Keeping sensitive information private in a public world is a common concern to users of digital credentials. A digital credential may contain sensitive attributes certifying characteristics about its owner. X.509v3, the most widely used certificate standard, includes support for certificate extensions that make it possible to bind multiple attributes to a public key contained in the certificate. This feature, although convenient, potentially exploits the certificate holder's private information contained in the certificate. There are currently no privacy considerations in place to protect the disclosure of attributes in a certificate. This thesis focuses on protecting sensitive credential content during trust negotiation and demonstrates, through design and implementation, the privacy benefits achieved through selective disclosure. Selective disclosure of credential content can be achieved using private attributes, a well-known technique that incorporates bit commitment within digital credentials. This technique has not been thoroughly explored or implemented in any prior work. In this thesis, a protocol for issuing and showing credentials containing private attributes is discussed and suggested as a method for concealing and selectively revealing sensitive attributes bound to credentials during trust negotiation. To demonstrate greater privacy control within a credential-based system, private attributes are incorporated into TrustBuilder, an implementation of trust negotiation. With access control at the attribute level, TrustBuilder gives users greater control over their private information and can improve the success rate of negotiations. TrustBuilder also demonstrates how credentials with private attributes can eliminate risks normally associated with exchanging credentials, such as excessive gathering of information that is not germane to the transaction and inadvertently disclosing the value of a sensitive credential attribute.

<p>The term ‘stigma’ is formally defined as the assignment of negative perceptions to an individual because of perceived difference from the population at large (The Free Online Dictionary by Farlex). Stigma, pervasive on a micro, mezzo and macro level serves to devalue individuals who have been diagnosed with mental illness and the support systems that are designed to assist them. Although efforts have been made in public awareness campaigns to reduce the stigma associated with mental illness, stigma continues to limit opportunities and restrain individuals from living full and enriching lives. Many individuals “suffer in silence” often resorting to maladaptive coping mechanisms to manage symptoms.</p> <p>The purpose of this study was to uncover the short term and long term impact of stigma from the perspective of those who are labelled with mental illness in order to gain a deeper and more accurate understanding of the effects of such on life satisfaction. Existing literature suggests that the result of anticipated and experienced stigma can affect individuals in multiple ways: diminished self-esteem, self-efficacy, and self-worth; social withdrawal; identity ambivalence; secrecy and reduced opportunities (employment, housing, income).</p> <p>This research utilized qualitative semi-structured interviews and photo elicitation to gain an understanding of experienced and anticipated stigma as perceived by those with mental illness. Theoretically, the study was influenced by the modified labelling theory which posits that social and internalized stigma associated with mental illness is a societal creation in that its’ development exists as a result of disapproving social attitudes about mental illness. Eight individuals with various diagnosed mental disorders participated in the study. The findings suggest that for each of the participants in this study, initial dealings with the mental health care system and its’ components are likely to impact individuals negatively but once effective treatment, medication stabilization and a good practitioner are found, the experience becomes positive and empowering to individuals. Regardless of the level to which internalized stigma exists, all participants engaged in acts of secrecy, withdrawal, passing and selective disclosure adversely affecting life satisfaction. The implications for practice include recognizing the structural factors that influence clients’ internalization of stigma which likely contributes to feelings of empowerment and control over ones’ life. Revealing mental health status to others may be beneficial in contributing to an improved quality of life satisfaction.</p> / Master of Social Work (MSW)