Attributes and Dimensions of Trust in Secure Systems

What is it to be trusted? This is an important question as trust is increasingly placed in a system and the degree to which a system is trusted is increasingly being assessed. However, there are issues with how related terms are used. Many definitions focus on one attribute of trust (typically behaviour) preventing that definition from being used for other attributes (e.g., identity). This is confused further by conflating what trustors measure about a trustee and what conclusions a trustor reaches about a trustee. Therefore, in this paper we present definitions of measures (trustiness and trustworthiness) and conclusions (trusted and trustworthy). These definitions are general and do not refer to a specific attribute allowing them to be used with arbitrary attributes which are being assessed (e.g., identity, behaviour, limitation, execution, correctness, data, environment). In addition, in order to demonstrate the complexities of describing if a trustee is designated as trusted or trustworthy, a set of dimensions are defined to describe attributes (time, scale, proactive/reactive, strength, scope, source). Finally, an example system is classified using these attributes and their dimensions in order to highlight the complexities of describing a system as holistically trusted or trustworthy

The effects of cyber readiness and response on human trust in self driving cars

The potential for self-driving cars (SDCs) and their connected infrastructure to be cyber attacked is a growing concern. Aside from material losses, an adverse cyber experience is likely to undermine human trust – a key contributing factor in the uptake and use of automated technologies such as SDCs. Preparing for such an event and responding appropriately when it happens is likely to play a key role in not only reducing the impact of a cyber attack but also in trusting the technology. This paper presents data from an initial experiment that explores whether the level of cyber readiness and type of response from an SDC company – who are assumed to be ultimately responsible for the SDC and most likely to be blamed for the incident – impacts trust and blame. Using Simulation Software Generated Animations, early findings provide an indication that trust is likely to be greater in SDCs and their respective company when more mature cyber security practices - in terms of level of readiness and type of response to a cyber attack - are adopted. A company with more mature cyber security practices (who are seemingly more trusted) is likely to be blamed less in the event of a cyber attack

Health-status outcomes with invasive or conservative care in coronary disease

BACKGROUND In the ISCHEMIA trial, an invasive strategy with angiographic assessment and revascularization did not reduce clinical events among patients with stable ischemic heart disease and moderate or severe ischemia. A secondary objective of the trial was to assess angina-related health status among these patients. METHODS We assessed angina-related symptoms, function, and quality of life with the Seattle Angina Questionnaire (SAQ) at randomization, at months 1.5, 3, and 6, and every 6 months thereafter in participants who had been randomly assigned to an invasive treatment strategy (2295 participants) or a conservative strategy (2322). Mixed-effects cumulative probability models within a Bayesian framework were used to estimate differences between the treatment groups. The primary outcome of this health-status analysis was the SAQ summary score (scores range from 0 to 100, with higher scores indicating better health status). All analyses were performed in the overall population and according to baseline angina frequency. RESULTS At baseline, 35% of patients reported having no angina in the previous month. SAQ summary scores increased in both treatment groups, with increases at 3, 12, and 36 months that were 4.1 points (95% credible interval, 3.2 to 5.0), 4.2 points (95% credible interval, 3.3 to 5.1), and 2.9 points (95% credible interval, 2.2 to 3.7) higher with the invasive strategy than with the conservative strategy. Differences were larger among participants who had more frequent angina at baseline (8.5 vs. 0.1 points at 3 months and 5.3 vs. 1.2 points at 36 months among participants with daily or weekly angina as compared with no angina). CONCLUSIONS In the overall trial population with moderate or severe ischemia, which included 35% of participants without angina at baseline, patients randomly assigned to the invasive strategy had greater improvement in angina-related health status than those assigned to the conservative strategy. The modest mean differences favoring the invasive strategy in the overall group reflected minimal differences among asymptomatic patients and larger differences among patients who had had angina at baseline

Initial invasive or conservative strategy for stable coronary disease

BACKGROUND Among patients with stable coronary disease and moderate or severe ischemia, whether clinical outcomes are better in those who receive an invasive intervention plus medical therapy than in those who receive medical therapy alone is uncertain. METHODS We randomly assigned 5179 patients with moderate or severe ischemia to an initial invasive strategy (angiography and revascularization when feasible) and medical therapy or to an initial conservative strategy of medical therapy alone and angiography if medical therapy failed. The primary outcome was a composite of death from cardiovascular causes, myocardial infarction, or hospitalization for unstable angina, heart failure, or resuscitated cardiac arrest. A key secondary outcome was death from cardiovascular causes or myocardial infarction. RESULTS Over a median of 3.2 years, 318 primary outcome events occurred in the invasive-strategy group and 352 occurred in the conservative-strategy group. At 6 months, the cumulative event rate was 5.3% in the invasive-strategy group and 3.4% in the conservative-strategy group (difference, 1.9 percentage points; 95% confidence interval [CI], 0.8 to 3.0); at 5 years, the cumulative event rate was 16.4% and 18.2%, respectively (difference, 121.8 percentage points; 95% CI, 124.7 to 1.0). Results were similar with respect to the key secondary outcome. The incidence of the primary outcome was sensitive to the definition of myocardial infarction; a secondary analysis yielded more procedural myocardial infarctions of uncertain clinical importance. There were 145 deaths in the invasive-strategy group and 144 deaths in the conservative-strategy group (hazard ratio, 1.05; 95% CI, 0.83 to 1.32). CONCLUSIONS Among patients with stable coronary disease and moderate or severe ischemia, we did not find evidence that an initial invasive strategy, as compared with an initial conservative strategy, reduced the risk of ischemic cardiovascular events or death from any cause over a median of 3.2 years. The trial findings were sensitive to the definition of myocardial infarction that was used