Notes for February 2, 1998

1. Greetings and felicitations!
   1. Reading: Pfleeger, pp.228-253; Garfinkel & Spafford, pp. 71-137
2. Puzzle
   1. Point is that root introduces a security flaw by its existance; secure systems don't have them
3. 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
4. Privilege in Languages
   1. Nesting program units
   2. Temporary upgrading of privileges
5. 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