On the Expressive Power of the Unary Transformation Model

The Transformation Model TRM was recently introduced 10 in the literature by Sandhu and Ganta. TRM is based on the concept of transformation of rights. The propagation of access rights in TRM is authorized entirely by existing rights for the object in question. It has been demonstrated in the earlier work that TRM is useful for expressing various kinds of consistency, con dentiality, and integrity controls. In our previous work 10 , a special case of TRM named Binary Transformation Model BTRM was de ned. We proved that BTRM is equivalent in expressive power to TRM. This result indicates that it su ces to allow testing for only two cells of the matrix. In this paper we study the relationship between TRM and the Unary Transformation Model UTRM. In UTRM, individual commands are restricted to testing for only one cell of the matrix whereas individual TRM commands can test for multiple cells of the matrix. Contrary to our initial conjecture of 10 , we found that TRM and UTRM are formally eq...

• Type: Conference
• Year: 1994
• Where: ESORICS
• Authors: Ravi S. Sandhu, Srinivas Ganta
• Keywords: ESORICS 1994, Expressive Power, Individual Trm Commands, Security Privacy, Transformation Model TRM