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I need to design a state machine model to solve conflict of interest in computer security. [I know Chinese wall model but it is an information flow model]

Are there any such existing models?

Any reason as to why we cannot design it as a state machine model?

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Can you clarify what you are after here - is it a regulatory Segregation of Duties model or something else? And what do you mean by state machine in this context? Problems phrased as a "here is my problem, here is what I want to achieve, how can I do this" can get better answers than ones which leave people guessing... – Rory Alsop Jan 31 '12 at 14:27
up vote 2 down vote accepted

Unless you mean something very specific by "state machine model", there is no reason why you couldn't model conflict of interest using a state machine. The Chinese Wall itself can be easily represented as a state-machine, following the traditional BLP approach:

  • a state is defined by the set of current accesses, a function associating each object to a company dataset, and a function associating each company dataset to a conflict-of-interest class.
  • The transition function takes a state and an access, and if the access request is not in conflict with a current access, it is added, otherwise the access is denied.

Ravi Sandhu actually proposed an enforcement of the Chinese Wall model using a lattice-based model, and some of my PhD work was to define some general state-machine model for access control systems, including the Chinese Wall. The section 3.2 of this paper can give you a formal definition of the CW using a state-machine.

I hope that helps, and I can bring more clarifications if wanted.

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Is solving conflict of interest a computable problem? Can we even build a Turing Machine or another type of finite state machine to model somthing like human interest and emotion? Perhaps the CSTheoy Stack Exchange is a better platform for such a question.

Or perhaps State Machines and computablity is the wrong branch of mathmatics... My gut feeling is that Game Theory is a better tool for such a model.

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