16068554
The SIMBA user alert service architecture for dependable alert delivery
Alerts refer to the delivery of user-subscribed information to the user. As the number of alert services and the types of information delivery devices increase, a new model that allows users to manage alert delivery and avoid alert overflow is needed. The unique dependability challenge in the management of alerts is in the proper use of redundancy to achieve timeliness and reliability without being unduly intrusive or cumbersome. We describe the design, implementation, and user experience of an alert service architecture, called SIMBA. SIMBA utilizes Instant Messaging with acknowledgements as the universal, reliable alert delivery channel, with emails being the fallback channel. All alerts that a user subscribes to are first directed to the user's MyAlertBuddy, which allows centralized delivery preference customization and acts as a personal alert router to protect the privacy of user addresses. Delivery modes, each of which involves multiple user addresses to accommodate communication failures, are supported as an abstraction for specifying personalized dependability levels. A working implementation of the SIMBA system, which integrates five different types of alert services, is described. Challenges and techniques in maintaining a highly available MyAlertBuddy to avoid single-point of failure are discussed. The concept of exception handling automation is introduced for enhancing the robustness of applications that drive third-party communication client software through automation interfaces.
15335137
Automated Web Patrol with Strider HoneyMonkeys: Finding Web Sites That Exploit Browser Vulnerabilities
Internet attacks that use malicious web sites to install malware programs by exploiting browser vulnerabilities are a serious emerging threat. In response, we have developed an automated web patrol system to automatically identify and monitor these malicious sites. We describe the design and implementation of the Strider HoneyMonkey Exploit Detection System, which consists of a pipeline of “monkey programs” running possibly vulnerable browsers on virtual machines with different patch levels and patrolling the Web to seek out and classify web sites that exploit browser vulnerabilities. Within the first month of utilizing this system, we identified 752 unique URLs hosted on 288 web sites that could successfully exploit unpatched Windows XP machines. The system automatically constructed topology graphs based on traffic redirection to capture the relationship between the exploit sites. This allowed us to identify several major players who are responsible for a large number of exploit pages. By monitoring these 752 exploit-URLs on a daily basis, we discovered a malicious web site that was performing zero-day exploits of the unpatched javaprxy.dll vulnerability and was operating behind 25 exploit-URLs. It was confirmed as the first “inthe-wild”, zero-day exploit of this vulnerability that was reported to the Microsoft Security Response Center. Additionally, by scanning the most popular one million URLs as classified by a search engine, we found over seven hundred exploit-URLs, many of which serve popular content related to celebrities, song lyrics, wallpapers, video game cheats, and wrestling.
9300546
Detecting stealth software with Strider GhostBuster
Stealth malware programs that silently infect enterprise and consumer machines are becoming a major threat to the future of the Internet. Resource hiding is a powerful stealth technique commonly used by malware to evade detection by computer users and anti-malware scanners. In this paper, we focus on a subclass of malware, termed "ghostware", which hide files, configuration settings, processes, and loaded modules from the operating system's query and enumeration application programming interfaces (APIs). Instead of targeting individual stealth implementations, we describe a systematic framework for detecting multiple types of hidden resources by leveraging the hiding behavior as a detection mechanism. Specifically, we adopt a cross-view diff-based approach to ghostware detection by comparing a high-level infected scan with a low-level clean scan and alternatively comparing an inside-the-box infected scan with an outside-the-box clean scan. We describe the design and implementation of the Strider GhostBuster tool and demonstrate its efficiency and effectiveness in detecting resources hidden by real-world malware such as rootkits, Trojans, and key-loggers.
16817937
COMERA: COM Extensible Remoting Architecture
In a distributed object system, remoting architecture refers to the infrastructure that allows client programs to invoke methods on remote server objects in a transparent way. In this paper, we study the strength and limitations of current remoting architecture of COM (Component Object Model), and propose a new architecture called COMERA (COM Extensible Remoting Architecture) to enhance the extensibility and flexibility. We describe several application scenarios and implementations to demonstrate the power of such a componentized remoting architecture.
9543372
A cone-based distributed topology-control algorithm for wireless multi-hop networks
The topology of a wireless multi-hop network can be controlled by varying the transmission power at each node. In this paper, we give a detailed analysis of a cone-based distributed topology-control (CBTC) algorithm. This algorithm does not assume that nodes have GPS information available; rather it depends only on directional information. Roughly speaking, the basic idea of the algorithm is that a node u transmits with the minimum power p/sub u,/spl alpha// required to ensure that in every cone of degree /spl alpha/ around u, there is some node that u can reach with power p/sub u,/spl alpha//. We show that taking /spl alpha/=5/spl pi//6 is a necessary and sufficient condition to guarantee that network connectivity is preserved. More precisely, if there is a path from s to t when every node communicates at maximum power then, if /spl alpha//spl les/5/spl pi//6, there is still a path in the smallest symmetric graph G/sub /spl alpha// containing all edges (u,v) such that u can communicate with v using power p/sub u,/spl alpha//. On the other hand, if /spl alpha/>5/spl pi//6, connectivity is not necessarily preserved. We also propose a set of optimizations that further reduce power consumption and prove that they retain network connectivity. Dynamic reconfiguration in the presence of failures and mobility is also discussed. Simulation results are presented to demonstrate the effectiveness of the algorithm and the optimizations.
1564877
Analysis of a cone-based distributed topology control algorithm for wireless multi-hop networks
The topology of a wireless multi-hop network can be controlled by varying the transmission power at each node. In this paper, we give a detailed analysis of a cone-based distributed topology control algorithm. This algorithm, introduced in [16], does not assume that nodes have GPS information available; rather it depends only on directional information. Roughly speaking, the basic idea of the algorithm is that a node <i>u</i> transmits with the minimum power <i>p<subscrpt>u, α</subscrpt></i> required to ensure that in every cone of degree α around <i>u</i>, there is some node that <i>u</i> can reach with power <i>p<subscrpt>u, α</subscrpt></i>. We show that taking α = 5π/6 is a necessary and sufficient condition to guarantee that network connectivity is preserved. More precisely, if there is a path from <i>s</i> to <i>t</i> when every node communicates at maximum power then, if α ⪇ 5π/6, there is still a path in the smallest symmetric graph <i>G</i><subscrpt>α</subscrpt> containing all edges (<i>u, v</i>) such that <i>u</i> can communicate with <i>v</i> using power <i>p<subscrpt>u, α</subscrpt></i>. On the other hand, if α > 5π/6, connectivity is not necessarily preserved. We also propose a set of optimizations that further reduce power consumption and prove that they retain network connectivity. Dynamic reconfiguration in the presence of failures and mobility is also discussed. Simulation results are presented to demonstrate the effectiveness of the algorithm and the optimizations.
1917143
Wireless Sensing, Actuation and Control - With Applications to Civil Structures
Structural monitoring and control have been subjects of interests in structural engineering for quite some time. Structural sensing and control technologies can benefit in terms of installation cost and time from wireless communication and embedded computing. The hardware and software requirements pose an interesting, interdisciplinary research challenge. This paper describes a low-cost wireless sensing system that is judiciously designed for large-scale applications in civil structures. Laboratory and field tests have been conducted to validate the performance of the prototype system for measuring vibration responses. By incorporating an actuation signal generation interface, the wireless sensing system has the capabilities to perform structural actuation and support structural control applications. Structural control tests have been performed to validate the wireless sensing and actuation system.
16315333
Computing feedback laws for linear systems with a parallel pieri homotopy
Homotopy methods to solve polynomial systems are well suited for parallel computing because the solution paths defined by the homotopy can be tracked independently. Both the static and dynamic load balancing models are implemented in C with MPI, adapting PHCpack written in Ada using gcc, and tested on academic benchmarks and mechanical applications. We studied the parallelization of Pieri homotopies to compute all feedback laws to control linear systems. To distribute the workload, we mapped the poset onto a tree. As the dimensions of the Pieri homotopies grow incrementally from the root to the leaves in the tree, we found the Pieri homotopies well suited for parallel computing.
1622745
Replication-based efficient data delivery scheme (red) for delay/fault-tolerant mobile sensor network (DFT-MSN)
The delay/fault-tolerant mobile sensor network (DFT-MSN) has been proposed recently for pervasive information gathering. DFT-MSN distinguishes itself from conventional sensor networks by several unique characteristics such as sensor mobility, loose connectivity, and delay/fault tolerability. The mainstream approaches for sensor networking/communication cannot be applied in DFT-MSN directly. In this paper we propose a replication-based efficient data delivery (RED) scheme based on erasure coding technology tailored for DFT-MSN. RED consists of two key components for data transmission and message management, respectively. The former makes decision on when and where to transmit data messages according to the delivery probability. The latter decides the optimal erasure coding parameters (including the number of data blocks and the needed redundancy) based on its current delivery probability, in order to achieve the desired data delivery ratio while minimizing overhead at the same time. Extensive simulation has been carried out for performance evaluation. Compared with other approaches, the proposed RED data delivery scheme achieves high message delivery ratio with low transmission overhead and data management complexity
1683130
PLA-based runtime dynamism in support of privacy-enhanced Web personalization
Software product line architectures (PLAs) have been widely recognized as a successful approach in industrial software development for improving productivity, software quality and time-to-market. In this paper, we focus on the usage of a PLA for a quite different purpose, namely, handling privacy constraints in Web personalization. To provide personalized services such as customized recommendations, a personalized Website collects users' personal data, which raises various privacy concerns. We aim at reconciling the benefits of web personalization with privacy constraints that come from users themselves as well as from privacy legislations and regulations that apply to a given user. We propose a dynamic, privacy-enabling personalization infrastructure and conceive it as a PLA. This infrastructure allows for dynamically selecting and instantiating personalization architectures that provide personalized services to each individual user and comply with the prevailing privacy constraints
10803461
Iterative normalization of cDNA microarray data
Describes an approach to normalizing microarray expression data. The novel feature is to unify the tasks of estimating normalization coefficients and identifying the control gene set. Unification is realized by constructing a window function over the scatter plot defining the subset of constantly expressed genes and by affecting optimization using an iterative procedure. The structure of window function gates contributions to the control gene set used to estimate normalization coefficients. This window measures the consistency of the matched neighborhoods in the scatter plot and provides a means of rejecting control gene outliers. The recovery of normalizational regression and control gene selection are interleaved and are realized by applying coupled operations to the mean square error function. In this way, the two processes bootstrap one another. We evaluate the technique on real microarray data from breast cancer cell lines and complement the experiment with a data cluster visualization study.