17981428
SECK: survivable and efficient clustered keying for wireless sensor networks
A wireless sensor network (WSN) typically consists of a large number of small sensor nodes and one or more high-end control and data aggregation nodes. Sensor nodes have limited computation and communication capabilities, and communicate via wireless links. Consequently, WSNs are highly vulnerable to attacks. This vulnerability is exacerbated when WSNs have to operate unattended in a hostile environment, such as battlefields. In this paper, we propose a novel self-organizing key management scheme for large-scale WSNs, called Sunivable and efficient clustered keying (SECK). Our scheme was designed specifically to address the key management issues within the low-tier of a hierarchical network architecture. Previous approaches for WSN key management adequately addressed operational issues, but to a large extent, ignored robustness and recoverability issues. Using simulation and analysis, we show that SECK is highly robust against key and node captures, and has noteworthy advantages over other key management schemes.
8823546
Performance and energy efficiency of block ciphers in personal digital assistants
Encryption algorithms can be used to help secure wireless communications, but securing data also consumes resources. The goal of this research is to provide users or system developers of personal digital assistants and applications with the associated time and energy costs of using specific encryption algorithms. Fouriblock ciphers (RC2, Blowfish, XTEA, and AES) were considered. The experiments included encryption and decryption tasks with different cipher and file size combinations. The resource impact of the block ciphers were evaluated using the latency, throughput, energy-latency product, and throughput/energy ratio metrics. We found that RC2 encrypts faster and uses less energyithan XTEA, followed by AES. The Blowfish cipher is a fast encryption algorithm, but the size of the plaintext affects its encryption speed and energy consumption. Faster algorithms seem to be more energy efficient because of differences in speed rather than differences in power consumption levels while encrypting.
10180647
Specularity elimination in range sensing for accurate 3D modeling of specular objects
We present a novel range sensing method that is capable of constructing accurate 3D models of specular objects. Our method utilizes a new range imaging concept called multipeak range imaging, which accounts for the effects of mutual reflections. False measurements generated by mutual reflections are then eliminated by applying a series of constraint tests based on local smoothness, global coordinate consistency and visibility consistency. We show the usefulness of our method by applying the method to three real objects with specular surfaces. The ground truth data for those three objects were also acquired in order to evaluate the elimination of false measurements and to justify the selection of the parameters in the constraint tests. Experimental results indicate that our method significantly improves upon the traditional methods for constructing reliable 3D models of specular objects with complex shapes.
42838112
Trusted Identity and Session Management Using Secure Cookies
The concept of federated identity management is increasingly coming to use in order to bring Service Providers closer to customers. Users are being provided an enriched experience while carrying out business on the Web at reduced overhead and improved customer service. The idea of maintaining a single profile and gaining access to multiple services has been accepted well by the customers. However, the benefits of breaking through just one set of credentials to gain access to multiple services has made the concept of Federated Identity Management of high interest to malicious users. In this paper, we analyze the structure of a generic Federated Identity Management System and explore the .NET Passport framework in depth. We explore the current security mechanisms adopted by the .NET Passport and identify potential security weaknesses. We then propose our new approaches to enhance the security services in .NET Passport by using Secure Cookies. Our approaches are transparent to and compatible with the current .NET Passport server. Finally, we prove the feasibility by implementing our ideas in a real system.
16813459
Scenario-based multitasking for real-time object-oriented models
Abstract Contemporary embedded systems quite often employ extremely complicated software consisting of a number of interrelated components, and this has made object-oriented design methodologies widely used in practice. To implement an object-oriented model in given target hardware, it is imperative to derive a set of tasks from the designed objects. This process of determining tasks and the events they handle greatly influences the real-time performance of the resultant system including response times and real-time guarantees. However, the innate discrepancies between objects and tasks make this exceedingly difficult, and many developers are forced to find their task sets through trial and error. In this paper, we propose Scenario-based Implementation Synthesis Architecture (SISA), an architecture consisting of a method for deriving a task set from a given object-oriented model and the development tools and run-time system architecture to support the method. A system developed with SISA guarantees the optimal response time for each event while deriving the smallest possible number of tasks. We have fully implemented SISA by extending the RoseRT development tool and applied it to an existing industrial PBX (private branch exchange) system. The experimental results show that SISA outperforms the best known conventional techniques by reducing maximum response times an average of 30.3%.
52850595
LOD Canny Edge Based Boundary Edge Selection for Human Body Tracking
We propose a simple method for tracking a nonparameterized subject contour in a single video stream with a moving camera and changing background. Our method is based on level-of-detail (LOD) Canny edge maps and graph-based routing operations on the LOD maps. LOD Canny edge maps are generated by changing scale parameters for a given image. Simple (strong) Canny edge map has the smallest number of edge pixels while the most detailed Canny edge map, Wcanny N , has the biggest number of edge pixels. We start our basic tracking using strong Canny edges generated from large image intensity gradients of an input image, called Scanny edges to reduce side-effects because of irrelevant edges. Starting from Scanny edges, we get more edge pixels ranging from simple Canny edge maps until the most detailed Canny edge maps. LOD Canny edge pixels become nodes in routing, and LOD values of adjacent edge pixels determine routing costs between the nodes. We find a best route to follow Canny edge pixels favoring stronger Canny edge pixels. Our accurate tracking is based on reducing effects from irrelevant edges by selecting the stronger edge pixels, thereby relying on the current frame edge pixel as much as possible contrary to other approaches of always combining the previous contour. Our experimental results show that this tracking approach is robust enough to handle a complex-textured scene.
9959276
Injecting RBAC to secure a Web-based workflow system
Web-based workflow systems have recently received much attention because they can support dynamic business processes over heterogeneous computing systems. Most existing web-based workflow systems, however, provide minimal security services such as authentication of users and network security. In this paper we describes an experiment in injecting role-based access control (RBAC) into an existing web-based workflow system. Specifically, we ensure that each task can only be executed by users belonging to a specific role. In order to achieve this, we define a simplified RBAC model to meet our needs and describe the security architecture to be applied to an existing web-based workflow system. We describe our implementation using commercial off-the-shelf (COTS) technology to demonstrate the feasibility of this approach. Our implementation uses X.509v3 certificates with role attribute, and employs a user-pull style where the client requests a client certificate from the role-server and presents it to the workflow system. A major goal of our implementation is to have minimal changes to the existing web server and no changes to the browser. We also discuss alternative architecture such as server-pull with LDAP (Lightweight Directory Access Protocol).