Assignment 4

For this assignment, each group will take one of the following four scenarios and design a security plan. More specifically, you will flesh out the scenario, create a threat model, come up with a plausible security plan, and analyze the weaknesses of your plan.

1. You are a photojournalist in Syria with digital images you wants to get out of the country. Limited internet access is available at a cafe. Some of the images may identify people working with the rebels who could be targeted by the government if their identity is revealed. In addition you would like to remain anonymous until the photographs are published, so that you can continue to work inside the country for a little longer, and leave without difficulty.

2. You are working on an investigative story about the CIA conducting operations in the U.S., in possible violation the law. You have sources inside the CIA who would like to remain anonymous. You will occasionally meet with these sources in but mostly communicate electronically. You would like to keep the story secret until it is published, to avoid pre-emptive legal challenges to publication.

3. You are reporting on insider trading at a large bank, and talking secretly to two whistleblowers. If these sources are identified before the story comes out, at the very least you will lose your sources, but there might also be more serious repercussions — they could lose their jobs, or the bank could attempt to sue. This story involves a large volume of proprietary data and documents which must be analyzed.

4. You are working in Europe, assisting a Chinese human rights activist. The activist is working inside China with other activists, but so far the Chinese government does not know they are an activist and they would like to keep it this way. You have met the activist once before, in person, and have a phone number for them, but need to set up a secure communications channel.

These scenario descriptions are incomplete. Please feel free to expand them, making any reasonable assumptions about the environment or the story — though you must document your assumptions, and you can’t assume that you have unrealistic resources or that your adversary is incompetent.

Start by creating a threat model, which must consider:

  • What must be kept private? Specify all of the information that must be secret, including notes, documents, files, locations, and identities — and possibly even the fact that someone is working on a story.
  • Who is the adversary and what do they want to know? It may be a single person, or an entire organization or state, or multiple entities. They may be very interested in certain types of information, e.g. identities, and uninterested in others. List each adversary and their interests.
  • What can they do to find out? List every way they could try to find out what you want secret, including technical, legal, and social methods.
  • What is the risk? Explain what happens if an adversary succeeds in breaking your security. What are the consequences, and to whom? Which of these is it absolutely necessary to avoid?

Once you have specified your your threat model, you are ready to design your security plan. The threat model describes the risk, and the goal of the security plan is to reduce that risk as much as possible.

Your plan must specify appropriate software tools, plus how these tools must be used. Pay particular attention to necessary habits: specify who must do what, and in what way, to keep the system secure. Explain how you will educate your sources and collaborators in the proper use of your chosen tools, and how hard you think it will be to make sure everyone does exactly the right thing.

Also document the weaknesses of your plan. What can still go wrong? What are the critical assumptions that will cause failure if it turns out you have guessed wrong? What is going to be difficult or expensive about this plan?

Include in your writeup (5 pages max):

  • A more detailed scenario, including all the assumptions you have made to flesh out the situation.
  • A threat model answering the four questions above.
  • A security plan including tools, procedures, necessary habits.
  • A training plan, explaining how you are going to teach everyone involved to execute the security plan.
  • An analysis of the vulnerability of your plan. What can still go wrong?

Due last class, Dec 10.

 

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