La Trobe University, Bendigo

Division of Information Technology

BITCNE: Computer Networks

Assignment 3 1999

New questions may appear on this assignment sheet

Answer ONE ONLY of the following questions.

1. There are a variety of electronic payment (or electronic cash) systems designed for payment for goods and services on the Web. Not many of these have, to my knowledge, actually been widely implemented. You task in this question is to discover any electronic cash systems which have been actually implemented on commercial websites. We aren't interested in the traditional credit-card approach, and I don't want a report on how the different e-cash systems operate; rather I want to know who is using these systems right now.
2. This question is about network security. Your task is to investigate some practical aspects of public key cryptosystems. In particular, you should look at PGP (Phil Zimmerman's Pretty Good Privacy package), widely available on the Internet and installed on the department's Unix systems. As part of your assessment, you are required to create a personal PGP public/private key pair and then send, in a secure way, an email message to your lecturer, such that no one except your lecturer can read it. You must then provide your public key to the lecturer in such a way that the lecturer is certain of the origin of the message. The email message should consist of a report which covers what you did, why you did it, and a brief discussion of the current status of PGP.
3. Use tkined to build a network management system for the Bendigo campus, monitoring most of the interesting pieces of equipment in the campus network. You should submit the .tki file for your system, along with a brief description of what it does, and how it does it, so that we can run it and check its operation. Obviously this question is only relevant to people who are taking the subject on campus, although if you're located somewhere with an interesting network perhaps you could set up tkined and use it there. Or perhaps you could use one of the other many SNMP packages available, see below.
4. The best (free) SNMP package for Unix is tkined. There are many other SNMP-based network monitoring packages in existence, particularly for Windows systems, although there are a few for Macs as well. Discover two (or more) such packages, install them and report on their usefulness.
5. One of the hot issues in the Internet at present, particularly in Australia, is that of censorship. Even as I write this assignment question, the Australian parliament is debating the introduction of new laws to "censor the Internet". One of the key points raised by the opponents of 'net censorship is the technical difficulty of implementing it, and the ease with which any kind of censorship could be circumvented. Your task here is to investigate the technical aspects of the problem of censorship. You are not to look at the political aspects of censorship, nor the issue of so-called "take down" notices for offensive material. I want you to simply research the way in which the proposed legislation proposes to filter offensive material from entering Australia, and whether it will work. Note that reference information for this question is available on several Web sites in Australia.
6. Network programming question: write a computer program, in the language of your choice, which will perform a HTTP/1.0 HEAD request for a specified Web page, to check that the page actually exists. Then modify your program to read in a list of URLs, and check each one in turn for existence. Finally, read an arbitrary text file, extract referenced URLs from it (a referenced URL appears in the context of a "<A HREF=" markup) and check their existence. This program is a basic "link rot" detector, and is a very useful utility. If you intend answering this question, please contact the lecturer before you begin -- there are some issues I would like to make clear.
7. Investigate SOCKS. This software is frequently used as a circuit-level firewall, and is something that you could come across in the Real World(tm). Tell me how it works, how you configure it, and what it can do for you. Incidentally, it might be easiest if you stick with SOCKS V.4 - the V.5 version is somewhat more complicated.
8. Investigate steganography, and in particular how it relates to encryption and the Internet. This is a fun topic, because you should discover lots of interesting software (eg, one I occasionally use is called snow) and applications.
9. As before, another topic with the explicit prior approval of your lecturer. If you are interested in something under this heading, you must email me (with [BITCNE] at the start of the subject line, as usual) stating your proposal.

You should expect to write something between 1500 and 3000 words on the topic of your choice, although this is not mandatory. You have two options for submission of your assignment: traditional hard copy (paper) form, or as a text/html email attachment, as in earlier assignments. Your choice of submission format will not, in any way, affect the mark which you obtain, although students choosing electronic submission should consult the guidelines available on the BITCNE home page before proceeding to submit via this method. Submissions must, in general, adhere to the requirements of the LaTrobe University, Bendigo Assignment Guide.

This assignment carries 20% of your mark for Computer Networks.

Due Date: End of semester 1, 1999.
Lecturer and tutor: Phil Scott 5444 7277, p.scott@latrobe.edu.au