Question 1

Both the Clark-Wilson and Biba models address the issue of integrity. Given that integrity models

have three major goals, specify the integrity goals and indicate the goals addressed by each model.

Question 2

Suppose that the Clark-Wilson security model is used by a bank to implement an Internet banking system so that customers can access their accounts and perform transactions online using an Internet

browser on a computer. From the customers perspective, give an example of the relevant part of the Internet banking system best describes.

Constrained data items (CDIs)

Unconstrained data items (UDIs)

Transformation procedures (TPs)

For each example, briefly describe your reasoning.

Question 3

With the help of an example, explain the fundamental difference between incremental backup and

differential backup.

Question 4

It has been suggested that an old hard drive can be securely erased by encrypting the whole drive with

a sophisticated algorithm and key, and then destroy the key. Discuss whether this software approach

to data erasure is sufficient.