Using the clearances and classifications specified in Chapter 5 Exercise 2 with the BLP security conditions, complete an access control matrix with subjects in {Paul, Anna, Jesse, Sammi, Robin}, objects in {a, b, c, d, e}, and rights in {r, w}.

The objects correspond with the document described in each of parts a-e. The right 'r' should be given if a subject may read an object, and the right 'w' given if a subject may write an object.

CH5 Exercise 2:

Given the security levels TOP SECRET, SECRET, CONFIDENTIAL, and UNCLASSIFIED (ordered from highest to lowest), and the categories A, B, and C, specify what type of access (read, write, both, or neither) is allowed in each of the following situations. Assume that discretionary access controls allow anyone access unless otherwise specified.

1. Paul, cleared for (TOP SECRET, { A, C }), wants to access a document classified (SECRET, { B, C }).
2. Anna, cleared for (CONFIDENTIAL, { C }), wants to access a document classified (CONFIDENTIAL, { B }).
3. Jesse, cleared for (SECRET, { C }), wants to access a document classified (CONFIDENTIAL, { C }).
4. Sammi, cleared for (TOP SECRET, { A, C }), wants to access a document classified (CONFIDENTIAL, { A }).
5. Robin, who has no clearances (and so works at the UNCLASSIFIED level), wants to access a document classified (CONFIDENTIAL, { B }).

Answer: