Computer Science 530 - Homework 3 -- Fall 2007

Due: Wednesday, November 7, 2007, 11:00 p.m.

1. Discuss the difference between signature based and anomaly based intrusion detection. What are the advantages and disadvantages of each approach. Provide examples of attacks that would be undetected by each approach, but detected by the other approach. Is there a similar set of approaches for detecting viruses, and if so describe the approaches and provide examples of their use.
2. Discuss the differences in the protection provided by encryption of a data stream using SSL or TLS, and encryption of a message or object such as that provided by PGP. Consider who has access to the plaintext data, the complexity of managing keys, and the protections provided such as confidentiality, integrity, and non-repudiation. Provide an example of a problem for which each approach is best suited.

INSTRUCTION:

The report must be submitted by 11:00 p.m. on November 7, 2007. The report should be approximately 3 pages, or roughly 1200 to 1500 words. To submit your report you will use the DEN Blackboard assignent submission mechanism. You will use this method regardless of whether you are an on-campus student or a DEN student.

How to submit Assignment #3:

• STEP 0. Please make sure your name and student ID number are on the document you turn in.
• STEP 1. Please login to DEN.USC.EDU, and select csci530.
• STEP 2. Please select "Assignment" in the menu.
• STEP 3. Please select "view/Complete Assignment #3".
• STEP 4. Please select "File To Attach" to attach your report. (NOTE: PDF, MS WORD, ASCII TEXT ONLY! Other formats are NOT acceptable.)
• STEP 5. Please select "Submit" button. (If you select *SAVE* button instead of *submit*, then the TA cannot view your report for grading.)

It is the individual student's responsibility to follow the submission instruction. Submissions that do not follow this instructions, e.g., submitted late, or only "Saved" and not submitted. may be penalized or may not be graded at all. Note that the submission box for the assignment may dissapear from the class web site at 11PM on November 7, i.e. the submission deadline.

GUIDELINE:

This is a lot to cover in so few words - so our advice is to write a first pass at your answer that is longer, and then edit out material that is redundant or not to the point. The use of tables can be very effective in conveying your ideas in a small area, but the tables must be integrated with your textual discussion, and not the only item in your submission.