Multi-Tenant Access and Information Flow Control for SaaS

Due to multi-tenancy, access control is a very important component in SaaS (Software as a Service), especially for controlling cross-tenant accesses. Due to the potential information flow among multiple tenants, information flow control should also be carefully addressed. Existing models for SaaS access control have some limitations, especially in information flow control. In this paper, we define a new SaaS-AIFC model to provide comprehensive and improved access and information flow control in SaaS. SaaS-AIFC incorporates two advanced features. First, SaaS-AIFC integrates the advanced role mapping technique to govern the cross-tenant accesses. Role mapping is very flexible and can be very efficient for SaaS with a large number of tenants. We integrate role mapping in SaaS by developing a detailed process for mapping establishment and retrieval during validation. Second, we propose a new IFC model in SaaS-AIFC, which tracks the dependency of data objects and uses the dependency information to achieve flexible information flow control. An architecture design for realizing the SaaS-AIFC model is also proposed.