1. 1 © Ravi Sandhu OM-AM and PEI Prof. Ravi Sandhu

2. 2 © Ravi Sandhu THE OM-AM WAY Objectives Model Architecture Mechanism What? How? AssuranceAssurance

3. 3 © Ravi Sandhu LAYERS AND LAYERS  Multics rings  Layered abstractions  Waterfall model  Network protocol stacks  Napolean layers  RoFi layers  OM-AM  etcetera

4. 4 © Ravi Sandhu OM-AM AND MANDATORY ACCESS CONTROL (MAC) What? How? No information leakage Lattices (Bell-LaPadula) Security kernel Security labels AssuranceAssurance

5. 5 © Ravi Sandhu OM-AM AND DISCRETIONARY ACCESS CONTROL (DAC) What? How? Owner-based discretion numerous ACLs, Capabilities, etc AssuranceAssurance

6. 6 © Ravi Sandhu OM-AM AND ROLE-BASED ACCESS CONTROL (RBAC) What? How? Objective neutral RBAC96, ARBAC97, etc. user-pull, server-pull, etc. certificates, tickets, PACs, etc. AssuranceAssurance

7. 7 © Ravi Sandhu SERVER MIRROR ClientServer User-role Authorization Server

8. 8 © Ravi Sandhu SERVER-PULL ClientServer User-role Authorization Server

9. 9 © Ravi Sandhu USER-PULL ClientServer User-role Authorization Server

10. 10 © Ravi Sandhu PROXY-BASED ClientServer Proxy Server User-role Authorization Server

11. 11 © Ravi Sandhu THE OM-AM WAY Objectives Model Architecture Mechanism What? How? AssuranceAssurance

12. 12 © Ravi Sandhu PEI Security and system goals (objectives/policy) Policy models Enforcement models Implementation models Necessarily informal Specified using users, subjects, objects, admins, labels, roles, groups, etc. in an ideal setting. Security analysis (objectives, properties, etc.). Approximated policy realized using system architecture with trusted servers, protocols, etc. Enforcement level security analysis (e.g. stale information due to network latency, protocol proofs, etc.). Technologies such as Cloud Computing, Trusted Computing, etc. Implementation level security analysis (e.g. vulnerability analysis, penetration testing, etc.) Software and Hardware Concrete System