INFORMATION

• This assignment will be given in two parts.
  • Part I is given below on Thursday Nov 28th.
  • Part II will be given out next week on Monday Dec 3nd.
    
    
    
• This assignment covers the material from unit G in our syllabus: Computer Security and Computation.
• The purpose of this hw is to give you experience with investigating cookies stored on your computer and to reinforce your understanding of Encryption and PGP.
• You may find the pages on security in the Reed text helpful (pages 181 - 184). Lecture Notes G1 are useful as well
  
  
  
• Part I of this assignment is worth 5 points, or 5% of your term grade.

1. For this assignment, you will write the answers to the 5 questions below in the text file.
2. Name the text file yourname-HWG.txt, where yourname is your last name. Mine would be jansen-HWG.txt. Failure to do this will result in lost points!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
   
3. When you are completed with the questions, e-mail the text file as an attachment (no need to zip it) to me:
   1. My email address is: chipp@sci.brooklyn.cuny.edu

PART I. (Every question is 1 pnt each)

On-line Questions : Cookies (Questions 1 - 3 will be done online with a web-browser).

To begin this homework, change the browser settings to alert you before the browser accepts a cookie:

(It is possible that on your computer/browser, you may have to change the settings a little differently. If you get stuck, try the browser Help.)

• Using Netscape, go to Edit > Preferences > click on the + sign next to Privacy and Security (on the left side). When the list under Privacy and Security expands, click on Cookie and choose "Ask me before storing a cookie" (on the right side).
• Using Explorer, go to Tools > Internet Options > click on the Privacy tab. Click on the Advanced button. Check the box that says "Override automatic cookie handling" and then choose "prompt" on both the sets of radio buttons. Click on OK. Then Click on Apply and OK.

Question 1 Visit several sites and see whether or not they set cookies on your computer. Indicate whether there are any "third party cookies", i.e. cookies that are being set by sites that are different from the page you are viewing.

1. www.cnn.com
2. www.yahoo.com - Try a search
3. www.google.com - Try a search
4. www.brooklyn.cuny.edu
5. www.lesley.edu

Question 2 Go to cookiedemo.com and try the Cookie Demo. Set a cookie, then go to some other pages and come back to cookiedemo.com. Did it remember what cookies you like?

Question 3 Do the Analyzer at Network-Tools.com. Do the Analyzer at Network-Tools.com twice.

1. Is a cookie set when you visit the Network-Tools.com site?
2. Whose cookie is it? Is it from www.privacy.net?
3. What type of information is collected about your browser and your computer?
4. Did the site collect your IP address?
5. What other information was collected through the cookie that surprised you?
   
   

Security Questions : Encryption and PGP

Question 4 Encryption Types

1. What is the difference between symetric and asymetric encryption?
2. What kind of encryption is PGP: symetric or asymetric?
3. What kind of encryption was used by this mafia boss: symetric or asymetric?

Question 5 Caesar's Encryption

Here is a ciphertext encoded using the Caesar Encryption mentioned in Lecture G1.

KNFJAN CQN RMNB XO VJALQ

Given a Key of 9 that was used to encrypt it. Decrypt this message.