Designing Trusted Operating Systems

1-Write a set of rules combining the secrecy controls of the BellLa Padula model with the integrity controls of the Biba model.

2-Demonstrate a method for limited transfer of rights in the GrahamDenning model. A limit of one is adequate. That is, give a method by which A can transfer to B right R, with the provision that B can transfer that right to any one other subject. The subject to which B transfers the right cannot transfer the right, nor can B transfer it again.

3-Does the standard Unix operating system use a nondiscretionary access control? Explain your answer.