Security Models in the Password-Capability System

Computer systems today are subject to the increasing problems associated with hackers, viruses, spyware and other undesirable activity. These problems often threaten the confidentiality, integrity or availability of user data held on the systems. Conventional systems such as Windows, Unix and Linux have not proven adequate at protecting the data, in part due to their lack of support for strong security models. In this paper we discuss an operating system called the password-capability system. The system offers a number of powerful security mechanisms. We show that these mechanisms allow the system, unmodified, to support the well-known Bell-LaPadula security model. Furthermore, we suggest minor modifications to the system to enable it to support a broad class of static and dynamic models, including Chinese Wall and Clark-Wilson.