An administrative model for UCON

UCON is an emerging access control framework that lacks an administration model. In this paper we define the problem of administration and propose a novel administrative model. At the core of this model is the concept of attribute, which is also the central component of UCON. In our model, attributes are created by the assertions of subjects, which ascribe properties/rights to other subjects or objects. Through such a treatment of attributes, administration capabilities can be delegated from one subject to another and as a consequence UCON is improved in three aspects. First, immutable attributes that are currently considered as external to the model can be incorporated and thereby treated as mutable at- tributes. Second, the current arbitrary categorisation of users (as modifiers of attributes), to system and administrator can be removed. Attributes and objects are only modifiable by those who possess administration capability over them. Third, the delegation of administration over objects and properties that is not currently expressible in UCON is made possible.

Towards authorisation models for secure information sharing : a survey and research agenda

This article presents a survey of authorisation models and considers their ‘fitness-for-purpose’ in facilitating information sharing. Network-supported information sharing is an important technical capability that underpins collaboration in support of dynamic and unpredictable activities such as emergency response, national security, infrastructure protection, supply chain integration and emerging business models based on the concept of a ‘virtual organisation’. The article argues that present authorisation models are inflexible and poorly scalable in such dynamic environments due to their assumption that the future needs of the system can be predicted, which in turn justifies the use of persistent authorisation policies. The article outlines the motivation and requirement for a new flexible authorisation model that addresses the needs of information sharing. It proposes that a flexible and scalable authorisation model must allow an explicit specification of the objectives of the system and access decisions must be made based on a late trade-off analysis between these explicit objectives. A research agenda for the proposed Objective-based Access Control concept is presented.

Evaluation of aerial remote sensing techniques for vegetation management in power line corridors

The following paper presents an evaluation of airborne sensors for use in vegetation management in powerline corridors. Three integral stages in the management process are addressed including, the detection of trees, relative positioning with respect to the nearest powerline and vegetation height estimation. Image data, including multi-spectral and high resolution, are analyzed along with LiDAR data captured from fixed wing aircraft. Ground truth data is then used to establish the accuracy and reliability of each sensor thus providing a quantitative comparison of sensor options. Tree detection was achieved through crown delineation using a Pulse-Coupled Neural Network (PCNN) and morphologic reconstruction applied to multi-spectral imagery. Through testing it was shown to achieve a detection rate of 96%, while the accuracy in segmenting groups of trees and single trees correctly was shown to be 75%. Relative positioning using LiDAR achieved a RMSE of 1.4m and 2.1m for cross track distance and along track position respectively, while Direct Georeferencing achieved RMSE of 3.1m in both instances. The estimation of pole and tree heights measured with LiDAR had a RMSE of 0.4m and 0.9m respectively, while Stereo Matching achieved 1.5m and 2.9m. Overall a small number of poles were missed with detection rates of 98% and 95% for LiDAR and Stereo Matching.

Using Ownership to Reason About Inherent Parallelism in Object-Oriented Programs

With the emergence of multi-cores into the mainstream, there is a growing need for systems to allow programmers and automated systems to reason about data dependencies and inherent parallelismin imperative object-oriented languages. In this paper we exploit the structure of object-oriented programs to abstract computational side-effects. We capture and validate these effects using a static type system. We use these as the basis of sufficient conditions for several different data and task parallelism patterns. We compliment our static type system with a lightweight runtime system to allow for parallelization in the presence of complex data flows. We have a functioning compiler and worked examples to demonstrate the practicality of our solution.

Correctness ensuring process configuration : an approach based on partner synthesis

A configurable process model describes a family of similar process models in a given domain. Such a model can be configured to obtain a specific process model that is subsequently used to handle individual cases, for instance, to process customer orders. Process configuration is notoriously difficult as there may be all kinds of interdependencies between configuration decisions.} In fact, an incorrect configuration may lead to behavioral issues such as deadlocks and livelocks. To address this problem, we present a novel verification approach inspired by the ``operating guidelines'' used for partner synthesis. We view the configuration process as an external service, and compute a characterization of all such services which meet particular requirements using the notion of configuration guideline. As a result, we can characterize all feasible configurations (i.\,e., configurations without behavioral problems) at design time, instead of repeatedly checking each individual configuration while configuring a process model.

One-time-password-authenticated key exchange

To reduce the damage of phishing and spyware attacks, banks, governments, and other security-sensitive industries are deploying one-time password systems, where users have many passwords and use each password only once. If a single password is compromised, it can be only be used to impersonate the user once, limiting the damage caused. However, existing practical approaches to one-time passwords have been susceptible to sophisticated phishing attacks. ---------- We give a formal security treatment of this important practical problem. We consider the use of one-time passwords in the context of password-authenticated key exchange (PAKE), which allows for mutual authentication, session key agreement, and resistance to phishing attacks. We describe a security model for the use of one-time passwords, explicitly considering the compromise of past (and future) one-time passwords, and show a general technique for building a secure one-time-PAKE protocol from any secure PAKE protocol. Our techniques also allow for the secure use of pseudorandomly generated and time-dependent passwords.

Predicate-based key exchange

We provide the first description of and security model for authenticated key exchange protocols with predicate-based authentication. In addition to the standard goal of session key security, our security model also provides for credential privacy: a participating party learns nothing more about the other party's credentials than whether they satisfy the given predicate. Our model also encompasses attribute-based key exchange since it is a special case of predicate-based key exchange.---------- We demonstrate how to realize a secure predicate-based key exchange protocol by combining any secure predicate-based signature scheme with the basic Diffie-Hellman key exchange protocol, providing an efficient and simple solution.

Evolutionary game design

Abstract—It is easy to create new combinatorial games but more difficult to predict those that will interest human players. We examine the concept of game quality, its automated measurement through self-play simulations, and its use in the evolutionary search for new high-quality games. A general game system called Ludi is described and experiments conducted to test its ability to synthesize and evaluate new games. Results demonstrate the validity of the approach through the automated creation of novel, interesting, and publishable games. Index Terms—Aesthetics, artificial intelligence (AI), combinatorial game, evolutionary search, game design.

Efficient and accurate retrieval of business process models through indexing

Recent years have seen an increased uptake of business process management technology in industries. This has resulted in organizations trying to manage large collections of business process models. One of the challenges facing these organizations concerns the retrieval of models from large business process model repositories. For example, in some cases new process models may be derived from existing models, thus finding these models and adapting them may be more effective than developing them from scratch. As process model repositories may be large, query evaluation may be time consuming. Hence, we investigate the use of indexes to speed up this evaluation process. Experiments are conducted to demonstrate that our proposal achieves a significant reduction in query evaluation time.

Mitigating sandwich attacks against a secure key management scheme in wireless sensor networks for PCS/SCADA

Alzaid et al. proposed a forward & backward secure key management scheme in wireless sensor networks for Process Control Systems (PCSs) or Supervisory Control and Data Acquisition (SCADA) systems. The scheme, however, is still vulnerable to an attack called the sandwich attack that can be launched when the adversary captures two sensor nodes at times t1 and t2, and then reveals all the group keys used between times t1 and t2. In this paper, a fix to the scheme is proposed in order to limit the vulnerable time duration to an arbitrarily chosen time span while keeping the forward and backward secrecy of the scheme untouched. Then, the performance analysis for our proposal, Alzaid et al.’s scheme, and Nilsson et al.’s scheme is given.

A multicast routing scheme for efficient safety message dissemination in VANET

Vehicular ad hoc network (VANET) is a wireless ad hoc network that operates in a vehicular environment to provide communication between vehicles. VANET can be used by a diverse range of applications to improve road safety. Cooperative collision warning system (CCWS) is one of the safety applications that can provide situational awareness and warning to drivers by exchanging safety messages between cooperative vehicles. Currently, the routing strategies for safety message dissemination in CCWS are scoped broadcast. However, the broadcast schemes are not efficient as a warning message is sent to a large number of vehicles in the area, rather than only the endangered vehicles. They also cannot prioritize the receivers based on their critical time to avoid collision. This paper presents a more efficient multicast routing scheme that can reduce unnecessary transmissions and also use adaptive transmission range. The multicast scheme involves methods to identify an abnormal vehicle, the vehicles that may be endangered by the abnormal vehicle, and the latest time for each endangered vehicle to receive the warning message in order to avoid the danger. We transform this multicast routing problem into a delay-constrained minimum Steiner tree problem. Therefore, we can use existing algorithms to solve the problem. The advantages of our multicast routing scheme are mainly its potential to support various road traffic scenarios, to optimize the wireless channel utilization, and to prioritize the receivers.

On ensuring continuity of mobile communications in a disaster environment

Natural disasters and deliberate, willful damage to telecommunication infrastructure can result in a loss of critical voice and data services. This loss of service hinders the ability for efficient emergency response and can cause delays leading to loss of life. Current mobile devices are generally tied to one network operator. When a disaster is of significant impact, that network operator cannot be relied upon to provide service and coverage levels that would normally exist. While some operators have agreements with other operators to share resources (such as network roaming) these agreements are contractual in nature and cannot be activated quickly in an emergency. This paper introduces Fourth Generation (4G) wireless networks. 4G networks are highly mobile and heterogeneous, which makes 4G networks highly resilient in times of disaster.

Protecting the protectors : legal liabilities from the use of Web 2.0 for Australian disaster response

The traditional model for information dissemination in disaster response is unidirectional from official channels to the public. However recent crises in the US, such as Hurricane Katrina and the Californian Bushfires show that civilians are now turning to Web 2.0 technologies as a means of sharing disaster related information. These technologies present enormous potential benefits to disaster response authorities that cannot be overlooked. In Australia, the Victorian Bushfires Royal Commission has recently recommended that Australian disaster response authorities utilize information technologies to improve the dissemination of disaster related, bushfire information. However, whilst the use of these technologies has many positive attributes, potential legal liabilities for disaster response authorities arise. This paper identifies some potential legal liabilities arising from the use of Web 2.0 technologies in disaster response situations thereby enhancing crisis related information sharing by highlighting legal concerns that need to be addressed.

Dragline automation: experimental evaluation through productivity trial

Since 1993 we have been working on the automation of dragline excavators, the largest earthmoving machines that exist. Recently we completed a large-scale experimental program where the automation system was used for production purposes over a two week period and moved over 200,000 tonnes of overburden. This is a landmark achievement in the history of automated excavation. In this paper we briefly describe the robotic system and how it works cooperatively with the machine operator. We then describe our methodology for gauging machine performance, analyze results from the production trial and comment on the effectiveness of the system that we have created. © Springer-Verlag Berlin Heidelberg 2006.