Mustafa El-Halabi

Secrecy Capacity per Unit Cost

The concept of channel capacity per unit cost was introduced by Verdu in 1990 to study the limits of cost-efficient wide-band communication. It was shown that orthogonal signaling can achieve the channel capacity per unit cost of memoryless stationary channels with a zero-cost input letter. This paper introduces a concept of secrecy capacity per unit cost to study cost-efficient wide-band secrecy communication. For degraded memoryless stationary wiretap channels, it is shown that an orthogonal coding scheme with randomized pulse position and constant pulse shape achieves the secrecy capacity per unit cost with a zero-cost input letter. For general memoryless stationary wiretap channels, the performance of orthogonal codes is studied, and the benefit of further randomizing the pulse shape is demonstrated via a simple example.

Secret Writing on Dirty Paper: A Deterministic View

Recently, there has been a lot of success in using the deterministic approach to provide approximate characterization of Gaussian network capacity. In this paper, we take a deterministic view and revisit the problem of wiretap channel with side information. A precise characterization of the secrecy capacity is obtained for a linear deterministic model, which naturally suggests a coding scheme which we show to achieve the secrecy capacity of the degraded Gaussian model (dubbed as “secret writing on dirty paper”) to within half a bit.

Secret writing on dirty paper: A deterministic view

Recently, there has been a lot of success in using the deterministic approach to provide approximate characterization of Gaussian network capacity. In this paper, we take a deterministic view and revisit the problem of wiretap channel with side information. A precise characterization of the secrecy capacity is obtained for a linear deterministic model, which naturally suggests a coding scheme which we show to achieve the secrecy capacity of the degraded Gaussian model (dubbed as “secret writing on dirty paper”) to within half a bit.

A distortion-theoretic perspective for redundant metering security in a smart grid

In a smart grid environment some customers employ third-party meters and terminals for integrity verification of the smart meter power measurements reported by the electric utility company. We address the security issues that may arise under the presence of a third-party wireless terminal. In this paper we consider a rate-distortion perspective that contrasts the Slepian-Wolf distortionless coding approach recently presented by Varodayan and Gao [1] for integrity verification through redundant metering. We show that through the use of a limited secret key, we can impose a certain minimum distortion on the eavesdropper, while enabling the wireless terminal to retrieve the measurements losslessly with high probability. We highlight the advantages of our approach.

On secrecy capacity per unit cost

The concept of channel capacity per unit cost was introduced by Verdú in 1990 to study the limits of wideband communication. It was shown that an orthogonal coding scheme achieves the channel capacity per unit cost of memoryless stationary channels with a zero-cost input letter. This paper introduces the concept of secrecy capacity per unit cost to study wideband secrecy communications. For degraded memoryless stationary wiretap channels, it is shown that an orthogonal coding scheme achieves the secrecy capacity per unit cost with a zero-cost input letter. For general memoryless stationary wiretap channels, the performance of orthogonal codes is studied and lower and upper bounds on the secrecy capacity per unit cost are provided.

Eye-blinks communication vehicle: A prototype

Amyotrophic lateral sclerosis (ALS) is a paralytic disorder that affects muscles by weakening them, until reaching a certain stage of immobility, where the patient could only move his/her eyes. ALS-inflicted victims have been increasing over the past few years with no cure to be found. This has lead to a proliferation of special-aid gadgets, which are tailored to improve the life conditions of those patients. This paper proposes a cost-efficient prototype for an intelligent aid-vehicle that works by interpreting the blinking movements of the ALS patients eyes. The aid-vehicle is equipped with a pad that controls the motion of the motors, a virtual keyboard that can be used to type its users thoughts via eye movement and blinking, and several sensors that aid to stop the vehicle whenever an obstacle is detected. The aid-vehicle is designed to be used indoors and outdoors. It is user-friendly, easy to manipulate, and offers ALS patients a mean to be less dependent on others, and a way to communicate with the outside world at an affordable price, with the hope that it would contribute to the longevity of ALS patients.

Physical-layer security for multi-antenna wiretap channel in the wideband regime

Perfect security for the multi-antenna wiretap channel is considered, at the physical layer, under a limited-energy constraint. The problem was originally considered in [1] for point-to-point channels, where the fundamental limits of secure communication have been established in the wideband regime. In this paper, the more general multi-antenna scenario is addressed. The main result proves that the secrecy capacity per unit cost (energy), under the mild condition of zero-cost input letter, can be achieved using a structured orthogonal random binning coding scheme.

Secure communication with side information and constrained encoding

Two main ingredients that enable wiretap codes to achieve information-theoretic secrecy are their binning structure and the randomization among multiple codewords. The presence of an infinite amount of randomness is an oversimplifying assumption which act as a hurdle that prevents the development of practical codes for wiretap channels. In this paper, we investigate the trade-off between the achievable secrecy rate and the randomness rate for wiretap channels with side information, non-causally known to the transmitter. Using the linear deterministic approach, we present insights into finding near-optimal codes under limited randomness.