CS 261, Spring 2021
Computer Security

  David Wagner (daw@cs, 733 Soda Hall, 642-2758)

  Mon Wed, 1:00-2:30pm, online

Office Hours:
Mondays 2:30pm after class, Wednesdays 2:30pm after class, Thursdays 12:30-1 on Zoom


See the schedule of lectures. Each class you will read about 2 research papers on some topic and write a summary of each.


Class project: 40%
Problem sets: 20%
Scribe notes: 10%
Discussion lead: 15%
Paper summaries and class discussion: 15%


See the schedule for the list of readings.

You are required to read each paper before lecture. In addition, you will be required to write a brief summary of each paper you read, responding to specific questions I have assigned. The assigned questions are linked next to each day's reading. Your summary does not need to be formal (you may use bullet lists, incomplete sentences, etc.), and it may be brief (one or two lines per question is fine), but it should reflect a thoughtful critical assessment of the paper.

Submit your summary on Ed as a private post, with the appropriate tag, by 11am on the day of class when the reading is assigned (i.e., 2 hours before class starts). Don't email it to me -- submit on Ed.

You are not required to read the additional reading for the discussion lead.


Students are expected to engage actively in class discussions. We will hold class via Zoom; all students are expected to be present and with camera turned on, to support active engagement. If this raises any concerns for you, please contact me.


You will do a class project involving independent research, in groups of 2-3.

Please see the project page for more details about the project.

Problem Sets

There will be approximately 2-3 homework assignments throughout the semester. They will appear on the course webpage as they are assigned. Homework due dates will be enforced strictly. Late homeworks will not be accepted.


Work on your own when doing homeworks. You may use any source you like (including other papers or textbooks), but if you use any source not discussed in class, you must cite it.

Scribe notes

You will be expected to write scribe notes for one lecture. If you were chosen to scribe, email me an PDF file with your scribe notes within one week after the lecture you are assigned to scribe. You don't need to duplicate the paper, but try to record the main ideas and points that came out in lecture and the discussion during class (including the part led by a student discussion lead).

Discussion leads

Each lecture, we will have one discussion lead. The job of a discussion lead is to lead an interactive discussion among the class on a topic related to the day's topic, for 15 minutes. The lead should identify some questions or group activity or discussion topic to discuss among the class. The goal is to help your fellow students learn or be exposed to some interesting idea.

I have assigned 1-2 papers for each lead to read (in addition to the day's assigned readings), which you can use to stimulate ideas for a possible discussion topic. For instance, you could pick a simplified version of the problem solved by that paper or a small subproblem tackled in the paper, describe the problem to the class, invite the class to brainstorm solutions, and walk through tradeoffs of candidate solutions with the class. However, you are not obligated to follow that approach, or to follow the paper that is assigned to you -- you can go a different direction if you prefer. You are under no obligation to convey any the ideas in the paper assigned to you to read; and even if you do follow it, you should definitely not expect to try to convey all or even most of the ideas in that paper, but rather pick one single interesting idea. I would prefer that you structure your time slot as an interactive discussion instead of a non-interactive presentation of the paper.

If you were chosen to be discussion lead, please email me a brief summary of your plans for your 15-minute discussion slot, at least 24 hours before lecture, so I can make sure to avoid duplicating your plans and coordinate with you have if I have any feedback. If you are struggling with ideas or how to structure your time, contact me and I am available to help.

Online discussion

I have set up an online site for discussion using the Piazza platform. Please don't hesitate to use that for discussion, questions, or anything else that might be of interest to others in the class.


We will be discussing attacks. None of this is in any way an invitation to undertake these in any fashion other than with informed consent of all involved parties. If in any context you are uncertain about where to draw the line, come talk with me first.


It looks like the course is currently full. I don't plan to expand the course size. I will rely on the Registrar's system for who is admitted. I will not be able to admit any undergraduates this semester due to the high demand from graduate students; sorry.


The EECS department provides a way to report incidents of concern related to climate; you are welcome to use it.

David Wagner, daw@cs.berkeley.edu, http://www.cs.berkeley.edu/~daw/.