This paper presents ESCAPE, an informed moving target defense mechanism for cloud containers. ESCAPE models the interaction between attackers and their target containers as a "predator searching for a prey" search game. Live migration of Linux-containers (prey) is used to avoid attacks (predator) and failures. The entire process is guided by a novel host-based behavior-monitoring system that seamlessly monitors containers for indications of intrusions and attacks. To evaluate ESCAPE effectiveness, we simulated the attack avoidance process based on a mathematical model mimicking the prey-vs-predator search game. Simulation results show high container survival probabilities with minimal added overhead.

The emergence of Mobile Ad-hoc Clouds (MACs) promises more effective and collaborative elastic resource-infinite computing.However, the highly dynamic, mobile, heterogeneous, fractionized, and scattered nature of computing resources coupled with the isolated non-cooperative nature of current re

Mobile cloud computing (MCC) is evolving to efficiently and collaboratively utilize the ever-increasing pool of computing resources available on mobile devices. In such high dynamic networks, nodes are susceptible to failure for many reasons, for example, being out of battery or hijacked. Managing r

Today numerous infrastructure assets remain alarmingly susceptible to advanced, targeted cyber attacks. There is a need to construct trustworthy high-quality protection and defense solutions capable of securing such valuable assets. In our work, we realize such cyber trust through trace-resistant mo

Emerging technologies such as the Internet of Things generate huge amounts of network traffic and data which lead to significant challenges in a) ensuring availability of resources on-demand and b) recognizing emergent and abnormal behavior. Network traffic data exhibit spatiotemporal patterns. Lear

Modernizing our critical infrastructure often involves upgrades with Cyber-Physical Systems (CPS) to enhance efficiency, safety and reliability. New security and resilience challenges arise given the mission- and time-critical nature of CPS applications. Herby, we present CyPhyCARD (Cooperative Auto

Ubiquitous cyber systems and their supporting infrastructure impact productivity and quality of life immensely. Their penetration in our daily life increases the need for their enhanced resilience and for means to secure and protect them. One major threat is the software monoculture. Latest research

It is becoming increasingly challenging for the contemporary Internet to satisfy the explosion in networking services and applications with their widely diverse and dynamic QoS requirements and resource demands. For smarter networking management and operations, we hypothesize that next generation ne

Advances in next generations distributed cyberspace technologies are expected to evolve a global cyberspace marketplace for resource and services. In marketplaces, particularly with the autonomy of users, trading parties differ in many respects, for example their declared agendas, honesty, owned or

The complexity of handling multiple - often conflicting - tasks, coupled with the collaboration required by wireless sensor network (WSN) nodes to accomplish such tasks, exacerbate concerns about the effectiveness and longevity of the network. Handling multiple dynamic contexts and offering autonomic context-aware WSN management are severely limited by the network's resource constraints. This may affect the ability of sensors to join fully or partially in the missions of the network, restricting the quality of users' experience. Moreover, WSNs should work unattended and cannot assume global visibility or centralized services. Hence, we conceptualize next generation WSNs as autonomous distributed systems capable of dynamic and adaptive reconfiguration. Such networks should be capable of performing dynamic task allocation according to application demand, network conditions, and task context. In this paper we present an efficient distributed task allocation method for WSNs. We look at the task allocation problem in WSNs from a new perspective, where we show how it can be mapped to a clustering problem, and we leverage our previously proposed Affinity Propagation (AP) inspired clustering protocol to solve it. We contrast our approach against both optimal and naïve greedy solutions. By means of simulation, we show that our method is capable of achieving near-optimal results at only a fraction of the optimal solution cost.

Data sensing and retrieval in wireless sensor systems have a widespread application in areas such as security and surveillance monitoring, and command and control in battlefields. In query-based wireless sensor systems, a user would issue a query and expect a response to be returned within the deadline. While the use of fault tolerance mechanisms through redundancy improves query reliability in the presence of unreliable wireless communication and sensor faults, it could cause the energy of the system to be quickly depleted. Therefore, there is an inherent trade-off between query reliability versus energy consumption in query-based wireless sensor systems. In this paper, we develop adaptive fault-tolerant quality of service (QoS) control algorithms based on hop-by-hop data delivery utilizing “source” and “path” redundancy, with the goal to satisfy application QoS requirements while prolonging the lifetime of the sensor system. We develop a mathematical model for the lifetime of the sensor system as a function of system parameters including the “source” and “path” redundancy levels utilized. We discover that there exists optimal “source” and “path” redundancy under which the lifetime of the system is maximized while satisfying application QoS requirements. Numerical data are presented and validated through extensive simulation, with physical interpretations given, to demonstrate the feasibility of our algorithm design.

We foresee the need for dynamically clustering nodes in Wireless Sensor Networks (WSNs) according to a multitude of disparate co-existing contexts. To this end, we propose a distributed, low-overhead context-aware clustering protocol for WSNs. We employ Affinity Propagation (AP) for clustering nodes

In this paper, we present Adaptive Multi-Criteria Routing (AMCR), a novel routing approach for large-scale shared Sensor-Actuator NETworks (SANETs). Although many routing protocols have been proposed for wireless sensor networks, most of these protocols are designed with a specific application class or load pattern in mind. Furthermore, disparate concerns are usually woven within these protocols for optimization purposes. This limits the ability of these protocols to efficiently handle all the routing needs of shared SANET environments that may have different applications with different communication requirements. A novelty of the AMCR design is that it provides a truly generic routing protocol capable of exploiting the message semantics and adapting itself to the observed application characteristics in order to support the efficient operation of shared SANET platforms. AMCR provides descriptive criteria-based addressing of resources, and allows applications to publish their own resource criteria. It also provides seamless support for unicast/multicast/anycast/broadcast communication patterns. AMCR supports multi-criteria indexes to efficiently route complex queries. AMCR exploits the application-specific message semantics in routing, by allowing applications to create routing indexes for the most frequently targeted criteria. We also propose a mechanism for automatic adaptation of AMCR criteria indexes according to observed traffic patterns. The scalability and efficiency of AMCR is shown using analytical evaluation.

The 11 papers in this special issue on mission critical networking are divided into three categories: quality of service issues (three papers); security issues (four papers); and configuration and data collection issues (four papers).

Reputation management systems have been proposed as a cooperation enforcement solution in ad hoc networks. Typically, the functions of reputation management (evaluation, detection, and reaction) are carried out homogeneously across time and space. However, the dynamic nature of ad hoc networks causes node behavior to vary both spatially and temporally due to changes in local and network-wide conditions. When reputation management functions do not adapt to such changes, their effectiveness, measured in terms of accuracy (correct identification of node behavior) and promptness (timely identification of node misbehavior), may be compromised. We propose an adaptive reputation management system that realizes that changes in node behavior may be driven by changes in network conditions and that accommodates such changes by adapting its operating parameters. We introduce a time-slotted approach to allow the evaluation function to quickly and accurately capture changes in node behavior. We show how the duration of an evaluation slot can adapt according to the network's activity to enhance the system accuracy and promptness. We then show how the detection function can utilize a Sequential Probability Ratio Test (SPRT) to distinguish between cooperative and misbehaving neighbors. The SPRT adapts to changes in neighbors' behavior that are a by-product of changing network conditions, by using the node's own behavior as a benchmark. We compare our proposed solution to a nonadaptive system, showing the ability of our system to achieve high accuracy and promptness in dynamic environments. To the best of our knowledge, this is the first work to explore the adaptation of the reputation management functions to changes in network conditions.

In this paper, we develop and evaluate a new concept of adaptive optimal redundancy to efficiently provide wireless sensor network (WSN) users with QoS-aware information services. Our approach to satisfying application QoS requirements while maximizing the system lifetime is to determine dynamically the optimal level of redundancy at the ldquosourcerdquo and ldquopathrdquo levels in response to network dynamics and query QoS requirements on a query by query basis. We develop a mathematical model to analyze the performance characteristics of our proposed solution. The obtained results show that dynamically and adaptively identifying and managing optimal redundancy for per-hop data delivery lead to satisfying query QoS requirements in terms of reliability and timeliness, while maximizing the useful lifetime of WSNs. We validate the analytical results with extensive simulation.

The rapid advancement and the wide-spread use of the Internet and wireless communications in our professional endeavors and personal lives are making ubiquitous authenticated connectivity for mobile users indispensable. Individuals and groups may roam within a network or across networks, either in infrastructure or ad hoc mode. In any case, uninterrupted authenticated communication would be required for numerous applications, in particular real-time multimedia applications. In this paper, we propose an imbricated protocol suite for authentication in different mobility contexts at both the intra-and inter-network levels. To the best of our knowledge, this is the first comprehensive treatment of authentication in mobile networks. We demonstrate that our solution supports seamless secure mobility while incurring low overhead in the authentication process.

In most existing formulations of the problem of routing delay-constrained traffic, two important aspects have been largely overlooked: (i) delays caused by the MAC layer, and (ii) delays caused by packet queuing at the different nodes in a path. While the former aspect has been considered in some recent studies, the latter has yet to be investigated. In this paper, we present CARP, a context-aware protocol for routing delay-constrained traffic in sensor networks. CARP dynamically adapts each node's routing behavior to the current context of that node, i.e., its own routing load as well as the routing load of other nodes in its neighborhhod. We implemented CARP on top of TinyOS and conducted several experiments that confirmed CARP's efficiency in terms of routing delay-constrained traffic.

Clustering has become a crucial operation in wireless sensor networks (WSNs). Affinity propagation (AP) is a relatively new clustering technique that has been shown to possess several advantages over long-standing algorithms such as K-means, particularly in terms of quality of clustering and multi-criteria support. However, the original AP algorithm is computationally intensive making it unsuitable for clustering in WSNs. A hierarchical decentralized variation of AP (Hi-WAP) has been recently proposed to reduce the processing cost of AP while minimizing the potentially negative effect of distribution (due to the lack of a global view) on clustering quality. In this paper, we explore the suitability of Hi-WAP for clustering in WSNs. We employ the level of distortion and the processing time as evaluation metrics. We propose an extension to Hi-WAP, termed LAP; location-aware affinity propagation, where clustering is performed while being cognizant of nodes' locations. Simulation results reveal that LAP, in general, outperforms Hi-WAP. We further study the optimization of LAP parameter values with the objective of minimizing processing time while maintaining a desirable low level of distortion.

We present reliable adaptive service-driven efficient routing (muRACER), a routing protocol suite based on a novel service-oriented design for sensor-actuator networks where nodes expose their capabilities to applications as a service profile. A node's service profile consists of a set of services (i.e., sensing and actuation capabilities) that it provides and the quality-of-service (QoS) parameters associated with those services (delay, accuracy, freshness, etc.). muRACER uses an efficient service-aware routing approach that aggressively reduces downstream traffic (from the sink to the network's nodes) by translating service profiles into efficient paths for queries. To support QoS, muRACER dynamically adapts each node's routing behavior and service profile according to the current context of that node, i.e., number of pending queries and number and type of messages to be routed. Finally, muRACER improves end-to-end reliability through a scalable reputation-based approach in which each node is able to locally estimate the next hop of the most reliable path to the sink. Service- and context-aware reliable routing enhances the network's efficiency and effectiveness (satisfaction of applications' QoS requirements). We implemented muRACER on top of TinyOS and conducted several experiments that confirmed muRACER's ability with regard to each of its design objectives.

This paper proposes a requirements-driven security engineering approach for modeling, specifying, and analyzing application-specific security requirements that are formally derived into security design specifications preserving security requirements properties. The approach adopts and non-trivially extends the goal-oriented KAOS (Knowledge Acquisition in automated Specifications) framework developed by Lamsweerde to formally construct a complete, consistent, and clear security requirements model. The resulting model is then extended using the B method to produce security design specifications and further implementation while preserving requirements properties. In our approach, we firstly transform the KAOS requirements model to an abstract B model and secondly, we refine the model using B refinement mechanism to generate design specifications and implementation. This unique treatment of secure software engineering is systematic, constructive and considers security early in the development lifecycle while ensuring no loss of the security requirements properties of completeness, consistency and clarity at later development phases. Moreover, our approach allows for requirement traceability at the various phases of development.

The deployment of wireless networks is in permanent growth. To exploit their intrinsic mobility advantages, collaborative networks such as first responder networks (FRNs) have recently adopted wireless networking technologies, Albiet at a small scale. FRNs require the collaboration of heterogeneous and mobile groups. Impeding the wide-scale use of wireless networking in FRNs are the many security challenges like user authentication, information flow and wireless media management. In this paper, we propose a solution that enables authenticated communication among multiple FRNs which is especially needed during critical events such as intervention in disaster situations. Our solution uses a two-level hierarchical proxy signature to decentralize the authentication process across different administrative networks. To the best of our knowledge, this is the first construction of two-level signature delegation applied to wireless environments. Security and performance analysis and comparison with other works demonstrate the viability and advantages of our solution.

Most routing protocols for sensor-actuator networks (SANETs) are built under the assumption that nodes normally cooperate in forwarding each other's messages. In practice, this assumption is not realistic; SANETs are environments where nodes may or may not cooperate. For several reasons, a node may fail to operate as planned at deployment time. As a result, when actually deployed, protocols and applications may not be as efficient as expected. In this paper, we present TARP (Trust-Aware Routing Protocol), a routing protocol for sensor-actuator networks that exploits past nodes' routing behavior and links' quality to determine efficient paths. We implemented TARP in a TinyOS-based SANET and conducted several experiments to evaluate its performance. The obtained results confirmed that TARP achieves substantial improvements in terms of energy consumption and scalability.

We propose a secure routing architecture for mobile ad hoc networks (MANETs) called throughput-feedback (TUF) routing, which is resilient against a wide range of routing disruption denial-of-service (DoS) attacks. Unlike many existing solutions, TUF does not focus on a particular type of attack, but instead takes an approach that is fundamentally more general. TUF is a cross-layer technique that detects attacks at the transport layer but responds to attacks at the network layer. Because most routing disruption attacks cause a significant drop in end-to-end goodput, monitoring the goodput of a route at the transport layer can detect abnormalities in the network (e.g., node or link failures, DoS attacks, etc.). Once an abnormal event is detected, a route rebuilding process is initiated at the network layer to find a new route. Using analysis and simulation results, we show that the TUF architecture is effective in thwarting a wide range of attacks, including protocol-compliant (also known as "JellyFish") attacks.

When sensor networks overlap in their coverage areas, sensors in the common areas can be simultaneously shared among multiple networks. The shared sensors provide opportunities to support collaboration among sensor networks. Collaboration enriches functionality and enhances scalability and manageability of networked sensor systems, in particular those comprised of a large number of heterogeneous sensor networks deployed over a large area. Effective collaboration may require that various sensor networks share synchronized data replicas. In this paper, we propose a novel data replication mechanism suitable for the limited bandwidth of sensor networks. The scheme is comprised of off-line and in-line components and uses neural networks for scheduling of replication. Implementing a simple neural network requires minimal computational overhead feasible for use on a sensor node. To the best of our knowledge, this is the first scheme for synchronized replication in collaborative sensor network systems. Simulation results show that such neural-network-based approach provides near optimal scheduling and replication solutions while maintaining adaptability and low computational overhead.

In wireless sensor networks (WSNs), large populations of tiny sensor nodes probe the environment and report the collected data to a base-station(s) for processing. Due to the resource constraints, WSNs pose numerous and non-conventional design challenges compared to contemporary communication networks. One of the performance optimization techniques that have been recently proposed is to dynamically relocate the base-station closer to the sensors involved in heavy packet traffic in order to increase energy efficiency, packet delivery ratio and timeliness. In this paper, we argue that such relocation may jeopardize the base-station since it often moves the base-station too close to danger zones. We present STEER, an efficient safety-oriented relocation algorithm for base-stations that strives to protect the base-station while maintaining good network performance. The effectiveness of our algorithm is validated in a simulated environment.

Recent advances in wireless sensor networks (WSNs) are fueling the interest in their application in a wide variety of sensitive settings such as battlefield surveillance, border control, and infrastructure protection. Data confidentiality and authenticity are critical in these settings. However, the wireless connectivity, the absence of physical protection, the close interaction between WSNs and their physical environment, and the unattended deployment of WSNs make them highly vulnerable to node capture as well as a wide range of network-level attacks. Moreover, the constrained energy, memory, and computational capabilities of the employed sensor nodes limit the adoption of security solutions designed for wire-line and wireless networks. In this paper, we focus on the management of encryption keys in large-scale clustered WSNs. We propose a novel distributed key management scheme based on exclusion basis systems (EBS); a combinatorial formulation of the group key management problem. Our scheme is termed SHELL because it is scalable, hierarchical, efficient, location-aware, and light-weight. Unlike most existing key management schemes for WSNs, SHELL supports rekeying and, thus, enhances network security and survivability against node capture. SHELL distributes key management functionality among multiple nodes and minimizes the memory and energy consumption through trading off the number of keys and rekeying messages. In addition, SHELL employs a novel key assignment scheme that reduces the potential of collusion among compromised sensor nodes by factoring the geographic location of nodes in key assignment. Simulation results demonstrate that SHELL significantly boosts the network resilience to attacks while conservatively consuming nodes' resources

Abstract Securing sensor networks has received much attention in the last few years. In a typical field deployment, a sensor network self‐organizes, closely interacts with its physical environment, and works unattended possibly in a hostile environment such as a battlefield. In such environments, sensor networks are subject to node capture as well as a myriad of other attacks. Constrained energy, memory, and computational capabilities of sensor nodes mandate a clever design of security solutions to minimize overhead while maintaining secure communications over the lifespan of the network. In this paper, we propose a Dynamic Combinatorial Key management scheme, DCK, to provide efficient, scalable, and survivable dynamic keying in a clustered sensor network with a large number of sensor nodes. DCK employs the Exclusion‐Basis Systems (EBS) as the underlying framework for key management at both the cluster and the sensor node levels. DCK enhances network security by localizing cluster key management functions, thus, limiting the impact of sensor node capture to the attacked cluster. Within a cluster, DCK decouples key generation, assignment, and distribution, and distributes the key management tasks among cluster nodes. Simulation results show that DCK is efficient in terms of energy consumption and storage. Also, it significantly outperforms other dynamic keying schemes, in particular with regards to energy consumed in key refreshment and re‐keying after node capture. Copyright © 2006 John Wiley & Sons, Ltd.

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.

Due to the dynamic nature of wireless ad-hoc networks (WAHNs) and the multi-node involvement in most WAHN applications, group key management has been proposed for efficient support of secure communications. Exclusion basis systems (EBS) provide a framework for scalable and efficient group key management where the number of keys per node and the number of re-key messages can be relatively adjusted. EBS-based solutions, however, may suffer from collusion attacks, where a number of nodes may collaborate to reveal all system keys and consequently capture the network. In this paper we investigate the collusion problem in EBS and demonstrate that a careful assignment of keys to nodes reduces collusion. Since an optimal assignment is NP hard, we propose a location-based heuristic where keys are assigned to neighboring nodes depending on the Hamming distance between the strings of bits representing the used subset of the keys.

For ad hoc networks to realize their potential in commercial deployments, it is important that they incorporate adequate security measures. Selfish behavior of autonomous network nodes could greatly disrupt network operation. Such behavior should be discouraged, detected, and isolated. In this paper, we propose a reputation-based mechanism to detect and isolate selfish nodes in an ad hoc network. The proposed mechanism allows a node to autonomously evaluate the "reputation" of its neighbors based on the completion of the requested service. The underlying principle is that when a node forwards a packet through one of its neighbors, it holds that neighbor responsible for the correct delivery of the packet to the destination. Our mechanism is efficient and immune to node collusion since, unlike most contemporary mechanisms for reputation-based trust, it does not depend on exchanging reputation information among nodes. We also explore various reputation functions and report on their effectiveness in isolating selfish nodes and reducing false positives. Our simulation results demonstrate that the choice of the reputation function greatly impacts performance and that the proposed mechanism, with a carefully selected function, is successful in isolating selfish nodes while maintaining false positives at a reasonably low level.

Most of the current research in wireless sensor networks (WSNs) is constraint driven and focuses on optimizing the use of limited resources (e.g., power) at each sensor. While such constraints are important, there is a energy for more general performance metrics to assess the effectiveness of WSNs. There is also a need for a unified formal model that would enable comparison of different types of WSNs and provide a framework for WSN operations. We propose a new service-centric model that focuses on services provided by a WSN and views a WSN as a service provider. A WSN is modeled at different levels of abstraction. For each level, a set of services and a set of metrics are defined. Services and their interfaces are defined in a formal way to facilitate automatic composition of services, and enable interoperability and multitasking of WSNs at the different levels. A two-way mapping between two neighboring levels is then defined as a decomposition (from higher to lower level) and composition (from lower to higher level). A composite mapping between metrics at different levels connects high-level, mission-oriented metrics and low-level, capability-oriented metrics. The service-centric model consists of mission, network, region, sensor, and capability layers. Each layer has associated semantics that use lower level components as syntactic units (except for the capability layer). Within each layer there are four planes or functionality sets; communication, management, application, and generational learning. The combination of layers and planes enables a service-based visualization paradigm that can provide better understanding of the WSN. The service-centric model provides a holistic approach to measuring and presenting WSNs effectiveness. In addition, it presents a general and flexible framework in which various more specific WSN models can be represented and evaluated.

Secure group-based communication services are gaining momentum in wireless ad hoc networks (WAHNs). The efficiency and scalability of these services make them suitable for supporting the inherently collaborative computing and communications activities among peer WAHN nodes as well as the growing number of group-based WAHN applications. Key management, which is comprised of dynamic key generation, assignment, and distribution, is at the heart of secure group communications. This work proposes TKGS; an efficient threshold-based key generation scheme for open WAHNs based on collaborative reconstruction of key-generation keys. To mitigate node mal-behavior, a verifiable secret sharing technique is employed, where an (authenticated) dealer node is selected to collect a set number of valid shares and generate new administrative keys. While most existing key management schemes assume reliable and trusted nodes, TKGS provides a distributed solution that is resilient to node failure and mal-behavior. A major advantage of TKGS is its small overhead; collaborative key construction is done in less than two rounds with a very high probability of success.

Given the growing number of applications of wireless sensor networks, some recent research has focused on managing secure wireless communications in such networks. When a large group of sensors that typically are constrained in energy, computation and communication resource are deployed, efficient key management becomes critical. In this paper, we propose a new hierarchical key management scheme for wireless sensor networks based on a combinatorial optimization of the group key management problem. Our solution uses symmetric encryption and re-keying to support current, forward and backward secrecy. An important contribution of our solution is that it yields optimal results for the number of administrative keys per network granule and the number of re-key messages. We also present a mechanism for recovery from a node failure or compromise.

Computing and communications in wireless ad hoc networks (WAHNs) generally require collaboration among groups of peers. This, in addition to a growing number of group applications over WAHNs, have motivated research in secure group communication services as a means for efficient and secure communications in WAHNs. Key distribution is at the heart of secure group communications. Existing key distribution schemes, designed for infrastructure networks, tend to be inappropriate for the infrastructure-less WAHNs. Also, most of these schemes assume network-level multicast which is difficult to implement in WAHNs. We propose a new efficient and scalable combinatorial key distribution scheme (CKDS) to support secure group communications in WAHNs. CKDS partitions nodes over a virtual Cartesian key space and uses combinatorial exclusion basis systems for key distribution over application-level multicast. We employ a fully distributed unicast key distribution underlying a virtual application-level multicast infrastructure. Two variants of CKDS are proposed, namely, m-dimensional multicast and 2D multicast. Performance analysis shows that these schemes achieve lower network traffic overhead as well as lower computational overhead per node compared to other unicast key distribution schemes in WAHNs. We also show our scheme to be scalable with respect to both computational and storage needs.

Summary form only given. Most of the current research in wireless sensor networks (WSN, for short) is constraint driven and focuses on optimizing the use of limited resources (for example, power) at each sensor. While such constraints are important, there is a need for more general performance metrics describing the effectiveness of WSNs. There is also a need for a unified model that would enable comparison of different types of WSNs. We propose a new service-centric model that focuses on services provided by a WSN and their corresponding performance metrics. A WSN is modeled at different levels of abstraction. For each level, a set of services and a set of metrics are defined. A mapping between metrics at different levels relates high-level, mission-oriented metrics to low-level capability-oriented metrics. The proposed model consists of mission, network, region, sensor, and capability layers. Within each layer, four planes are identified, namely, communications, management, application, and generation learning. The proposed model provides a flexible, open framework for expressing and evaluating capabilities, functionalities, management, behavior, and evolution of a WSN. In addition, the proposed model provides a holistic approach to comparing WSNs and to measuring their effectiveness. The generation learning plane is unique in that it serves to extend the longevity of the network and to enhance the network effectiveness over time.

The network model assumed in this paper consists of tiny, energy-constrained, commodity sensors massively deployed alongside with one or more sink nodes that provide the interface to the outside world. The sensors in the network are initially anonymous and unaware of their location. Our main contribution is to propose a new robust and energy-efficient solution for secure operation of wireless sensor networks. The paper motivates a new paradigm where security is based upon using parameterized frequency hopping and cryptographic keys in a unified framework to provide differential security services for wireless sensor networks.

Computer supported cooperative work (CSCW) has the potential of providing the environment needed for groups of diverse users to cooperate to achieve their common goals. This potential has been under-utilized. One major obstacle is the lack of cooperation between CSCW systems and the underlying network services to accommodate the dynamic behavior of CSCW groups. Multicast routing presents a strong case where current network services are inadequate for the traffic generated in CSCW environments. We demonstrate the need for CSCW-specific multicast routing and present an integrated QoS architecture where a router QoS manager, on behalf of a multicast routing manager, negotiates with host and CSCW-specific QoS managers for efficient resource utilization and guaranteed QoS delivery. The multicast routing manager switches between routing trees or algorithms as guaranteed by the changes in the characteristics and requirements of the CSCW systems running at the hosts. We discuss an aspect-oriented programming approach to the efficient description and flexible implementation of adaptive application and network protocol behavior.

Summary form only given. Computing and communications technologies have revolutionized the methods for creation, reproduction, and dissemination of copyrighted multimedia information. The demand on this electronic information increases rapidly as developers and users migrate to computer supported cooperative work, or CSCW, environments. Central to CSCW environments is information sharing both at the intra- as well as the inter-group levels. The electronic circulation of copyrighted information among group members poses numerous problems. We can identify a set of requirements for the electronic circulation of copyrighted objects in CSCW environments. We present a novel approach to satisfy these requirements. Our approach is to commercialize autonomous inter-entity sharing in order to discourage unauthorized reproduction activities and promote autonomous sharing of copyrighted information in group activities.