Design and Verification of Loosely Coupled Inter-Organizational Workflows with Multi-Level Security

Abstract

Inter-Organizational Workflows (IOWF) become important as they provide solution for data sharing, heterogeneity in resources and work coordination at global level. However, a secured computing infrastructure like Multilevel Security (MLS) is needed to support today’s vast businesses. In this paper Message Sequence Charts (MSC) are used to specify the positive and negative interactions between cooperating organizations. Petri nets are used to model the workflows in each organization. IOWF is obtained by combining Message Sequence Charts (MSC) and workflows of local organizations. We present an algorithm to incorporate MLS features into IOWFs using Bell-LaPadula security model. In this model security labels of subject and object are verified before the subject can access the object. The algorithm reduces the workflows of participating organizations using the reduction rules while preserving the communication patterns between organizations. We also present an algorithm to identify implicit places in the IOWF with MLS features. Our method and algorithms are illustrated by a running example.