This week was short, due to the final and the week ending on Saturday. Just as we studied the first half of Chapter 8 in Week 4, we studied the second half this week. As we saw before, this chapter focuses on security. We looked at SSL as it is used to secure TCP at the transport layer. We also learned about IPSec, which secures IP datagrams at the network layer. Finally, we looked at firewalls and and IDS systems which provide operational security.