2000 年 20 巻 2 号 p. 125-134
High-quality healthcare information services among healthcare institutes distributed across a wide area network have usually been provided using one of two methods. The more common method is to exchange the contents of healthcare information in a predefined format, usually text. Message transfers by HL7 and EDIFACT are examples of this. However, this method has disadvantagesdue to the loss of information caused by serializing real objects in a healthcare information system. The other method, less common, is to access healthcare information directly from a remote site. In this approach information is accessed using the same healthcare software application programs as are used internally in a healthcare institute, but from another healthcare institute across a wide area network. In this paper, we propose a new secure framework based on public key infrastructure for providing dynamic healthcare information services through a wide area network. It providessecurity of service, scalability of connected networks and seamless connection between intranets and the Internet. Although the framework refers to Kerberos, it is actually completely different in that it is based on public key infrastructure. In addition a proxy server is introduced to the framework as a countermeasure to denial-of-service attacks. We conducted preliminary experiments demonstrating that the framework possesses the same level of processing efficiency as Kerberos and about three times more robustness against denial-of-service attacks.
