Question

Hi I need someone to generate a BLP Lattice system with an access control matrix as such:

2 Generate a BL lattce structured system where the objects and subjects are appropriately levelled to give access consistent with the access control matrix below. You need to deseribe the process by which you obtain your lattice. R and W correspond, respectively, to read and append. You are to use only the mandatory BLP rules, and a default allow in place of the discretionary rule. Be sure to add a level as necssary to ensure this is a lattice.

Answer 1

If I recall correctly, BLP is an example of a MAC (mandatory access control) system, while the access matrix you post is a simple RBAC system. We can't necessarily 'convert' between the two. MAC is based on the idea of labels (secret, top-secret etc), preventing information flow in certain directions between labels. RBAC is a completely 'flat' system; users are given rights to objects without regards to information flow.

So, you can't 'convert' the access matrix, but you can arrive at a lattice based on the access matrix by 'inventing' the extra information needed. Try to categorize the objects into MAC levels, and then assign users to those levels. We may arrive at conflicts: a user that has write access to a lower level (which violates the no-write-down property of BLP). Perhaps you could split the user in two, but in reality you wouldn't want people using multiple accounts. Another solution is to upgrade the classification of some objects, but that may give rise to new conflicts.