Chinese Wall

Conflict of Interest (COI) - occurs when and individual’s judgment or motivation may be impaired due to pre existing biases.

The goal of Chinese Wall is to prevent any conflicts of interest

CW is dynamic, meaning permissions actively change as a subject navigates the system

It is a hybrid model - it is concerned with both confidentiality and integrity

• Confidentiality because it aims to prevent subjects from accessing sensitive data that could be detrimental to the organization

• Integrity because it aims to ensure data is Falsified or corrupted in service to a COI

To understand CW, you have to consider objects, company datasets, and COI classes

• An object refers to some item of info that relates to a company; this is the same definition of object we’ve used

• A company dataset is a collection of objects pertaining to a single company.

  • Ex. Having an Apple or Chevron CD

• A COI class is a set of CD’s belonging to competing companies, such that any two CDs pulled from the class would be in competition

• COI is a collection of CD’s that are collections of Objects

Data in the CW model can be sanitized or unsanitized

• Sanitized Data: refers to info that’s already public or could be published with no harm to the company

  • Sanitization: Any sensitive data removed by info is released

• Unsanitized data: refers to info that is not public, and could result in harm to the company if publicized

• CW model is concerned with limiting access to unsanitized data

Simple Security Condition

• A subject can read an object if any of the following are true:

  • 1. The subject has already read from the object’s dataset

  • 2. Nothing the subject has read before belongs to the object’s COI class

  • 3. The object is sanitized and therefore safe for anyone to view

* Property

• A subject can write to an Object if both of the following conditions are true:

  • The simple security conditions permits S to read O.

  • All unsanitized objects S can read belong to O’s dataset.

The Simple Security Condition and the * Property result in the following:

• The flow of sanitized info is unrestricted

• The flow of unsanitized info is confined to its own CD

• A subject can access only one CD in each COI class

• In each COI class, the mini. num. of subjects needed to access every object is equal to the number of CDs in the COI class

• Access history affects future access (model is dynamic is what that means)

The CW makes some assumptions that are flawed

• CDs in different COI classes may still be in competition; it would be nearly impossible to compartmentalize all possible conflicts of interest away from one another.

• Likewise, CDs in the same COI might not actually be in conflict with one another.

• Consequently, it is important to define COI classes according to common interest, not according to the type of business conducted