8
Access Control Mechanisms:
The Gold Standard
·Authenticate principals: Who made a request
-Mainly people, but also channels, servers, programs
(encryption implements channels, so key is a principal)
·Authorize access: Who is trusted with a resource
-Group principals or resources, to simplify management
- Can define by a property, e.g. “type-safe” or “safe for scripting”
·Audit: Who did what when?
·
•Lock  = Authenticate + Authorize
•Deter = Authenticate + Audit
Object
 
Resource
 
Reference
monitor
 
 
Guard
 
Do
 
operation
Request
Principal
Source
 
Authorization
Audit log
Authentication
Policy
1. Isolation boundary
2. Access control
3. Policy