pHealth occurs in uncontrolled and unsecure environment where predefined organizational trust does not exist. To be accepted by users, pHealth requires a privacy model where privacy is a personal property, i.e., a person can perform own will and define policies which regulate how personal health information (PHI) is used. Privacy and trust are interconnected concepts. Therefore, before beginning to use pHealth services, the person needs practical and reliable information that enables her or him to determine the trustworthiness level of services.

To avoid the use of blind trust, organizations, researchers, policymakers, and standardization organizations have proposed the use of dynamic context-aware policies for privacy management in pHealth. To make meaningful privacy decision, a person should understand the impact of selected policy rules on the processing of PHI in different situations.

In this paper, the use of computational trust information for defining privacy polies and reducing their number is proposed. A trust value and understandable trust attributes enable a person to tailor privacy policies requested for trustworthy use of pHealth services. Trust attributes proposed are derived from privacy concerns existing in open ubiquitous environment. These attributes also force pHealth services providers to publish information needed for trust calculation and in this way to support openness and transparency.