ABSTRACT
User privacy is related to the concepts of "personal data" and personally identifiable information (PII). User privacy is also related to concepts of a user's anonymity, unobservability, and unlinkability. This chapter focuses on the privacy of individuals immersed in a world saturated with information technology. The problem of people's privacy has become more important than ever due to the accessibility of digital data describing not only a person's possessions, actions, and relationships with other people, but even their wishes, intentions, and emotions. The problem of privacy breach is critical since it may lead to restrictions of individual liberty and erosion of our society's foundations of trust. The presence of biometric identifiers makes it possible to bind a person's virtual identity used in cyberspace with his/her real-world identity, or to bind several persons' virtual identities with each other. Cloud-based data processing requiring privacy assurance can be successfully deployed in private clouds.
