The Value of User-Visible Internet Cryptography

Cryptographic mechanisms are used in a wide range of applications, including email clients, web browsers, document and asset management systems, where typical users are not cryptography experts. A number of empirical studies have demonstrated that explicit, user-visible cryptographic mechanisms are not widely used by non-expert users, and as a result arguments have been made that cryptographic mechanisms need to be better hidden or embedded in end-user processes and tools. Other mechanisms, such as HTTPS, have cryptography built-in and only become visible to the user when a dialogue appears due to a (potential) problem. This paper surveys deployed and potential technologies in use, examines the social and legal context of broad classes of users, and from there, assesses the value and issues for those users

Integrating BON and Object-Z.

A significant limitation with object-oriented formal specification languages, such as Object-Z, is that they lack development and management processes, which can be used to guide the production of reliable, robust object-oriented systems. An integration of an object-oriented methodology, BON, and Object-Z is presented in order to add an industrially validated development process to Object-Z. An extensible CASE tool for BON is also described that supports the integration with an Object-Z code generation engine

Promoting Physical Activity in Low Income African Americans: Project LAPS

Low income African Americans are at increased risk for physical inactivity and related chronic illnesses. Thus, effective interventions are needed to address these health disparities. The current study examined the efficacy of a home-based physical activity intervention among a low income African American sample with high rates of chronic illnesses (obesity, hypertension, diabetes, high cholesterol). Participants (n=214) were randomly assigned to either the home-based physical activity intervention (self-help print materials, five monthly newsletters, two telephone counseling sessions) or an attention control condition, which promoted healthy diet. Results indicated that the intervention did not produce significantly greater increases in physical activity from baseline to six months than the control group. Lessons learned from the current study include the importance of using proactive retention strategies with low income African American participants and taking into consideration the cultural relevance of the intervention

Behaviour-Based Cheat Detection in Multiplayer Games with Event-B

Cheating is a key issue in multiplayer games as it causes unfairness which reduces legitimate users' satisfaction and is thus detrimental to game revenue. Many commercial solutions prevent cheats by reacting to speci c implementations of cheats. As a result, they respond more slowly to fast-changing cheat techniques. This work proposes a framework using Event-B to describe and detect cheats from server-visible game behaviours. We argue that this cheat detection is more resistant to changing cheat technique

Metamodel-based model conformance and multiview consistency checking

Model-driven development, using languages such as UML and BON, often makes use of multiple diagrams (e.g., class and sequence diagrams) when modeling systems. These diagrams, presenting different views of a system of interest, may be inconsistent. A metamodel provides a unifying framework in which to ensure and check consistency, while at the same time providing the means to distinguish between valid and invalid models, that is, conformance. Two formal specifications of the metamodel for an object-oriented modeling language are presented, and it is shown how to use these specifications for model conformance and multiview consistency checking. Comparisons are made in terms of completeness and the level of automation each provide for checking multiview consistency and model conformance. The lessons learned from applying formal techniques to the problems of metamodeling, model conformance, and multiview consistency checking are summarized