1. RBAC Role-Based Access Control

2. RBAC: “?”
Aim:- A framework which simplifies management of permissions by associating permissions with roles, and users with appropriate roles.
Roles can be granted new permissions as new applications and systems are incorporated, and permissions can be revoked from roles as needed.
The role is more stable because an organization’s activities or functions usually change less frequently in contrast to the users’ membership to roles.
Vishwas Patil, TIFR.

3. RBAC: Principles RBAC is policy-neutral by itself.
Vishwas Patil, TIFR.

4. RBAC: Family RBAC0 is the base model.
RBAC1 adds the concept of role hierarchies.
RBAC2 adds constraints.
RBAC3 = RBAC1 + RBAC2
Role Hierarchy (RH)
users
(U)
roles
(R)
permiss-
ions (P)
Permission
Assignment (PA)
User Assignment (UA)
Vishwas Patil, TIFR.

5. user: human being / autonomous agent / computer
role: job function with associated semantics regarding the authority and responsibility conferred on a member of the role.
permission: an approval of a particular mode of access to one or more objects in the system.
user assignment: many-to-many relation between U and R.
permission assignment: many-to-many relation between R and P.
session (S): mapping of one user to possibly many roles.
Vishwas Patil, TIFR.

6. RBAC0
PA  P x R
UA  U x R
user : S  U, a function mapping each session si to the single user user(si) (constant for the session’s lifetime)
roles : S  2R, a function mapping each session si to a set of roles roles(si)  {r | (user(si),r)  UA} (which can change with time) and session si has the permissions rroles(si) {p | (p,r)  PA}.
Vishwas Patil, TIFR.

7. RBAC1 U, R, P, S, PA, UA, and user are unchanged from RBAC0
RH  R x R is a partial order on R called the role hierarchy relation, written as 
roles : S  2R is modified from RBAC0 to require a roles(si) {r | (r'  r)[(user(si), r' )  UA]} (which can change with time) and session si has the permissions rroles(si) {p | (r''  r)[(p, r'')  PA]}.
Vishwas Patil, TIFR.

8. RBAC2
RBAC2 is unchanged from RBAC0 except for requiring that there be a collection of constraints that determine whether or not values of various components of RBAC0 are acceptable.
Only acceptable values will be permitted.
Ex. mutually exclusive roles, prerequisite roles
A role hierarchy can be considered as a constraint!
Vishwas Patil, TIFR.

9. RBAC3
RBAC3 combines RBAC1 and RBAC2 to provide both role hierarchies and constraints.
Vishwas Patil, TIFR.

10. RBAC: Discussion e-CRM applications, ORACLE, Operating Systems
Other advantages/disadvantages
NIST standards
Scalability, manageability issues
Vishwas Patil, TIFR.