Access Control What’s New?

Security Controls Access Control Inference Control Flow control CSCE 824 - Farkas

Access Control Protection objects: system resources for which protection is desirable Memory, file, directory, hardware resource, software resources, etc. Subjects: active entities requesting accesses to resources User, owner, program, etc. Access mode: type of access Read, write, execute CSCE 824 - Farkas

Access Control Requirement Cannot be bypassed Enforce least-privilege and need-to-know restrictions Enforce organizational policy Theoretical Properties: Consistent Complete CSCE 824 - Farkas

Access Control Access control: ensures that all direct accesses to object are authorized Protects against accidental and malicious threats by regulating the reading, writing and execution of data and programs Need: Proper user identification and authentication Information specifying the access rights is protected form modification CSCE 824 - Farkas

Access Control Overview Access control components: Access control policy: specifies the authorized accesses of a system Access control mechanism: implements and enforces the policy Separation of components allows to: Define access requirements independently from implementation Compare different policies Implement mechanisms that can enforce a wide range of policies CSCE 824 - Farkas

Closed v.s. Open Systems Closed system Open System yes no no yes (minimum privilege) (maximum privilege) Access requ. Access requ. Allowed accesses Disallowed accesses Exists Rule? Exists Rule? yes no no yes Access permitted Access denied Access permitted Access denied CSCE 824 - Farkas

Access Control Models Discretionary Access Control Mandatory Access Control Role-Based Access Control Attribute-based Access Control Usage-based Access Control Context-based Access Control … CSCE 824 - Farkas

Policy Compliance How can we model both high-level and low-level security policies in one framework? How can we determine whether the low-level policy and current system configuration is compliant to the high-level policy?

Compliance Checking Framework High-level policy 1 Detect Conflicts and Violations 4 6 Report Refinement 2 3 5 5 KB – Ontology and Refinement Patterns (Concept-level): Common to all Domain-specific Domain-data (Instance): System configuration, Low-level security policies Domain-data (Instance): Role-assignment, Organization structure

What else? Go from binary decision to …maybe? Delegation ??? Provisional Access Control Obligation Delegation ??? CSCE 824 - Farkas

Next Class Inference Control CSCE 824 - Farkas