Research Area: Privacy Protection
Privacy has become a significant concern in modern society as personal information about individuals is increasingly collected, used, and shared, often using digital technologies, by a wide range of organizations. One goal of this project is to precisely articulate what privacy means in various settings, and whether and how it can be achieved. In other words, we seek to develop conceptual and technical frameworks in which privacy notions (policies) are given precise semantics, algorithms for enforcing such policies, and characterizations of classes of policies that can or cannot be enforced. In addition to general results of this form, another goal of the project is to study specific application domains that raise significant privacy concerns in modern society and to apply these results (or specialized versions thereof) to these domains. Our application domains span healthcare, Web and online social media, and court records.
Outcomes: Specifically, to mitigate privacy concerns, organizations are required to respect privacy laws in regulated sectors (e.g., HIPAA in healthcare, GLBA in financial sector) and to adhere to self-declared privacy policies in self-regulated sectors (e.g., privacy policies of companies such as Google and Facebook in Web services). We investigate the possibility of formalizing and enforcing such practical privacy policies using computational techniques. We formalize privacy policies that prescribe and proscribe *flows* of personal information as well as those that place restrictions on the *purposes* for which a governed entity may use personal information. Recognizing that traditional preventive access control and information flow control mechanisms are inadequate for enforcing such privacy policies, we develop principled audit and accountability mechanisms with provable properties that seek to encourage policy-compliant behavior by detecting policy violations, assigning blame and punishing violators. We apply these techniques to several US privacy laws and organizational privacy policies, in particular, producing the first complete logical specification and audit of all disclosure-related clauses of the HIPAA Privacy Rule.