Data security in European healthcare information systems
This thesis considers the current requirements for data security in European healthcare systems and establishments. Information technology is being increasingly used in all areas of healthcare operation, from administration to direct care delivery, with a resulting dependence upon it by healthcare staff. Systems routinely store and communicate a wide variety of potentially sensitive data, much of which may also be critical to patient safety. There is consequently a significant requirement for protection in many cases. The thesis presents an assessment of healthcare security requirements at the European level, with a critical examination of how the issue has been addressed to date in operational systems. It is recognised that many systems were originally implemented without security needs being properly addressed, with a consequence that protection is often weak and inconsistent between establishments. The overall aim of the research has been to determine appropriate means by which security may be added or enhanced in these cases. The realisation of this objective has included the development of a common baseline standard for security in healthcare systems and environments. The underlying guidelines in this approach cover all of the principal protection issues, from physical and environmental measures to logical system access controls. Further to this, the work has encompassed the development of a new protection methodology by which establishments may determine their additional security requirements (by classifying aspects of their systems, environments and data). Both the guidelines and the methodology represent work submitted to the Commission of European Communities SEISMED (Secure Environment for Information Systems in MEDicine) project, with which the research programme was closely linked. The thesis also establishes that healthcare systems can present significant targets for both internal and external abuse, highlighting a requirement for improved logical controls. However, it is also shown that the issues of easy integration and convenience are of paramount importance if security is to be accepted and viable in practice. Unfortunately, many traditional methods do not offer these advantages, necessitating the need for a different approach. To this end, the conceptual design for a new intrusion monitoring system was developed, combining the key aspects of authentication and auditing into an advanced framework for real-time user supervision. A principal feature of the approach is the use of behaviour profiles, against which user activities may be continuously compared to determine potential system intrusions and anomalous events. The effectiveness of real-time monitoring was evaluated in an experimental study of keystroke analysis -a behavioural biometric technique that allows an assessment of user identity from their typing style. This technique was found to have significant potential for discriminating between impostors and legitimate users and was subsequently incorporated into a fully functional security system, which demonstrated further aspects of the conceptual design and showed how transparent supervision could be realised in practice. The thesis also examines how the intrusion monitoring concept may be integrated into a wider security architecture, allowing more comprehensive protection within both the local healthcare establishment and between remote domains.