A New Role Hierarchy Model for Role Based Access Control

A new role hierarchy model for RBAC (role-based access control) is presented and its features are illustrated through examples. Some new concepts such as private permission, public permission and special permission are introduced, based on the RRA97 model. Some new role-role inheriting forms such as normal inheritance, private inheritance, public inheritance and special-without inheritance are defined. Based on the ideas mentioned, the new role hierarchy model is formulated. It is easier and more comprehensible to describe role-role relationships through the new model than through the traditional ones. The new model is closer to the real world and its mechanism is more powerful. Particularly it is more suitable when used in large-scale role hierarchies.

Role based access control design using Triadic concept analysis

Role based access control is one of the widely used access control models.There are investigations in the literature that use knowledge representation mechanisms such as formal concept analysis(FCA),description logics,and Ontology for representing access control mechanism.However,while using FCA,investigations reported in the literature so far work on the logic that transforms the three dimensional access control matrix into dyadic formal contexts.This transformation is mainly to derive the formal concepts,lattice structure and implications to represent role hierarchy and constraints of RBAC.In this work,we propose a methodology that models RBAC using triadic FCA without transforming the triadic access control matrix into dyadic formal contexts.Our discussion is on two lines of inquiry.We present how triadic FCA can provide a suitable representation of RBAC policy and we demonstrate how this representation follows role hierarchy and constraints of RBAC on sample healthcare network available in the literature.

Provably Secure Role-Based Encryption with Revocation Mechanism

Role-Based Encryption （RBE） realizes access control mechanisms over encrypted data according to the widely adopted hierarchical RBAC model. In this paper, we present a practical RBE scheme with revocation mechanism based on partial-order key hierarchy with respect to the public key infrastructure, in which each user is assigned with a unique private-key to support user identification, and each role corresponds to a public group-key that is used to encrypt data. Based on this key hierarchy structure, our RBE scheme allows a sender to directly specify a role for encrypting data, which can be decrypted by all senior roles, as well as to revoke any subgroup of users and roles. We give a full proof of security of our scheme against hierarchical collusion attacks. In contrast to the existing solutions for encrypted file systems, our scheme not only supports dynamic joining and revoking users, but also has shorter ciphertexts and constant-size decryption keys.