Notes for November 13, 1998

1. Greetings and Felicitations!
2. Puzzle of the Day
3. Privilege in OSes
   1. None (original IBM OS; protect with password, or anyone can read it)
   2. Fence, base and bounds registers; relocation
   3. Tagged architectures
   4. Memory management based schemes: segmentation, paging, and paged segmentation
4. User identification
   1. Go through UNIX idea of "real", "effective", "saved", "audit"
   2. Go through notion of "role" accounts; cite Secure Xenix, DG, etc.
   3. Go through PPNs (TOPS-10) and groups
   4. Review least privilege
5. Privilege in Languages
   1. Nesting program units
   2. Temporary upgrading of privileges
6. Different forms of access control
   1. UNIX method
   2. ACLs: describe, revocation issue
   3. MULTICS rings: (b₁, b₂) access bracket - can access freely; (b₂, b₃) call bracket - can call segment through gate; so (4, 6, 9) as example
   4. Capabilities: file descriptors in UNIX