Outline for February 9, 2007

1. Greetings and Felicitations!
2. Chinese Wall Policy
   1. Arises as legal defense to insider trading on London stock exchange
   2. 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)
   3. Intuitive goal: keep one subject from reading different CDs in the same COI, or reading one CD and writing to another in same COI
   4. Simple Security Property: Read access granted if the object (a) is in the same CD as an object already accessed by the subject, or (b) is in a CD in an entirely different COI. Assumes correct initialization
   5. 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
   6. Exceptions: sanitized information
   7. *-Property: Write access is permitted only if (a) read access is permitted by the simple security property; and (b) no object in a different CD in that COI can be read, unless it contains sanitized information
   8. Key result: information can only flow within a CD or from sanitized information
   9. Comparison to BLP: (1) ability to track history; (2) in CW, subjects choose which objects they can access but not in BLP; (3) CW requires both mandatory and discretionary parts, BLP is mandatory only
   10. Comparison to Clark-Wilson: specialization of Clark-Wilson