The challenge for improvement of quality and efficiency of health care systems causes the development and promotion of “Shared Care” in all developed countries. Distribution, decentralisation, and specialisation of health care must be joint with an extended communication and co-operation between the different care providers. Fulfilling the shared care paradigm, care supporting health information systems has to be distributed, interoperable, and scaleable too. Communication and co-operation across organisational, regional, and even national boundaries is bearing high threats and risks regarding security and privacy of medical and personal information of both patients and health professionals. Involved in several security projects funded by the European Union, the Medical Informatics Department and the regional Clinical Cancer Registry at the University of Magdeburg are piloting a secure regional distributed medical record system for cancer diseases. Requirements, solutions, and experiences are presented and discussed.