Editorial SACMAT 2007

This special issue consists of enhanced versions of five of the articles presented at the ACM Symposium on Access Control Models and Technologies (SACMAT) held in Sophia Antipolis, France, in June 2007. SACMAT has become the premier forum for presentation of research results and experience reports on leading edge issues of access control including models, systems, applications, and theory. The mission of the symposium is to share novel access control solutions that fulfill the needs of heterogeneous applications and environments as well as to identify new directions for future research and development. The article “Privacy-aware Role-Based Access Control” by Q. Ni, E. Bertino, J. Lobo, C. Brodie, C.-M. Karat, J. Karat, and A. Trombetta extends the popular role-based access control model with complex and realistic privacy policies. The article describes the security model as well as the design and implementation of a system based on this privacy-aware role-based access control also known as P-RBAC. The authors also compare and contrast their system with those based on other privacy models including P3P, EPAL, and XACML. The article “On the Consistency of Distributed Proofs with Hidden Subtrees” by A. Lee, K. Minami, and M. Winslett describes a mechanism for distributed proofs appropriate for pervasive systems. The authors show that consistency constraints may be enforced in a proof system where the complete proofs are not available to the queriers. They also present their performance results that show that the overhead is modest. The article “A Logical Specification and Analysis for SELinux MLS Policy” by B. Hicks, S. Rueda, L. St. Clair, T. Jaeger, and P. McDaniel states that the SELinux multilevel security policy is difficult to verify due to its richness. They then describe a logic-based specification and implementation of this specification in Prolog. They also develop some analyses to test the properties of a policy. In the article “The Role Mining Problem: A Formal Perspective” by J. Vaidya, V. Atluri, and Q. Guo, the authors define the Role Mining Problem as the problem of discovering an optimal set of roles from existing user permissions. The article analyzes the theoretical bounds of the Role Mining Problem and shows the reducibility of this problem to several problems already identified in the data mining and data analysis literature. Subsequently, the authors borrow the existing implementation solutions that guide their research. The article “A Framework to Enforce Access Control Over Data Streams” by B. Carminati, E. Ferrari, and K. L. Tan describes an access control model for data streams. The authors specify a secure algebra for data stream query processing and describe the design of a system for access control enforcement.