Paper 2010/471

Privacy-preserving Sharing of Sensitive Information

Emiliano De Cristofaro, Yanbin Lu, and Gene Tsudik

Abstract

The need for controlled sharing of sensitive information occurs in many realistic everyday scenarios, ranging from critical (e.g., national security) to mundane (e.g., social networks). A typical scenario involves two parties, at least one of which seeks some information from the other. The latter is either willing, or compelled, to share information. This poses two challenges: (1) how to enable this type of sharing such that parties learn no (or minimal) information beyond what they are entitled to, and (2) how to do so efficiently, in real-world practical terms. In this paper, we discuss the concept of Privacy-preserving Sharing of Sensitive Information (PSSI) and provide an efficient database system implementation. The PSSI system functions as a privacy shield to protect parties from disclosing their respective sensitive information. Although seemingly simple, the design and deployment of PSSI prompts a number of new and interesting practical challenges, that are addressed in this paper. We present extensive experimental results that attest to the practicality of attained privacy features.