Archive for October, 2009

Midterm review

October 22, 2009

I have written a brief summary of material that will be covered on the midterm. Please read the caveat at the top, though.

HW2, part II

October 22, 2009

By now you should all have access to another team’s code that you can try to attack. If that is not the case, you should email the TA immediately.

Because of the delay in getting these to you, and due also to the midterm next week, I am going to move the deadline by 48 hours to Nov. 3, 11:59 PM.

Lecture 15

October 21, 2009

This lecture covered database privacy. I hope you enjoyed the lecture — I find this material endlessly interesting since the attacks can be so subtle. It is quite amazing to me that database privacy has been formalized only recently (as I will discuss in class on Nov. 2).

Next Monday there will be a guest lecturer — Paul Syverson will be speaking about Tor, a real-world anonymous network. It promises to be a great lecture! (And in case that doesn’t convince you to come, any material covered is fair game for the final…)

Next Wednesday is the midterm, which will cover all the material through today’s lecture. I will post a review sheet by the end of the week.

Lectures 13-14

October 20, 2009

The past two lectures have focused primarily on access control. We reviewed different mechanisms for ensuring access control (e.g., access control matrices, access control lists, and capablities), following by different policies for access control (discretionary AC, several varieties of mandatory AC, and role-based AC).

We wrapped up the module on system security with a brief discussion of code-based access control and trusted computing.

Lecture 12

October 12, 2009

We wrapped up our discussion of ‘circumventing crypto’ with a brief mention of timing/power attacks. For further information about the original attacks, plus suggested countermeasures, see the website of the company Cryptography Research (founded by Paul Kocher, the one who first published the idea of power attacks).

After this, we began our module on systems security by giving an overview and discussing general principles.

In class I also announced that the midterm will be on Oct. 28, covering material through the class on Oct. 21.

PS: In class I mistakenly said that the Saltzer-Schroeder was required reading. While the material we covered in class is, as always, fair game, you are not required to read the article.

Lecture 11

October 7, 2009

In this lecture we continued our discussion of “crypto pitfalls”, focusing on several case studies that I hope you found interesting. As examples of bad crypto, we covered the flaws in WEP and the gross mistakes in the Diebold e-voting system. We also highlighted the recent attack on SSH as an example of where even the best crypto can potentially be “broken” when the system does not match the ideal model in which security is proved.

At the end of class, we looked at the recent “cold boot” attacks that demonstrate how crypto is worthless if the adversary can extract the keys.

I was planning on covering timing/power attacks in today’s lecture, but will pick up with this next time. Then we will move on the a few lectures on “system security”.

I’d love to hear people’s reactions to the articles, once you have read them.

Lecture 10

October 5, 2009

In today’s lecture we continued to cover “crypto pitfalls”, and also began discussing some case studies from the paper “Why Cryptosystems Fail” (linked from the course website).

Several students raised some interesting points in class, and I hope those students will provide pointers to the examples they mentioned.


October 2, 2009

Homework 2 is now out. Start early! Note also that this homework must be done in teams of 2 students. You can use the class forum if you need help finding a partner. (I believe there are an even number of students in the class, so it should be possible for everyone to pair up.)