Dynamic spectrum access (DSA) can effectively improve the spectrum efficiency and alleviate the spectrumscarcity, by allowing unlicensed secondary users (SUs) to access the licensed spectrumof primary users (PUs) opportunistically. Cooperative spectrum sharing is a new promising paradigm to provide necessary incentives for both PUs and SUs in dynamic spectrum access. The key idea is that […]
Optimal Sleep-Wake Scheduling for Energy Harvesting Smart Mobile Devices
In this paper, we develop optimal sleep/wake scheduling algorithms for smart mobile devices that are powered by batteries and are capable of harvesting energy from the environment. Using a novel combination of the two-timescale Lyapunov optimization approach and weight perturbation, we first design the Optimal Sleep/wake scheduling Algorithm (OSA), which does not require any knowledge […]
Near Optimal Data Gathering in Rechargeable Sensor Networks with a Mobile Sink
We study data gathering problem in Rechargeable Sensor Networks (RSNs) with a mobile sink, where rechargeable sensors are deployed into a region of interest to monitor the environment and a mobile sink travels along a pre-defined path to collect data from sensors periodically. In such RSNs, the optimal data gathering is challenging because the required […]
Cost-Effective Mapping between Wireless Body Area Networks and Cloud Service Providers Based on Multi-Stage Bargaining
This paper presents a bargaining-based resource allocation and price agreement in an environment of cloud-assisted Wireless Body Area Networks (WBANs). The challenge is to finalize a price agreement between the Cloud Service Providers (CSPs) and the WBANs, followed by a cost-effective mapping among them. Existing solutions primarily focus on profits of the CSPs, while guaranteeing […]
Design and Analysis of an Efficient Friend-to-Friend Content Dissemination System
Opportunistic communication, off-loading, and decentrlaized distribution have been proposed as a means of cost efficient disseminating content when users are geographically clustered into communities. Despite its promise, none of the proposed systems have not been widely adopted due to unbounded high content delivery latency, security, and privacy concerns. This paper, presents a novel hybrid content […]
Virtual Multipath Attack and Defense for Location Distinction in Wireless Networks
In wireless networks, location distinction aims to detect location changes or facilitate authentication of wireless users. To achieve location distinction, recent research has focused on investigating the spatial uncorrelation property of wireless channels. Specifically, differences in wireless channel characteristics are used to distinguish locations or identify location changes. However, we discover a new attack against […]
Using Virtual Machine Allocation Policies to Defend against Co-Resident Attacks in Cloud Computing
Cloud computing enables users to consume various IT resources in an on-demand manner, and with low management overhead. However, customers can face new security risks when they use cloud computing platforms. In this paper, we focus on one such threat—the co-resident attack, where malicious users build side channels and extract private information from virtual machines […]
Secure and Private Data Aggregation for Energy Consumption Scheduling in Smart Grids
The recent proposed solutions for demand side energy management leverage the two-way communication infrastructure provided by modern smart-meters and sharing the usage information with the other users. In this paper, we first highlight the privacy and security issues involved in the distributed demand management protocols. We propose a novel protocol to share required information among […]
My Privacy My Decision: Control of Photo Sharing on Online Social Networks
Photo sharing is an attractive feature which popularizes online social networks (OSNs). Unfortunately, it may leak users’ privacy if they are allowed to post, comment, and tag a photo freely. In this paper, we attempt to address this issue and study the scenario when a user shares a photo containing individuals other than himself/herself (termed […]
Efficient and Privacy-Preserving Min and kth Min Computations in Mobile Sensing Systems
Protecting the privacy of mobile phone user participants is extremely important for mobile phone sensing applications. In this paper, we study how an aggregator can expeditiously compute the minimum value or the kth minimum value of all users’ data without knowing them.We construct two secure protocols using probabilistic coding schemes and a cipher system that […]