Enabling the Internet White Pages Service -- the Directory Guardian

The Internet White Pages Service (IWPS) has been slow to materialise for many reasons. One of them is the security concerns that organisations have, over allowing the public to gain access to either their Intranet or their directory database. The Directory Guardian is a firewall application proxy for X.500 and LDAP protocols that is designed to alleviate these fears. Sitting in the firewall system, it filters directory protocol messages passing into and out of the Intranet, allowing security administrators to carefully control the amount of directory information that is released to the outside world. This paper describes the design of our Guardian system, and shows how relatively easy it is to configure its filtering capabilities. Finally the paper describes the working demonstration of the Guardian that was built for the 1997 World Electronic Messaging Association directory challenge. This linked the WEMA directory to the NameFLOWParadise Internet directory, and demonstrated some of the powerful filtering capabilities of the Guardian

Coping with Poorly Understood Domains: the Example of Internet Trust

The notion of trust, as required for secure operations over the Internet, is important for ascertaining the source of received messages. How can we measure the degree of trust in authenticating the source? Knowledge in the domain is not established, so knowledge engineering becomes knowledge generation rather than mere acquisition. Special techniques are required, and special features of KBS software become more important than in conventional domains. This paper generalizes from experience with Internet trust to discuss some techniques and software features that are important for poorly understood domains

Providing secure remote access to legacy applications

While the widespread adoption of Internet and Intranet technology has been one of the exciting developments of recent years, many hospitals are finding that their data and legacy applications do not naturally fit into the new methods of dissemination. Existing applications often rely on isolation or trusted networks for their access control or security, whereas untrusted wide area networks pay little attention to the authenticity, integrity or confidentiality of the data they transport. Many hospitals do not have the resources to develop new ''network-ready'' versions of existing centralised applications. In this paper, we examine the issues that must be considered when providing network access to an existing health care application, and we describe how we have implemented the proposed solution in one healthcare application namely the diabetic register at Hope Hospital. We describe the architecture that allows remote access to the legacy application, providing it with encrypted communications and strongly authenticated access control but without requiring any modifications to the underlying application. As well as comparing alternative ways of implementing such a system, we also consider issues relating to usability and manageability, such as password management

Merging and Extending the PGP and PEM Trust Models - the ICE-TEL Trust Model

The ICE-TEL project is a pan-European project that is building an Internet X.509 based certification infrastructure throughout Europe, plus several secure applications that will use it. This paper describes the trust model that is being implemented by the project. A trust model specifies the means by which a user may build trust in the assertion that a remote user is really who he purports to be (authentication) and that he does in fact have a right to access the service or information that he is requesting (authorization). The ICE-TEL trust model is based on a merging of and extensions to the existing Pretty Good Privacy (PGP) web of trust and Privacy Enhanced Mail (PEM) hierarchy of trust models, and is called a web of hierarchies trust model. The web of hierarchies model has significant advantages over both of the previous models, and these are highlighted here. The paper further describes the way that the trust model is enforced through some of the new extensions in the X.509 V3 certificates, and gives examples of its use in different scenarios

Initial Experiences of Building Secure Access to Patient Confidential Data via the Internet

A project to enable health care professionals (GPs, practice nurses and diabetes nurse specialists) to access, via the Internet, confidential patient data held on a secondary care (hospital) diabetes information system, has been implemented. We describe the application that we chose to distribute (a diabetes register); the security mechanisms we used to protect the data (a public key infrastructure with strong encryption and digitally signed messages, plus a firewall); the reasons for the implementation decisions we made; the validation testing that we performed and the preliminary results of the pilot implementation

A developmental study of representation and strategy in children's solutions to problems involving chance and probability

The problems used in the study involve two collections of elements of two colours. The proportions of elements of each colour in each of the collections is varied, and the way children reason when asked which collection they would prefer in order to gamble for a specified outcome is investigated in three situations: (a) The elements are beads to be drawn from boxes. (72 subjects aged 5-10 years, 48 subjects aged 11-14 years). (b) The elements are single segments marked on circles of different sizes with pointers to be spun. (72 subjects aged 6-11 years). (c) The elements are similar to (b), but marked into separate pieces to allow comparison by counting. (60 subjects, aged 6-10 years). Four possible ways of solving such problems are outlined: Method 1: Guessing, alternating choices and other irrelevant methods. Method 2: Comparing the amounts of the target elements in each collection, and choosing the collection with the greater amount. Method 3: Comparing the differences between the amount of target and non-target elements in each collection, and choosing the collection with the most favourable difference. Method 4: Comparing the proportions of target and non-target elements in each collection, and choosing the collection with the most favourable proportion. Within the main age range investigated. (6-10 years), methods 1-3 are found to form a developmental sequence, in situation (a), whereas in situations (b) and (c) the predominant developmental sequence is from Method 1 to Method 2 only. It is argued that this can be explained by considering the methods of quantification used by subjects in each situation. (A summary of the way in which the main themes are developed in the thesis is given at the end of the thesis.

Orientation-sensitivity to facial features explains the Thatcher illusion

The Thatcher illusion provides a compelling example of the perceptual cost of face inversion. The Thatcher illusion is often thought to result from a disruption to the processing of spatial relations between face features. Here, we show the limitations of this account and instead demonstrate that the effect of inversion in the Thatcher illusion is better explained by a disruption to the processing of purely local facial features. Using a matching task, we found that participants were able to discriminate normal and Thatcherized versions of the same face when they were presented in an upright orientation, but not when the images were inverted. Next, we showed that the effect of inversion was also apparent when only the eye region or only the mouth region was visible. These results demonstrate that a key component of the Thatcher illusion is to be found in orientation-specific encoding of the expressive features (eyes and mouth) of the face

A first impression of the future

Funding Information: This research was supported by Australian Research Council (ARC) Discovery Early Career Research Award DE190101043 (to C.S.), an Experimental Psychology Society Small Research grant (to C.S.) and an ARC Discovery Award DP170104602 (to C.S. and A.Y). ACKNOWLEDGMENTS We thank Dr Jemma Collova from the School of Indigenous Studies, University of Western Australia, for helpful feedback on a draft.Peer reviewedPublisher PD