Shared electronic health data are an important asset in today’s society. Electronic health records, electronic health data registries, and electronic health research databases are just three examples of electronic data collections in which data relating to health are stored increasingly to allow their use by different actors. The value of these data collections is often in the possibility of exchange. The demand for standardisation and interoperability has been expressed at different levels (healthcare, industry, research, policy,… ). The exchange of data allows collaboration and knowledge-sharing, a requirement to provide an individual patient with the best possible care at every moment and to ensure the highest quality of care within a society. Traditionally, however, data relating to health are not open at all. The data are private, and especially when confined to a healthcare practitioner who is kept by professional secrecy there were no expectations relating to data sharing.