Rational Trust Modeling

Trust models are widely used in various computer science disciplines. The main purpose of a trust model is to continuously measure trustworthiness of a set of entities based on their behaviors. In this article, the novel notion of "rational trust modeling" is introduced by bridging trust management and game theory. Note that trust models/reputation systems have been used in game theory (e.g., repeated games) for a long time, however, game theory has not been utilized in the process of trust model construction; this is where the novelty of our approach comes from. In our proposed setting, the designer of a trust model assumes that the players who intend to utilize the model are rational/selfish, i.e., they decide to become trustworthy or untrustworthy based on the utility that they can gain. In other words, the players are incentivized (or penalized) by the model itself to act properly. The problem of trust management can be then approached by game theoretical analyses and solution concepts such as Nash equilibrium. Although rationality might be built-in in some existing trust models, we intend to formalize the notion of rational trust modeling from the designer's perspective. This approach will result in two fascinating outcomes. First of all, the designer of a trust model can incentivise trustworthiness in the first place by incorporating proper parameters into the trust function, which can be later utilized among selfish players in strategic trust-based interactions (e.g., e-commerce scenarios). Furthermore, using a rational trust model, we can prevent many well-known attacks on trust models. These two prominent properties also help us to predict behavior of the players in subsequent steps by game theoretical analyses

Trust-Building through Social Media Communications in Disaster Management

open4Social media provides a digital space – a meeting place, for different people, often representing one or more groups in a society. The use of this space during a disaster, especially where information needs are high and the availability of factually accurate and ethically sourced data is scarce, has increased substantially over the last 5-10 years. This paper attempts to address communication in social media and trust between the public and figures of authority during a natural disaster in order to suggest communication strategies that can enhance or reinforce trust between these bodies before, during and after a natural disaster.openM. G. Busà; M. T. Musacchio; S. Finan; C. FennelBusa', MARIA GRAZIA; Musacchio, MARIA TERESA; S., Finan; C., Fenne

Has the Unified Budget Undermined the Federal Government Trust Funds?

In order to ease the burden on workers during the retirement of the baby boom generation, the 1983 Social Security Reforms set payroll taxes above the level needed to pay current benefits, thus partially prefunding the baby boomers' retirement. The military and civil service retirement programs followed suit in the mid-1980s and switched from pay-as-you-go financing to funded systems. The excess income generated by these retirement programs was held in the federal trust funds, which have accumulated almost $3 trillion since the reforms took place. However, this paper presents evidence that the trust fund build-up may not help future generations due to the adoption of the Unified Budget in 1970. The Unified Budget includes trust fund receipts as income and trust fund payments as expenditures. The empirical evidence suggests that attempts to balance the Unified Budget while the trust funds were generating surpluses has led to increased government spending and personal and corporation income tax cuts within the rest of the federal government. There is no evidence of increased government saving as a result of the trust fund accumulations. An alternate theory of increased national saving is also explored, where increased payroll taxes accompanied by decreased income taxes induces higher personal saving. This mechanism, suggested by Diamond, also does not appear to have significantly enhanced the wealth of future generations.

Optimizing trust prediction in digital business ecosystem

The process of predicting the future trust value of an entity, based on its past value is a challenging issue. The prediction process is even more imperative in the scenario where in the interaction would take place at a future point in time. Being able to determine the confidence value of the predicted trust value is of prime importance to enable optimized trust prediction. In this paper we propose a set of metrics for determining the confidence level in the predicted trust value

Optimizing for confidence - Costs and opportunities at the frontier between abstraction and reality

Is there a relationship between computing costs and the confidence people place in the behavior of computing systems? What are the tuning knobs one can use to optimize systems for human confidence instead of correctness in purely abstract models? This report explores these questions by reviewing the mechanisms by which people build confidence in the match between the physical world behavior of machines and their abstract intuition of this behavior according to models or programming language semantics. We highlight in particular that a bottom-up approach relies on arbitrary trust in the accuracy of I/O devices, and that there exists clear cost trade-offs in the use of I/O devices in computing systems. We also show various methods which alleviate the need to trust I/O devices arbitrarily and instead build confidence incrementally "from the outside" by considering systems as black box entities. We highlight cases where these approaches can reach a given confidence level at a lower cost than bottom-up approaches.Comment: 11 pages, 1 figur

Trustworthiness and Motivations

Trust can be thought of as a three place relation: A trusts B to do X. Trustworthiness has two components: competence (does the trustee have the relevant skills, knowledge and abilities to do X?) and willingness (is the trustee intending or aiming to do X?). This chapter is about the willingness component, and the different motivations that a trustee may have for fulfilling trust. The standard assumption in economics is that agents are self-regarding, maximizing their own consumption of goods and services. This is too restrictive. In particular, people may be concerned with the outcomes of others, and they may be concerned to follow ethical principles. I distinguish weak trustworthiness, which places no restrictions on B’s motivation for doing X, from strong trustworthiness, where the behaviour must have a particular non-selfish motivation, in finance the fiduciary commitment to promote the interests of the truster. I discuss why strong trustworthiness may be more efficient and also normatively preferable to weak. In finance, there is asymmetric information between buyer and seller, which creates a need for trustworthy assessment of products. It also creates an ambiguity about whether the relationship is one of buyer and seller, governed by caveat emptor, or a fiduciary relationship of advisor and client. This means that there are two possible reasons why trust may be breached: because the trustee didn’t realise that the truster framed the relationship as a fiduciary one, or because the trustee did realise but actively sought to take advantage of the trust. Correspondingly, there are two possible types of agent: normal people who are not always self-regarding and who are trust responsive (if they believe that they are being trusted then they are likely to fulfill that trust), and knaves, after Hume’s character who is always motivated by his own private interest. We can increase the trustworthiness of normal people by getting them to re-frame the situation as one of trust, so they will be strongly trustworthy (i.e. change of institutional culture), and by providing non-monetary incentives (the correct choice of incentive will depend on exactly what their non-selfish motivation is). Knaves need sanctions, which can make them weakly trustworthy. However, this is a delicate balance because sanctions can crowd out normative frames. We can also increase the trustworthiness of financiers by making finance less attractive to knaves; changing the mix of types in finance could help support the necessary cultural change

The Silver Anniversary of the United States’ Exclusive Economic Zone: Twenty-Five Years of Ocean Use and Abuse, and the Possibility of a Blue Water Public Trust Doctrine

Sustainably managing marine ecosystems has proved nearly impossible, with few success stories. Ecosystem management failures largely stem from the traditional sector-by-sector, issue-by-issue approach to managing ocean-borne activities—an approach that is fundamentally unable to keep pace with the dynamics of coupled human, ecologi cal and oceanographic systems. In the United States today there are over twenty federal agencies and thirty-five coastal states and territories operating under dozens of statutory authorities shaping coastal and ocean policy. Among marine ecologists and policy experts there is an emerging consensus that a major overhaul in U.S. ocean governance is necessary. This Article suggests that the public trust doctrine—an ancient legal concept that is already incorporated in U.S. state coastal laws—can uniquely provide a unifying concept for U.S. federal ocean governance. Though the public trust concept can be located in the legal systems of many countries, it robustly manifests in the United States, where it has historically protected the public’s rights to fishing, navigation, and commerce in and over navigable waterways and tidal waters. In its most basic form, the doctrine obliges governments to manage common natural resources, the body of the trust, in the best interest of their citizens, the beneficiaries of the trust. Today the public trust doctrin e is integral to the protection of coastal ecosystems and beach access in many states and has even made its way into state constitutions. It would be simple, and seemingly logical, to assume that the same fiduciary responsibility of states to protect public trust uses of their waters extends to all marine resources within the United States’ 200-mile Exclusive Economic Zone (EEZ). However an artificial line has been drawn around state waters, and the legal authority and responsibility of the U.S. government to protect public trust resources in the vast space of its EEZ (the largest of any country on earth) have never been fully and expressly established. Securing the place of the public trust doctrine in U.S. federal oceans management would be valuable, given the immense pressure to exploit EEZ resources, the failure of the current regulatory approach, improved scientific understanding of the interconnected nature of ocean ecosystems, and the growing demand for sustainable management of ocean resources. This Article will outline the development of states’ public trust doctrines; discuss the expansion of U.S. sovereignty over its neighboring ocean waters during the twentieth century; analyze possible avenues for expanding the doctrine to federal waters; and consider how a federal public trust doctrine could clarify some specific emerging issues in U.S. oceans management. At the heart of our analysis lie three questions: (1) does a federal public trust doctrine exist; (2) if so, can we rightfully extend it to include the entirety of the U.S. ocean waters; and (3) could the doctrine provide the missing catalyst for federal agencies to manage the use of U.S. ocean resources in a coordinated, sustainable fashion

A Bayesian model for event-based trust

The application scenarios envisioned for ‘global ubiquitous computing’ have unique requirements that are often incompatible with traditional security paradigms. One alternative currently being investigated is to support security decision-making by explicit representation of principals’ trusting relationships, i.e., via systems for computational trust. We focus here on systems where trust in a computational entity is interpreted as the expectation of certain future behaviour based on behavioural patterns of the past, and concern ourselves with the foundations of such probabilistic systems. In particular, we aim at establishing formal probabilistic models for computational trust and their fundamental properties. In the paper we define a mathematical measure for quantitatively comparing the effectiveness of probabilistic computational trust systems in various environments. Using it, we compare some of the systems from the computational trust literature; the comparison is derived formally, rather than obtained via experimental simulation as traditionally done. With this foundation in place, we formalise a general notion of information about past behaviour, based on event structures. This yields a flexible trust model where the probability of complex protocol outcomes can be assessed

Multi-Country Study on Trusted Partners among Youth: Eritrea, Tanzania, Zambia, and Zimbabwe

ObjectivesExplore youth's definitions of "trust"Establish criteria youth use to determine the trustworthiness of partnersIdentify types of individuals youth believe they can and cannot "trust"Examine trust's influence on sexual decision-making and STI/HIV risk perceptionIdentify how sexual partners violate trust and the effects on sexual decision-makingStudy designData were collected in October 2001 as part of a regional Behavior Change Communication (BCC) strategy in East and Southern Africa. Country programs chose to participate in research based on project priorities and levels of interest in participating in a regional BCC strategy. Four county programs agreed to collect and share data, Eritrea, Tanzania, Zambia, and Zimbabwe.A total of 33 focus groups were conducted. Research teams in each country used the same discussion guide and pretested the guide prior to data collection. Discussion groups lasted between an hour and an hour and a half, were audiotaped, and transcribed into English. Each research team conducted two discussion groups in the major urban area composed of the following strata: males 15-19 years, females 15-19 years, males 20-24 years, and females 20-24 years. The Zambia program conducted one additional focus group with males aged 15-19.FindingsExplore youth's definition of "trust" and criteria used to determine trustworthinessThe major components of trust did not vary greatly across countries. Youth in all countries placed a high value on sexual fidelity and its role in trusted partnerships. Youth believed that partners met through family or friends are more trustworthy than those met in bars or nightclubs. In addition, youth in all countries expressed that trusted partners must pass informal assessments, dress appropriately, demonstrate appropriate social conduct, talk sweetly to each other, come from the right neighborhood, meet one another's family, be punctual for appointments/dates, and remain emotionally committed to one another. Eritrean youth appeared to place greater importance on the roles that religion, virginity, and marriage (or intent to marry) play in establishing trust than youth from other countries.Differences in criteria for trust were more apparent by gender. In terms of testing partners' trustworthiness, females discussed passive ways of questioning partners, while males discussed elaborate methods for entrapping females in lies. Males were concerned with partners' sexual reputation and appearance. Females were primarily concerned with partners' emotional commitment, willingness to accept responsibility for pregnancies, and ability to display affection in public in order to demonstrate intimacy and trust.Identify types of individuals youth believe they can and cannot "trust"Across countries, youth place prospective partners into groups that can and cannot be trusted according to key attributes and behaviors. Similar to the findings above, most participants said that youth that come from good families, are well respected in the community, are religious, do not drink, avoid bars and nightclubs, and are faithful can be trusted. Youth believe that they cannot trust anyone outside of committed, monogamous relationships. Male participants added that virgins can be trusted.Examine trust's influence on sexual decision-making and STI/HIV risk perceptionYouth do not appear to take effective preventive measures with trusted partners. Trust can blind them to their risk for STIs/HIV and render them unwilling to explore partners' sexual histories. Sex usually occurs early in relationships and condom use remains low. When youth use condoms, they are more likely to incorporate them into casual than trusted relationships, or use them for pregnancy prevention rather than protection from STIs/HIV. Condoms are usually abandoned once relationships appear to be serious and partners fail to show signs or symptoms of STIs or HIV infection. There were few differences in risk perception and risk behavior across countries; however, male participants in Zambia reported that they discuss their sexual histories, while participants from other countries said that couples rarely discuss their sexual histories.Identify how sexual partners violate trust and the effects on sexual decision-makingInfidelity represents the most serious violation of trust and usually results in the end of relationships. A common theme across all countries was youth's refusal to learn from past experiences and apply them to future sexual decision-making. Even when trust is broken, youth fail to apply lessons learned to new relationships, repeating the same scenarios of trust, infidelity and exposure to STIs/HIV.Programmatic implicationsYouth must understand that partners' trustworthiness and character are independent of their risk for STIs/HIV. Although a checklist may help youth select a good partner, unprotected sex with this or any other person must be perceived as risky. Youth must also personalize their risk for STIs/HIV and avoid thinking that only people outside of their community are at risk for infection. It is likely that interpersonal communication campaigns or other community-level activities will help achieve an improved risk perception. Finally, in order to communicate new and appropriate levels of personal risk assessment, programs should strive to achieve broad social support, if not pressure for, consistent condom use, knowledge of one's own HIV status as well as that of all partners, and delay of sexual activity where possible