Ali Chehab

Privacy as a Service: Privacy-Aware Data Storage and Processing in Cloud Computing Architectures

In this paper we present PasS (Privacy as a Service); a set of security protocols for ensuring the privacy and legal compliance of customer data in cloud computing architectures. PasS allows for the secure storage and processing of users’ confidential data by leveraging the tamper-proof capabilities of cryptographic coprocessors. Using tamper-proof facilities provides a secure execution domain in the computing cloud that is physically and logically protected from unauthorized access. PasS central design goal is to maximize users’ control in managing the various aspects related to the privacy of sensitive data. This is achieved by implementing user-configurable software protection and data privacy mechanisms. Moreover, PasS provides a privacy feedback process which informs users of the different privacy operations applied on their data and makes them aware of any potential risks that may jeopardize the confidentiality of their sensitive information. To the best of our knowledge, PasS is the first practical cloud computing privacy solution that utilizes previous research on cryptographic coprocessors to solve the problem of securely processing sensitive data in cloud computing infrastructures.

Energy-efficient incremental integrity for securing storage in mobile cloud computing

We present an energy-efficient protocol for ensuring the integrity of storage services in mobile cloud computing. The proposed protocol applies the concepts of incremental cryptography and trusted computing to design secure integrity data structures that protect the customer data while highly reducing the mobile client energy consumption and efficiently supporting dynamic data operations. The system design is analytically analyzed and experimentally implemented to demonstrate the energy savings it provides on mobile clients.

TRUMMAR - a trust model for mobile agent systems based on reputation

In this paper we present TRUMMAR, a reputation-based trust model that mobile agent systems can use to protect agents from malicious hosts. TRUMMAR is unique in being a truly comprehensive model since it accounts, in a unified framework, for a multitude of concepts such as prior-derived reputation, first impression, loss of reputation information with time, hierarchy of host systems (neighbors, friends, and strangers), and the inclusion of interaction results in reputation calculation. TRUMMAR is also general enough to be applied to any distributed system. We show simulation results that verify the correctness of this model and the effects of its various parameters.

Original research paper: Fuzzy reputation-based trust model

We present PATROL-F (comPrehensive reputAtion-based TRust mOdeL with Fuzzy subsystems) as a comprehensive model for reputation-based trust incorporating fuzzy subsystems to protect interacting hosts in distributed systems. PATROL-F is the fuzzy version of our previous model PATROL, and aims at achieving a truly unique model incorporating various concepts that are important for the calculation of reputation values and the corresponding decisions of whether or not to trust. Among the incorporated concepts are direct experiences and reputation values, the credibility of a host to give recommendations, the decay of information with time based on a dynamic decay factor, first impressions, and a hierarchy of host systems. The model also implements the concepts of similarity, popularity, activity, and cooperation among hosts. In addition, PATROL-Fs fuzzy subsystems account for humanistic and subjective concepts such as the importance of a transaction, the decision in the uncertainty region, and setting the result of interaction. We present simulations of PATROL-F and show its correctness and reliability.

A Privacy-Preserving Trust Model for VANETs

Vehicular ad hoc network (VANET) is a promising technology for providing safer roads and a more efficient driving experience. However, the deployment of VANETs is dependent on several issues in security and privacy. In this paper, a trust-based privacy-preserving model for VANETs is presented. The model is unique in its ability to protect privacy while maintaining accurate reputation-based trust. We use the notion of groups in order to make the VANET users anonymous within their groups and yet identifiable and accountable to their group managers. The use of groups simplifies the task of building reputation and calculating trust in the received messages in order to provide better and more confident decisions. We present simulations of the proposed model that verify its correctness and reliability.

Wireless Sensor for Continuous Real-Time Oil Spill Thickness and Location Measurement

Marine pollution by oil spills is a devastating environmental hazard, requiring a low-cost efficient system for continuous and real-time thickness measurement and localization of oil. Knowing that none of the previous detection methods has managed to fully meet these requirements, it is necessary to devise a new technique for guiding and speeding up the clean-up process of oil spills. This paper presents a sensor device that is capable of sensing, processing, and transmitting information about an oil spill (location and thickness). This paper discusses two new methodologies of detection based on the difference in the absorbance spectral signatures and electric conductivity properties of oil and water. This paper also discusses the mechanical design of the device, the hardware implementation of its components, and the integration and evaluation of the whole system. The experimental results confirm the effectiveness of the proposed method under different lighting, salinity, temperature, and sea conditions.

PATROL-F – a comprehensive reputation-based trust model with fuzzy subsystems

In this paper, we present PATROL-F, a comprehensive model for reputation-based trust incorporating fuzzy subsystems to protect interacting hosts in distributed systems. PATROL-F is the fuzzy version of our previous model PATROL, and aims at achieving a truly unique model incorporating various concepts that are important for the calculation of reputation values and the corresponding trust decisions. Among the incorporated concepts are direct experiences and reputation values, the credibility of a host to give recommend-dations, the decay of information with time based on a dynamic decay factor, first impressions, and a hierarchy of host systems. The model also implements the concepts of similarity, popularity, activity, and cooperation among hosts. In addition, PATROL-F includes fuzzy subsystems to account for humanistic and subjective concepts such as the importance of a transaction, the decision in the uncertainty region, and setting the value of result of interaction. We present simulations of PATROL-F and show its correctness and reliability.

PATROL: a comprehensive reputation-based trust model

In this paper, we present PATROL, a general and comprehensive reputation-based trust model for distributed computing. The proposed model is an enhancement over our previous model, TRUMMAR, and aims at achieving a truly unique model that incorporates most concepts that are essential to determining trust-based decisions. Among the concepts upon which the trust model is based are reputation values, direct experiences, trust in the credibility of a host to give recommendations, decay of information with time based on a dynamic decay factor, first impressions, similarity, popularity, activity, cooperation between hosts, in addition to a hierarchy of host systems. The simulations performed on this model confirm its correctness and its adaptability to different environments and situations.

A comprehensive reputation-based trust model for distributed systems

In this paper, we present a general and comprehensive reputation-based trust model for distributed computing. The proposed model is an enhancement over our previous model, TRUMMAR, and aims at achieving a truly unique model that incorporates most concepts that are essential to determining trust-based decisions. Among the concepts upon which the trust model is based are reputation values, direct experiences, trust in the credibility of a host to give recommendations, decay of information with time based on a dynamic decay factor, first impressions, similarity, popularity, activity, cooperation between hosts, in addition to a hierarchy of host systems. The simulations performed on this model confirm its correctness and its adaptability to different environments and situations.

i/sub DDT/ test methodologies for very deep sub-micron CMOS circuits

In this paper, we investigate three i/sub DDT/-based test methodologies, Double Threshold i/sub DDT/, Delta i/sub DDT/, and Delayed i/sub DDT/, and we compare their effectiveness in the detection of defects in very deep sub-micron random logic circuits. The target defects are resistive opens and resistive bridges. We present preliminary simulation results of 49 defects to study the defect sensitivity of each of the three test methods. This paper reports our preliminary results on these three test methods using a relatively small transistor-level sample circuit, and is not intended to imply any feasibility in a production environment. The test methods presented herein are the subject of a current invention disclosure.