OFFICE HOURS DURING SEMESTER

• Tuesdays: 2:30pm to 3:30pm (room MC384)
• Fridays: 1:30pm to 2:30pm (room MC384)

Most recent announcements are at top, older ones are further down the page.

• link on recent security problems relating to salesforce.com
• 30 Oct 2007: Following up on today's discussion of trusted computing platforms, email was sent to me containing this link to a discussion of commercially available software for copying BluRay disks. [By including this link here, I am neither endorsing nor encouraging the copying of BluRay disks, nor offering any legal opinion on the matter, nor offering a legal opinion on this disclaimer of a legal opinion, nor ...]
• 27 Oct 2007: As of 8pm today, email has been sent out with ciphertexts to be solved for homework 4 and questions in the style of the upcoming exam. [If you did not recieve such an email and are registered in the course, please email me soonest -- although I probably won't see it til Monday, so you may want to contact other people in the class that you know as well to find out as much as you can about what went out.] Enjoy.
• 17 Oct 2007: An interesting example of a presentation that has attracted a bit of attention is Randy Pausch's Last Lecture at CMU.
• 9 Oct 2007: Information regarding next Tuesday's Step 1 writeup was emailed out to everyone on my list of registered students. If you are a registered student and didn't get it, please contact me soonest.
• 6 Oct 2007: Homework 3 has been emailed out as of 9pm. If you didn't get it (and you are registered in the class), contact me.
• 27 Sept 2007: It has been pointed out that the h2.c program has an added quirk to it. Because the variable count gets reset every 40 characters and count is used to determine which character from the key to use, the cycling through the key restarts every 40 characters rather than happening continuously throughout the message. Although this wasn't originally intended, it does not change the problem in any material way, so I am declaring the bug a feature.
• 21 Sept 2007: Homework 2 cipher texts were emailed out Fri Sep 21 23:13:57 EDT 2007. Yesterday a desciption of the h2 program that was used to encode these texts was emailed to everyone.
• 13 Sept 2007: For people interested in how to format their bibliographies and citations, see Harvard Referencing 2007 by Library and Information Service at Curtin University. The wikipedia entry on Harvard referencing provides more general context information.
• 13 Sept 2007: Dark Web: University of Arizona NSF-funded project for web monitoring. A few quotes from the announcement:
  • This is where the Dark Web project comes in. Using advanced techniques such as Web spidering, link analysis, content analysis, authorship analysis, sentiment analysis and multimedia analysis, Chen and his team can find, catalogue and analyze extremist activities online. According to Chen, scenarios involving vast amounts of information and data points are ideal challenges for computational scientists, who use the power of advanced computers and applications to find patterns and connections where humans can not.
  • One of the tools developed by Dark Web is a technique called Writeprint, which automatically extracts thousands of multilingual, structural, and semantic features to determine who is creating 'anonymous' content online. Writeprint can look at a posting on an online bulletin board, for example, and compare it with writings found elsewhere on the Internet. By analyzing these certain features, it can determine with more than 95 percent accuracy if the author has produced other content in the past. The system can then alert analysts when the same author produces new content, as well as where on the Internet the content is being copied, linked to or discussed.
  • Dark Web's capabilities are also being used to study the online presence of extremist groups and other social movement organizations. Chen sees applications for this Web mining approach for other academic fields.
  • "What we are doing is using this to study societal change," Chen says. "Evidence of this change is appearing online, and computational science can help other disciplines better understand this change."
• 12 Sept 2007: Note: this homework will be handed in hardcopy as described in the assignment. You can bring it to class the day due or put it in the course locker. The locker is: 101 (which is on the ground floor of Middlesex College near the center elevator).
• 12 Sept 2007: Homework 1 was emailed out to your UWO accounts at 8:44pm on Wednesday Sept 12th. Please reply to it acknowledging receipt. Also please let me know if you didn't get a copy.
• 12 Sept 2007: A walkthrough of how I deciphered the a4 example that was handed out in class Tuesday (and can be found in ~webber/CS413 on gaul) is in the postscript file report413.1.ps (or pdf file report413.1.pdf). The approach was ad hoc, as it is how it was done last semester and we weren't using the Gaines's book last semester. As mentioned before, I used the awk scripts freq, diagram, and trigram to gather basic statistics. To test a particular guess, I used the gawk script descramble.gawk which reads an enciphered text on standard input and a key from the file unkey and produces a decrypted text. If you look on gaul in the ~webber/CS413 directory, there is an example unkey file (it is the unkey file that corresponds to the key file in the same directory that the scramble script uses to produce the enciphered text in the first place). Thus

      gawk -f scramble.gawk < a1 | gawk -f descramble.gawk
  

  outputs the contents of a1 unchanged. The key file is just a reordering of the numbers from 1 to 25. The unkey file is a list of pairs of letters, the first letter ranging from a to z and the second letter being what you want to map the first letter to. For example, I frequently map unknown letters to _ although one could also map them to upper case versions of themselves if that was more convenient. To do my deciphering, on a unix box, I open three windows. In one window I have a shell loop repeatedly descrambling the cipher text every 5 seconds. In another window, I have the text editor open on the unkey file. The idea is that every time I make a change to the unkey file, 5 seconds later, that change automatically occurs in the window that is running the descrambling script. [In the third window, I opened a text file to keep track of what I tried, providing raw material for the report on how the cipher was cracked.] To see what statistics should be for various situations in English, I consulted various pages referred to on the course web page:
  • Useful English Language Statistics
  • Kevin's Word List Page has links to a bunch of places where people have put together all words in the English (and other) language. Some of them with frequency of usage information.
  • Statistical Distributions of English Text
  • Here is some statistical information that is helpful when trying to solve cryptograms
  The first one above was the most useful. Don't forget, my software views English as having only 25 letters (i.e., i and j are viewed as the same letter).
• 11 Sept 2007: Finished privacy and simple substitution readings. The handout contained examples from the files available in ~webber/CS413 on gaul. The awk scripts freq.gawk, diagram.gawk, and trigram.gawk were used to extract frequency, diagram, and trigram statistics from texts. Email addresses were collected for sending out homework 1. The readings:
  • Information Systems Security: Nature and Scope
  • A Serious Cipher
  were assigned for Friday's class. Note that the first homework is due on the 18th and the paper proposal on the 25th. So expect a handout on the proposal format on Friday and next Tuesday (the 18th) a discussion of the second infrastructure reading: Choosing a project and writing a proposal.
• 10 Sept 2007: You might find interesting the discussion of the Storm Worm botnet, which is being claimed to have grown to roughly 50 million computers:
  • Storm worm botnet more powerful than top supercomputers (Sept 7th) -- linked from Slashdot discussion of same
  • Storm botnet puts up defenses and starts attacking back (Aug 17th)
  • Storm botnet behind Canadian DoS attack (Aug 14th)
  • Storm Worm refuses to die (Mar 6th)
• 10 Sept 2007: CSD Course Policies and Procedures: Student Privacy will be referenced in Tuesday's class, particularly the powerpoint slide presentation: Student Personal Information and the Freedom of Information and Protection of Privacy Act.
• 7 Sept 2007: Notes from today's class:
  • covered first of infrastructure readings on course reading list on how to choose a subject, topic, hypothesis for a paper.
  • covered course outline and associated web information available as of 7 Sept.
  • course textbook is in the bookstore. however, because the class is small, there aren't any pre-printed copies. so what you have to do is get one of the purple coupons (ask at bookstore information if you can't find one for CS 413) and purchase it, which then entitles you to come back in a day or so to pick up a printed copy. (see wikipedia entry on JIT (Just In Time inventory management)).
  • for Tuesday, we have the first reading from the security section of the readings (on privacy policies) and the first reading from the cryptography readings (on substitution ciphers). if you haven't been able to get a copy of the text and would like to do something to prepare a bit on this, as you would expect, the wikipedia entries on privacy and PIPEDA would give some sense of what the privacy discussion will raise and the wikipedia entry on frequence analysis as it relates to simple substitution codes and the first part of the entry on substitution cipher that talks about simple substitution ciphers gives some overview of what Gaines will work through in more detail. Incidently, there is a wikipedia entry for Ann Cavoukian who was one of the authors of the privacy reading selection.
• 6 Sept 2007: link to article on using cell phones as remote bugging devices found in slash dot article on bugging VoIP phones
• 5 Sept 2007: Created Executive Summary as a merger of Course Outline and Reading List without all the legalese. Also created Paper Topics to help people who are looking for ideas (you are definitely NOT required to use one of these topics if you have something else that you like better and fits the requirements of the course).
• 17 Aug 2007: Course Outline available.
• 27 July 2007: The list Readings for CS413 was revised due to copyright issues, removing Adler and van Doran's chapters and replacing it with a chapter from Lannon and Klepp's book.
• 22 June 2007: The copies of the items on Readings for CS413 have been given to the University Bookstore to be collected and sold in place of a textbook for this course. The readings cover three main areas: 1) issues in computer security (and security in general); 2) issues in cryptography with specific focus on cryptanalysis; and 3) readings on how to read the technical literature, organize a paper, and prepare a presentation. The journal articles in the collection can be found online also, but the book chapters are scatterred across many libraries; so, in general, I expect it will be best to get a copy of the bookstore version if you are planning on taking the course. Students will be marked in part on how well they are keeping up with the readings (for more details, see the upcoming revised course outline).
• 22 June 2007: Created announcements page.

I can be contacted by email at webber@csd.uwo.ca . Be sure and include course number in subject line of your email.