Discuss the algebra of authentication and its implications for privacy. That is, assume a situation with two-factor authentication, and call the factors A and B. Consider the four cases in which each one is strong or weak. What conclusions would you draw about the results: weak A and weak B; weak A and strong B; strong A and weak B; strong A and strong B? Does order matter? Does it matter if both factors are of the same type (what you know, what you have, what you are)? What happens if you add a third factor, C?