Any interaction—from a simple transaction to a complex collaboration—can be successful only if an adequate level of trust exists between interacting entities. One of the more important components of trust of an entity in its interaction partner is its reliance that the partner is both willing and able to protect entity’s privacy. This is as true in the cyberspace as in social systems.
The need for privacy is broadly recognized by individuals, businesses, the government, the computer industry, and academic researchers. Examples are shown in Table 1. The growing recognition of the importance of privacy is motivated not only by users’ sensitivity about their personal data. Other factors include business losses due to privacy violations, and enactments of federal and state privacy laws. Even more important, the quest for the promised land of pervasive computing will fail if adequate privacy guarantees are not provided.