In this paper, we formulate an analytical model to characterize the spread of malware in decentralized, Gnutella type peer-to-peer (P2P) networks and study the dynamics associated with the spread of malware. Using a compartmental model, we derive the system parameters or network conditions under which the P2P network may reach a malware free equilibrium. The […]
Traceback of DDoS Attacks Using Entropy Variations
Distributed Denial-of-Service (DDoS) attacks are a critical threat to the Internet. However, the memoryless feature of the Internet routing mechanisms makes it extremely hard to trace back to the source of these attacks. As a result, there is no effective and efficient method to deal with this issue so far. In this paper, we propose […]
Comparative Evaluation of Spoofing Defenses
IP spoofing exacerbates many security threats, and reducing it would greatly enhance Internet security. Seven defenses that filter spoofed traffic have been proposed to date; three are designed for end-network deployment, while four assume some collaboration with core routers for packet marking or filtering. Because each defense has been evaluated in a unique setting, the […]
Providing e-Transaction Guarantees in Asynchronous Systems with No Assumptions on the Accuracy of Failure Detection
n this paper, we address reliability issues in three-tier systems with stateless application servers. For these systems, a framework called e-Transaction has been recently proposed, which specifies a set of desirable end-to-end reliability guarantees. In this article, we propose an innovative distributed protocol providing e-Transaction guarantees in the general case of multiple, autonomous back-end databases […]
An Obfuscation-Based Approach for Protecting Location Privacy
The pervasive diffusion of mobile communication devices and the technical improvements of location techniques are fostering the development of new applications that use the physical position of users to offer location-based services for business, social, or informational purposes. In such a context, privacy concerns are increasing and call for sophisticated solutions able to guarantee different […]
metadata distribution and consistency techniques for large scale cluster file systems
Most supercomputers nowadays are based on large clusters, which call for sophisticated, scalable, and decentralized metadata processing techniques. From the perspective of maximizing metadata throughput, an ideal metadata distribution policy should automatically balance the namespace locality and even distribution without manual intervention. None of existing metadata distribution schemes is designed to make such a balance. […]
A Privacy-Preserving Location Monitoring System for Wireless Sensor Networks
Monitoring personal locations with a potentially untrusted server poses privacy threats to the monitored individuals. To this end, we propose a privacy-preserving location monitoring system for wireless sensor networks. In our system, we design two in-network location anonymization algorithms, namely, resource and quality-aware algorithms, that aim to enable the system to provide high-quality location monitoring […]
Efficient Data Collection in Wireless Sensor Networks with Path-Constrained Mobile Sinks
Recent work shows that sink mobility along a constrained path can improve the energy efficiency in wireless sensor networks. However, due to the path constraint, a mobile sink with constant speed has limited communication time to collect data from the sensor nodes deployed randomly. This poses significant challenges in simultaneously improving the amount of data […]
On Reliable Broadcast in Low Duty-Cycle Wireless Sensor Networks
Broadcast is one of the most fundamental services in wireless sensor networks, where a distinct feature is that sensor nodes may alternate between active and dormant states, so as to conserve energy and extend the network lifetime. Unfortunately, the impact of such cycles has been largely ignored in existing broadcast implementations that adopt the common […]
Fast Data Collection in Tree-Based Wireless Sensor Networks
We investigate the following fundamental question – how fast can information be collected from a wireless sensor network organized as tree? To address this, we explore and evaluate a number of techniques using realistic simulation models under the many-to-one communication paradigm known as convergecast. We first consider time scheduling on a single frequency channel with […]