CST311 - Week 35

I started off this week studying for the midterm, which I took on Friday. I studied by reviewing my own notes, as well as the study guide written by the textbook authors that was provided for us on ILearn. I also looked over all of the quizzes and assignments and made sure I understood how to perform all the problems and calculations from the optional worksheets. I feel that I studied well and am happy with the grade I got on the midterm. We're halfway through the course already!

This week, we also read the beginning of Chapter 8 on Security in Computer Networks. We learned about the two basic types of cryptography: symmetric-key and public-key. The examples featured messages sent between Alice and Bob, with Trudy trying to intercept (pictured left). To ensure message integrity, cryptographic hash functions are used along with a MAC, message authentication code. The use of a digital signature, by encrypting a message with the individual's private key can provide verification of the individual, as well as validate that the signature was not forged. The CA, Certification Authority validates entities and provides certificates binding a public key to a specific, verified entity. The next section discussed the authentication protocol, which uses a number called a nonce that is used only once to authenticate an entity at the current time. Lastly, the text provided a case study of secure e-mail. I found the topics this week to be extremely interesting!

Lastly, we had Lab 6: Mininet TCP Congestion Control, in which we used iperf to provide the value of cwnd which we then plotted in a line graph.