May 3, 2017 Outline

Reading: Chapters from revised text, §6.5, 8–8.1; [Li89]
Due: Project Progress Report, May 12; Homework #3, May 19

1. Trust models
   1. Policy-based trust management
   2. Reputation-based trust management
2. Chinese Wall Policy
   1. Low-level entities are objects; all objects concerning the same corporation form a CD (company dataset); CDs whose corporations are in competition are grouped into COIs (Conflict of Interest classes)
   2. Intuitive goal: keep one subject from reading different CDs in the same COI, or reading one CD and writing to another in same COI
   3. Simple Security Property: Read access granted if the object:
      1. is in the same CD as an object already accessed by the subject; or
      2. is in a CD in an entirely different COI.
   4. Theorems:
      1. Once a subject has accessed an object, only other objects in that CD are available within that COI;
      2. Subject has access to at most 1 dataset in each COI class
   5. Exceptions: sanitized information
   6. *-Property: Write access is permitted only if:
      1. Read access is permitted by the simple security property; and
      2. No object in a different CD in that COI can be read, unless it contains sanitized information