February 12, 2024 Outline
Reading: text, §7.4, 8.1
Due: Extra Credit #C, due February 14; Project Progress Report, due February 16; Homework #3 due February 21
Module 27 (Reading: text, §7.4)
- Countermeasures
- Manipulate opening of connection
- Control which packets get through, or the rate at which they get through
- Amplification attacks
Module 28 (Reading: text, §8.1)
- Brewer-Nash (Chinese Wall) Policy
- 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)
- Intuitive goal: keep one subject from reading different CDs in the same COI, or reading one CD and writing to another in same COI
- Simple Security Property: Read access granted if the object:
- is in the same CD as an object already accessed by the subject; or
- is in a CD in an entirely different COI
- Theorems:
- Once a subject has accessed an object, only other objects in that CD are available within that COI;
- Subject has access to at most 1 dataset in each COI class
- Exceptions: sanitized information
- *-Property: Write access is permitted only if:
- Read access is permitted by the simple security property; and
- No object in a different CD in that COI can be read, unless it contains sanitized information
- Key result: information can only flow within a CD or from sanitized information
- Aggressive Chinese Wall model
- Comparison to BLP
- Comparison to Clark-Wilson