An Application of the (max, +) Algebra to Information Flow Security

Confidentiality is one of the most important topics in computer security research. In order to check and ensure confidentiality, information flow models are widely used. These models support the specification of valid flows of information. Furthermore, they provide means to formally check whether a given system fulfills a certain security property within this model. In this paper, we propose an information flow model which accounts for different security concerns. In this model, each participant of the communication may have a different role and, thus, different clearance levels for each security concern. Moreover, we demonstrate the application of the (max, +) algebra to analyze the security of a given system and provide an algebraic check for the security property. This includes a method to derive assignments of security clearance levels that do not invalidate the system´s security.