Can the Bell-LaPadula model emulate the Chinese Wall model?

I have been reading on security policies and the question wether Bell-LaPadula can be used to implement Chinese Wall. Does anyone know more about it?

• Please outline how you think the simulation should work. As it is, the question is a little trite. – Raphael Apr 23 '12 at 6:35
• There is a comparison between Chinese Wall & BLP in the paper by Brewer & Nash. Is it part of the answer ? – Romuald Apr 23 '12 at 12:51
• actually i found the answer by reference book (Computer Security: Art and Science By Matt Bishop)(chapter 7 section 1) suggested by my friend - first the Bell-LaPadula Model cannot capture changes over time. second, more serious problem arises when one considers that subjects in the Chinese Wall model may choose which CDs(company dataset) to access; in other words, initially a subject is free to access all objects. the Bell-LaPadula Model cannot emulate the Chinese Wall model. – siddharth Apr 24 '12 at 6:04
• @siddharth, would you like to make your comment the answer? – Merbs Nov 27 '12 at 17:32
• @Raphael, if siddharth doesn't answer, can you shift his comment into an answer? – Merbs Nov 27 '12 at 17:33

2 Answers

first the Bell-LaPadula Model cannot capture changes over time. second, more serious problem arises when one considers that subjects in the Chinese Wall model may choose which CDs(company dataset) to access; in other words, initially a subject is free to access all objects. the Bell-LaPadula Model cannot emulate the Chinese Wall model.

Ravi S. Sandhu has given a part of a positive answer in his 1992 paper entitled Lattice-Based Enforcement of Chinese Walls (preprint). The idea is to build a lattice from the $n$ Conflict Of Interest (COI) classes defined in the Chinese Wall: elements are tuples of the form $[l_1, \ldots, l_n]$ where $l_i$ is either $\bot$ when no document from class $i$ has been accessed yet or a document's identifier from the class $i$.

To capture the dynamic character of the Chinese Wall policy model, the users' labels have to be updated when he/she reads a document pertaining to a COI class. In this sense, the translation is closer to high-water mark than to pure Bell-LaPadula.

• Link-only answers are troublesome because links break; in particular, if the preprint is no longer available, the information content of this answer if zero for all Elsevier-paywalled visitors. Please give a short summary of the article, i.e. at least the core ideas. – Raphael Apr 1 '15 at 17:18