These questions are related to design principles for secure…
These questions are related to design principles for secure systems. I. Consider a security screening setting like the one that is done at airports before travelers are allowed to board flights. Assume a certain airport uses the following screening protocols.1. Everyone, except those who are explicitly exempted, must undergo the security screening.2. All travelers go through the first screening stage. A subset of travelers are also flagged for a second screening.3. Once successfully screened, travelers only have access to the areas of the airport where their gates are located. What security design principle can be used to explain each of the above choices made for air travel security? Explain your answers. (2+2+2)II. The “Reflections on Trusting Trust” paper described a trojan in a compiler binary that could not be detected even if we had access to and examined the source of the compiler. We discussed how the defense-in-depth principle can help us detect if the trojan exists in a compiler by using two independently developed compilers when at least one of them is correct. We could determine if one of the compilers has the trojan but could not ascertain which one is malicious. To answer this question, the following idea is suggested. Instead of two, we will get three independently developed compilers such that no more than one could be malicious.1. If at least two of the compilers are good, can we use these three compilers to detect the bad one when one exists? (1 pts.)2. Explain your answer to question 2.1. More specifically, if your answer is no, explain why this is not possible. If the answer is yes, show how the bad compiler can be identified. (3 pts.)