the knowledge of the eavesdropper's channel gains at the transmitter for alignment, yet it achieves the best-known lower bound on the secure degrees of freedom. The knowledge of the eavesdropper's channel gains is still necessary when selecting the rate of the wiretap code. Our scheme is also a natural generalization of the approach of transmitting artificial noise in the null-space of the legitimate receiver's channel, previously proposed in the literature.Index Terms-Artificial-noise alignment, secure multicast, multiple antennas.

Physical-Layer Security against Non-Degraded Eavesdroppers

“…Another dimension to explore against non-degraded eavesdroppers is that of a jamming receiver. While interference alignment is a promising approach [3] for effective jamming of eavesdroppers with reduced impact on legitimate receivers, current designs suffer from several shortcomings and limiting assumptions. For example, most works are of theoretical nature and their applicability in practical scenarios with several decentralized interferers depends on strict synchronization among devices.…”

“…These works typically assume that an eavesdropper adversary is, at least in some periods of time, in a degraded situation. This can be enabled, for instance, by (a) having the eavesdropper on a disadvantaged position/location with respect to the legitimate receiver, (b) the eavesdropper suffering interference [2] that can possibly be removed at the legitimate receiver [3], or (c) using relays to improve the quality of information available at the receiver [4]. This is legitimate if, for example, there is a protected area such as a warehouse of RFID devices where eavesdroppers are not able to enter [5], or cooperative devices are able to strictly synchronize with legitimate devices.…”

A Location Prediction-Based Helper Selection Scheme for Suspicious Eavesdroppers

“…The general solution is to guarantee the robust secrecy performance in the worst case and to design a suboptimal algorithm. Also, there exist other tactical methods, such as the artificial noise alignment schemes [16] that do not use the knowledge of the eavesdroppers channel gains. Among these schemes, few of them consider a network model with a mobile eavesdropper, whose CSI is unknown to legitimate users because of the unexpected movement.…”

Secure degrees of freedom of the Gaussian wiretap channel with helpers and no eavesdropper CSI: Blind cooperative jamming

“…In this case, the message signals and the cooperative jamming signals are sent in such a way that: 1) all M + 1 cooperative jamming signals are aligned at the legitimate receiver in the same irrational dimension, and 2) all cooperative jamming signals span the entire space at the eavesdropper to limit the information leakage to the eavesdropper. We use insights from [3], which developed a new achievable scheme that achieved the same secure d.o.f. as in [26] without eavesdropper CSI, to show that the information leakage to the eavesdropper is upper bounded by a function, which can be made arbitrarily small.…”