# 6.857: Computer and Network Security (Spring 2012)

## Announcements

### Paper details, and presentation dates set

Presentation dates are posted here.

The project paper should be similar to a research paper - it should talk about the problem studied, the previous work (if any), the approach taken, the results found, and conclusions. In particular you should point out your project extends previous work on the subject! The paper should have an excellent bibliography, nice figures, be well-organized, and be well-written. A good paper is probably around 25 pages, though some groups may need more space, and less may be fine in some cases.

### Problem Set 5 is posted

Problem Set 5 is posted, and is due May 4th.

### Problem Set 4 posted

PS4 is posted. To complete the homework, you'll need this paper by Adam Kalai. You'll also need the datasets of keys, which have 1000, 10000, 100000, 1000000 keys. (You can download these files together in a zip file here).

### Practice Number Theory Problems

To sharpen your number theory skills, take a look at the following supplementary exercises, with a few additional supplementary problems here.

### Project Proposal Due Friday

Your group of size 3 or 4 should turn in a multiple page project proposal by 11:59 PM this Friday, 3/23, as an email to 6857-staff.

### Problem Set 3 out

Problem set 3 is out- find your PS3 group here, and then work on Problem Set 3 together. This is the last problem set for which the course staff will be assigning groups. PS3 will be due on Monday, March 19th to avoid giving you work over Spring Break- due to the shortened time, you'll find that the problem set is shorter, too.

### Problem Set 2 out

Problem set 2 is out- find your PS2 group here, and then work on Problem Set 2 together. You'll need to look at both Desai's and Bellare and Rogaway's variable input length symetric encryption schemes.

### Problem Set 1 Submission

Reminder: Problem Set 1 solutions are due this Friday, Feb 24, at 11:59pm. Solutions should be emailed in PDF format to the **6857-staff** mailing list. Please only submit one set of solutions per group, but make sure all your names are on it!

### Nash Cryptosystem Implementation

Prof. Rivest has coded up an implementation of the Nash cryptosystem in Python. The comments are useful in terms of things to think about- both general ideas, and line-by-line for each implementation decision.

### Problem Set 1

Problem Set 1 has been posted. It involves a cryptosystem by Nash, transcribed here.

The groups for Problem Set 1 have also been posted. If you are registered for credit or have signed up online, you should be listed there. If you are not in a group, please fill out the signup form and email 6857-tas.

### Lecture schedule

Reminder: In spite of what the registrar may say, 6.857 has *two*
lectures per week in *different* rooms:
Mondays in 66-110 and Wednesdays in 56-114 (both 11:00-12:30).
Wednesdays are a *lecture*, not a recitation. (We are planning to add a recitation
section on Fridays, later on.) If you missed lecture 2/8, please be sure to see the
posted lecture notes, read the course information sheet, come to class on Monday, and
see the TA, and sign up online.

### Course signup

If you're interested in taking 6.857 (either for credit or as a listener), please fill out the signup sheet here.

### Welcome to 6.857!

Welcome to 6.857, Spring 2012.