Further results on strongbox secured secret sharing schemes

We extend our earlier work on ways in which defining sets of combinatorial designs can be used to create secret sharing schemes. We give an algorithm for classifying defining sets or designs according to their security properties and summarise the results of this algorithm for many small designs. Finally, we discuss briefly how defining sets can be applied to variations of the basic secret sharing scheme.

Information flow analysis for fail-secure devices

Information security devices must preserve security properties even in the presence of faults. This in turn requires a rigorous evaluation of the system behaviours resulting from component failures, especially how such failures affect information flow. We introduce a compositional method of static analysis for fail-secure behaviour. Our method uses reachability matrices to identify potentially undesirable information flows based on the fault modes of the system's components.

Verifying abstract information flow properties in fault tolerant security devices

The verification of information flow properties of security devices is difficult because it involves the analysis of schematic diagrams, artwork, embedded software, etc. In addition, a typical security device has many modes, partial information flow, and needs to be fault tolerant. We propose a new approach to the verification of such devices based upon checking abstract information flow properties expressed as graphs. This approach has been implemented in software, and successfully used to find possible paths of information flow through security devices.

The psychometric properties of a psychosis screen in a correctional setting

Many people who go to gaol are mentally ill. Remandees, prisoner receptions or people in jails have a substantially higher rate of severe mental disorder than other prisoners and the general population. There are no completely satisfactory ways to screen for psychosis and few existing screening questionnaires are available for use in correctional establishments. The Screening Instrument for Psychosis (PS) was developed in the context of the Australian Mental Health Survey: Study of Low Prevalence Disorders. It can help indicate whether a person should be referred to mental health professional for a diagnostic evaluation and possible treatment and/or diversion. We trialled the PS in a high security remand and reception centre. Measures of validity and reliability are reported. (c) 2006 Published by Elsevier Inc.

A Z based approach to verifying security protocols

Security protocols preserve essential properties, such as confidentiality and authentication, of electronically transmitted data. However, such properties cannot be directly expressed or verified in contemporary formal methods. Via a detailed example, we describe the phases needed to formalise and verify the correctness of a security protocol in the state-oriented Z formalism.