Abuse & Misuse Cases


The purpose of this activity is to get you acquainted with writing abuse and misuse cases in tandem with writing use cases.


This activity is for groups of 4-6 people. Your instructor will assign each team a different system. For this exercise, your team is in charge of coming up with the system's functionality, as well as specifying the requirements. Please assign the following roles:


  1. Give your system a title. Start up a document on GoogleDocs (make sure it has edit sharing permissions with the instructor), call it "Requirements Specification for X" where X is will title of your system. Also, place the following headers in the document to be filled out:
  2. Conduct a requirements elicitation session with the customer. The customer is in charge of brainstorming the functionality, but must be reasonable as the instructor can override any customer decision. The scribe takes informal notes from this meeting (no requirements just yet).
  3. Fill in the Overview section based on your requirements elicitation session. What is the system, in general? What are the general security goals of the system? Who are the actors (both regular and malicious)?
  4. Begin to brainstorm some good use cases. Write the titles of 3-5 use cases. Don't write the scenarios just yet.
  5. Elaborate on one use case. Write the main flow, about 4-10 steps. Be specific about what information is being exchanged. You may add alternative flows if you see the need, but they are not required for this exercise.
  6. Now write both a misuse case and abuse case for that use case. A few notes:
  7. Sketch another use case (no need to be super-detailed on the use case). Write a detailed abuse AND misuse case for that. Thus, your requirements document should have a good mix of misuse and abuse cases.
  8. Now that you have defined multiple different abuse and misuse cases, generalize those into security requirements that are not specific to any particular use-case, but are specific to your system. Document it this way:
  9. Be ready to discuss your abuse and misuse cases with the rest of the class.

Submission & Grading

Share your document with your instructor and course assistant. They will provide feedback on the document, but this will not be graded.