In mobile-beacon assisted sensor localization, beacon mobility scheduling aims to determine the best beacon trajectory so that each sensor receives sufficient beacon signals and becomes localized ...with minimum delay. We propose a novel DeteRministic dynamic bEAcon Mobility Scheduling (DREAMS) algorithm, without requiring any prior knowledge of the sensory field. In this algorithm, the beacon trajectory is defined as the track of Depth-First Traversal (DFT) of the network graph, thus deterministic. The mobile beacon performs DFT dynamically, under the instruction of nearby sensors on the fly. It moves from sensor to sensor in an intelligent heuristic manner according to Received Signal Strength (RSS)-based distance measurements. We prove that DREAMS guarantees full localization (every sensor is localized) when the measurements are noise-free, and derive the upper bound of beacon total moving distance in this case. Then, we suggest to apply node elimination and Local Minimum Spanning Tree (LMST) to shorten beacon tour and reduce delay. Further, we extend DREAMS to multibeacon scenarios. Beacons with different coordinate systems compete for localizing sensors. Loser beacons agree on winner beacons' coordinate system, and become cooperative in subsequent localization. All sensors are finally localized in a commonly agreed coordinate systems. Through simulation we show that DREAMS guarantees full localization even with noisy distance measurements. We evaluate its performance on localization delay and communication overhead in comparison with a previously proposed static path-based scheduling method.
We propose a radically new family of geometric graphs, i.e., Hypocomb (HC), Reduced Hypocomb (RHC), and Local Hypocomb (LHC). HC and RHC are extracted from a complete graph; LHC is extracted from a ...Unit Disk Graph (UDG). We analytically study their properties including connectivity, planarity, and degree bound. All these graphs are connected (provided that the original graph is connected) planar. Hypocomb has unbounded degree while Reduced Hypocomb and Local Hypocomb have maximum degree 6 and 8, respectively. To our knowledge, Local Hypocomb is the first strictly localized, degree-bounded planar graph computed using merely 1-hop neighbor position information. We present a construction algorithm for these graphs and analyze its time complexity. Hypocomb family graphs are promising for wireless ad hoc networking. We report our numerical results on their average degree and their impact on FACE routing. We discuss their potential applications and pinpoint some interesting open problems for future research.
Telecommunication software systems, containing security vulnerabilities, continue to be created and released to consumers. We need to adopt improved software engineering practices to reduce the ...security vulnerabilities in modern systems. Contracts can provide a useful mechanism for the identification, tracking, and validation of security vulnerabilities. In this work, we propose a new contract-based security assertion monitoring framework (CB_SAMF) that is intended to reduce the number of security vulnerabilities that are exploitable across multiple software layers, and to be used in an enhanced systems development life cycle (SDLC). We show how contract-based security assertion monitoring can be achieved in a live environment on Linux. Through security activities integrated into the SDLC we can identify potential security vulnerabilities in telecommunication systems, which in turn are used for the creation of contracts defining security assertions. Our contract model is then applied, as runtime probes, against two common security related vulnerabilities in the form of a buffer overflow and a denial of service.
Secure key establishment in wireless sensor networks has been shown to be efficient. For sake of computation power, pre- distribution of symmetric keys is recommended. In such schemes, a set S of ...keys is used and each deployed node knows a subset of S. However, the capture of nodes can quickly lead to the corruption of a significant part of the network and solutions like multi-deployment have been proposed. In multi-deployment schemes, sets of nodes – using different key sets – are sequentially deployed that limits the impact of the capture of nodes. In this paper, we consider the problem of connectivity of single deployment in regards to the size of key sets. We show that connectivity guaranteed solutions lead to network vulnerability when nodes are captured. Then we evaluate network robustness of different schemes.
We propose a radically new family of geometric graphs, i.e., Hypocomb, Reduced Hypocomb and Local Hypocomb. The first two are extracted from a complete graph; the last is extracted from a Unit Disk ...Graph (UDG). We analytically study their properties including connectivity, planarity and degree bound. All these graphs are connected (provided the original graph is connected) planar. Hypocomb has unbounded degree while Reduced Hypocomb and Local Hypocomb have maximum degree 6 and 8, respectively. To our knowledge, Local Hypocomb is the first strictly-localized, degree-bounded planar graph computed using merely 1-hop neighbor position information. We present a construction algorithm for these graphs and analyze its time complexity. Hypocomb family graphs are promising for wireless ad hoc networking. We report our numerical results on their average degree and their impact on FACE routing. We discuss their potential applications and some open problems.
This paper investigates the compositional properties of reusable software components defined with explicit dependencies and behavioural contracts expressing rely-guarantee specifications in the form ...of communication traces. In this setting, connection of components through their matching ports is indeed compositional and yields a new component or
composite that respects its constituents’ contracts. Thus the behaviour of the composite is computed from the behaviours of its constituents and is known to conform to the contracts without any new proof.
On-device control flow verification for Java programs Fontaine, Arnaud; Hym, Samuel; Simplot-Ryl, Isabelle
Proceedings of the Third international conference on Engineering secure software and systems,
02/2011
Conference Proceeding
Recenzirano
While mobile devices have become ubiquitous and generally multi-application capable, their operating systems provide few high level mechanisms to protect services offered by application vendors ...against potentially hostile applications coexisting on the device. In this paper, we tackle the issue of controlling application interactions including collusion in Java-based systems running on open, constrained devices such as smart cards or mobile phones. We present a model specially designed to be embedded in constrained devices to verify on-device at loading-time that interactions between applications abide by the security policies of each involved application without resulting in run-time computation overheads; this model deals with application (un)installations and policy changes in an incremental fashion. We sketch the application of our approach and its security enhancements on a multi-application use case for GlobalPlatform/Java Card smart cards.
This paper investigates the compositional properties of reusable software components defined with explicit dependencies and behavioural contracts expressing rely-guarantee specifications in the form ...of communication traces. In this setting, connection of components through their matching ports is indeed compositional and yields a new component or composite that respects its constituents’ contracts. Thus the behaviour of the composite is computed from the behaviours of its constituents and is known to conform to the contracts without any new proof.
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