February 13, 2019 Outline
Reading: text, §7, 8; paper [WB04]
Due: Project Progress Report, due February 15, 2019; Homework 3, due February 22, 2019
- Countermeasures
- Blocking near endpoint systems
- Blocking at endpoint systems
- Amplification attacks
- 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
- Clinical Information System Security model
- Intended for medical records; goals are confidentiality, authentication of annotators, and integrity
- Patients, personal health information, clinician
- Assumptions and origin of principles
- Access principles
- Creation principle