Abstract
Over the last years, the Internet has become the backbone of the information processing environments. The peer to peer concept is ideal for the development of a healthcare data sharing system because it respects the internal autonomy of each of the participating agencies (e.g. physicians, clinics, pharmacies, laboratories, etc). In this paper we introduce interoperability and data sharing settings considering a healthcare data management system where two parties or peers exchange and share data without any middleware data management system. We assume that databases in peers or data sources are created independently and may have semantic inter-dependencies with regards to data. Each peer specifies pair-wise data sharing settings/mappings with acquainted peers for sharing and exchanging related data.